Search results for: larval parasitoid
Commenced in January 2007
Frequency: Monthly
Edition: International
Paper Count: 120

Search results for: larval parasitoid

60 The Use of Rule-Based Cellular Automata to Track and Forecast the Dispersal of Classical Biocontrol Agents at Scale, with an Application to the Fopius arisanus Fruit Fly Parasitoid

Authors: Agboka Komi Mensah, John Odindi, Elfatih M. Abdel-Rahman, Onisimo Mutanga, Henri Ez Tonnang

Abstract:

Ecosystems are networks of organisms and populations that form a community of various species interacting within their habitats. Such habitats are defined by abiotic and biotic conditions that establish the initial limits to a population's growth, development, and reproduction. The habitat’s conditions explain the context in which species interact to access resources such as food, water, space, shelter, and mates, allowing for feeding, dispersal, and reproduction. Dispersal is an essential life-history strategy that affects gene flow, resource competition, population dynamics, and species distributions. Despite the importance of dispersal in population dynamics and survival, understanding the mechanism underpinning the dispersal of organisms remains challenging. For instance, when an organism moves into an ecosystem for survival and resource competition, its progression is highly influenced by extrinsic factors such as its physiological state, climatic variables and ability to evade predation. Therefore, greater spatial detail is necessary to understand organism dispersal dynamics. Understanding organisms dispersal can be addressed using empirical and mechanistic modelling approaches, with the adopted approach depending on the study's purpose Cellular automata (CA) is an example of these approaches that have been successfully used in biological studies to analyze the dispersal of living organisms. Cellular automata can be briefly described as occupied cells by an individual that evolves based on proper decisions based on a set of neighbours' rules. However, in the ambit of modelling individual organisms dispersal at the landscape scale, we lack user friendly tools that do not require expertise in mathematical models and computing ability; such as a visual analytics framework for tracking and forecasting the dispersal behaviour of organisms. The term "visual analytics" (VA) describes a semiautomated approach to electronic data processing that is guided by users who can interact with data via an interface. Essentially, VA converts large amounts of quantitative or qualitative data into graphical formats that can be customized based on the operator's needs. Additionally, this approach can be used to enhance the ability of users from various backgrounds to understand data, communicate results, and disseminate information across a wide range of disciplines. To support effective analysis of the dispersal of organisms at the landscape scale, we therefore designed Pydisp which is a free visual data analytics tool for spatiotemporal dispersal modeling built in Python. Its user interface allows users to perform a quick and interactive spatiotemporal analysis of species dispersal using bioecological and climatic data. Pydisp enables reuse and upgrade through the use of simple principles such as Fuzzy cellular automata algorithms. The potential of dispersal modeling is demonstrated in a case study by predicting the dispersal of Fopius arisanus (Sonan), endoparasitoids to control Bactrocera dorsalis (Hendel) (Diptera: Tephritidae) in Kenya. The results obtained from our example clearly illustrate the parasitoid's dispersal process at the landscape level and confirm that dynamic processes in an agroecosystem are better understood when designed using mechanistic modelling approaches. Furthermore, as demonstrated in the example, the built software is highly effective in portraying the dispersal of organisms despite the unavailability of detailed data on the species dispersal mechanisms.

Keywords: cellular automata, fuzzy logic, landscape, spatiotemporal

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59 Autophagy in the Midgut Epithelium of Spodoptera exigua Hübner (Lepidoptera: Noctuidae) Larvae Exposed to Various Cadmium Concentration - 6-Generational Exposure

Authors: Magdalena Maria Rost-Roszkowska, Alina Chachulska-Żymełka, Monika Tarnawska, Maria Augustyniak, Alina Kafel, Agnieszka Babczyńska

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Autophagy is a form of cell remodeling in which an internalization of organelles into vacuoles that are called autophagosomes occur. Autophagosomes are the targets of lysosomes, thus causing digestion of cytoplasmic components. Eventually, it can lead to the death of the entire cell. However, in response to several stress factors, e.g., starvation, heavy metals (e.g., cadmium) autophagy can also act as a pro-survival factor, protecting the cell against its death. The main aim of our studies was to check if the process of autophagy, which could appear in the midgut epithelium after Cd treatment, can be fixed during the following generations of insects. As a model animal, we chose the beet armyworm Spodoptera exigua Hübner (Lepidoptera: Noctuidae), a well-known polyphagous pest of many vegetable crops. We analyzed specimens at final larval stage (5th larval stage), due to its hyperfagy, resulting in great amount of cadmium assimilate. The culture consisted of two strains: a control strain (K) fed a standard diet, and a cadmium strain (Cd), fed on standard diet supplemented with cadmium (44 mg Cd per kg of dry weight of food) for 146 generations, both strains. In addition, the control insects were transferred to the Cd supplemented diet (5 mg Cd per kg of dry weight of food, 10 mg Cd per kg of dry weight of food, 20 mg Cd per kg of dry weight of food, 44 mg Cd per kg of dry weight of food). Therefore, we obtained Cd1, Cd2, Cd3 and KCd experimental groups. Autophagy has been examined using transmission electron microscope. During this process, degenerated organelles were surrounded by a membranous phagophore and enclosed in an autophagosome. Eventually, after the autophagosome fused with a lysosome, an autolysosome was formed and the process of the digestion of organelles began. During the 1st year of the experiment, we analyzed specimens of 6 generations in all the lines. The intensity of autophagy depends significantly on the generation, tissue and cadmium concentration in the insect rearing medium. In the Ist, IInd, IIIrd, IVth, Vth and VIth generation the intensity of autophagy in the midguts from cadmium-exposed strains decreased gradually according to the following order of strains: Cd1, Cd2, Cd3 and KCd. The higher amount of cells with autophagy was observed in Cd1 and Cd2. However, it was still higher than the percentage of cells with autophagy in the same tissues of the insects from the control and multigenerational cadmium strain. This may indicate that during 6-generational exposure to various Cd concentration, a preserved tolerance to cadmium was not maintained. The study has been financed by the National Science Centre Poland, grant no 2016/21/B/NZ8/00831.

Keywords: autophagy, cell death, digestive system, ultrastructure

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58 Effects of Dietary Polyunsaturated Fatty Acids and Beta Glucan on Maturity, Immunity and Fry Quality of Pabdah Catfish, Ompok pabda

Authors: Zakir Hossain, Md. Saddam Hossain

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A nutritionally balanced diet and selection of appropriate species are important criteria in aquaculture. The present study was conducted to evaluate the effects of polyunsaturated fatty acids (PUFAs) and beta glucan containing diet on growth performance, feed utilization, maturation, immunity, early embryonic and larval development of endangered Pabdah catfish, Ompok pabda. In this study, squid extracted lipids and mushroom powder were used as the source of PUFAs and beta glucan, respectively, and formulated two isonitrogenous diets such as basal or control (CON) diet and treated (PBG) diet with maintaining 30% protein levels. During the study period, similar physicochemical conditions of water such as temperature, pH, and dissolved oxygen (DO) were 26.5±2 °C, 7.4±0.2, and 6.7±0.5 ppm, respectively in each cistern. The results showed that final mean body weight, final mean length gain, food conversion ratio (FCR), specific growth rate (SGR), food conversion efficiency (%), hepatosomatic index (HSI), kidney index (KI), and viscerosomatic index (VSI) were significantly (P<0.01 and P<0.05) higher in fish fed the PBG diet than that of fish fed the CON diet. The length-weight relationship and relative condition factor (K) of O. pabda were significantly (P<0.05) affected by the PBG diet. The gonadosomatic index (GSI), sperm viability, blood serum calcium ion concentrations (Ca²⁺), and vitellogenin level were significantly (P<0.05) higher in fish fed the PBG diet than that of fish fed the CON diet; which was used to the indication of fish maturation. During the spawning season, lipid granules and normal morphological structure were observed in the treated fish liver, whereas fewer lipid granules of liver were observed in the control group. Based on the immunity and stress resistance-related parameters such as hematological indices, antioxidant activity, lysozyme level, respiratory burst activity, blood reactive oxygen species (ROS), complement activity (ACH50 assay), specific IgM, brain AChE, plasma PGOT, and PGPT enzyme activity were significantly (P<0.01 and P<0.05) higher in fish fed the PBG diet than that of fish fed the CON diet. The fecundity, fertilization rate (92.23±2.69%), hatching rate (87.43±2.17 %) and survival (76.62±0.82%) of offspring were significantly higher (P˂0.05) in the PBG diet than in the control. Consequently, early embryonic and larval development was better in PBG treated group than in the control. Therefore, the present study showed that the polyunsaturated fatty acids (PUFAs) and beta glucan enriched experimental diet were more effective and achieved better growth, feed utilization, maturation, immunity, and spawning performances of O. pabda.

Keywords: polyunsaturated fatty acids, beta glucan, maturity, immunity, catfish

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57 The Impact of Three Different Insecticides Against Fall Armyworms on Maize Productivity, in Somalia

Authors: Ahmed Ali Hassan

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The fall armyworm (FAW) was first identified in 2016 in Africa. FAW is widely distributed in Somalia and severely damages the maize crop. The effect of three different pesticides used to control the autumn armyworm, Spodoptera frugiperda (Noctuidae: Lepidoptera), on maize productivity was investigated in this study. During the 2020–2021 growing season, three insecticides (Malathion 57 EC, Ampligo150 ZC, and Carbryle 85 WP) were evaluated at field demonstration plots. Our result showed that significant mortality of S. frugiperda was observed on the treatment plot treated with Amplico. After spraying, Ampligo resulted in (92.200%) larval death. Compared to Carbaryl, which was less active and only caused 36.367% mortality after application, Malathion had a moderate mortality rate of 53.733%. Consequently, our current finding shows that the three selected insecticides reduced the damage and infestation level of S. frugiperda in the maize field conditions, and the most effective treatment was Amplico.

Keywords: maize, fall armyworm, insecticides, mortality

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56 Evaluation of the Most Effective Insecticides against the Spodoptera Frugiperda, on the Maize Production

Authors: Ahmed Ali Hassan

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In 2016, the Fall Armyworm (FAW) was first discovered in Africa. FAW is abundantly present in Somalia and seriously harms the maize crop. This investigation examined the impact on maize productivity of three different pesticides used to combat the autumn armyworm, Spodoptera frugiperda (Noctuidae: Lepidoptera). During the 2020–2021 growing season, three insecticides (Malathion 57 EC, Ampligo150 ZC, and Carbryle 85 WP) were evaluated at field demonstration plots. Our result showed that, significant mortality of S. frugiperda was observed on the treatment plot treated with Amplico. Ampligo caused over 90% larval mortality after application. Malathion had moderate activity, causing 53.733% mortality after application, while Carbaryl was less effective, causing 36.367% mortality after application. Consequently, the current finding shows that the three selected insecticides reduced the damage and infestation level of S. frugiperda in the maize field conditions and the most effective treatment were Amplico.

Keywords: pesticides, maize fall army worm, insecticides, mortality, S. frugiperda

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55 Tetraploid Induction in the Yellowtail Tetra Astyanax altiparanae

Authors: Nivaldo Ferreira do Nascimento, Matheus Pereira-Santos, Nycolas Levy-Pereira, José Augusto Senhorini, George Shigueki Yasui, Laura Satiko Okada Nakaghi

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Tetraploid individuals, which could produce diploid gametes, can be used for production of 100% triploid fish. Therefore, the aim of this study was to develop a tetraploidization protocol for A. altiparanae. We tested the effect of heat shock (40 °C; 2 min) at 16, 18, 20, 22, 24 and 26 minutes post fertilization (mpf). Untreated eggs were used as control. After hatching, ploidy status of the larvae was checked by flow cytometry. No difference were observed for the hatching rate between all treatments (P = 0.5974). However, we observed an increase in the larval abnormality in the heat shock treatments, in special at 22 (82.17 ± 6.66%) 24 (78.31 ±7.28%) and 26 mpf (79.01 ± 7.85%) in comparison with the control group (12.87 ± 4.46%). No tetraploid was observed at 16 and 18 mpf. The higher number of tetraploid individuals (52/55) was observed at 26 mpf. Our results showed that high percentages of tetraploids are obtained by heat shock (40°C; 2min) at 26 mpf, which could enable the mass production of triploid individuals in A. altiparanae.

Keywords: chromosome manipulation, polyploidy, flow cytometry, tetraploidization

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54 Toxic Activity of Biopesticide Metarhizium anisopliae var acridium ‘Green Muscle’ on the Cuticle of the Desert Locust Schistocerca gegaria (Forskål, 1775)

Authors: F. Haddadj, F. Acheuk, S. Hamdi, S. Zenia, A. Smai, H. Saadi, B. Doumandji-Mitiche

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Locust is causing significant losses in agricultural production in the countries concerned by the invasion. Up to the present control strategy has consisted only of the spreaders chemicals; they have proven harmful to the environment and taking a conscience prompted researchers and institutions to lean towards the biological control based mostly by using microorganism. It is in that sense is we've made our contribution by the use of a biopesticide which is entomopathogenic fungus Metarhizium anisopliae var acridium ‘Green Muscle’ on part of the cuticle the larval of fifth instar locust Schistocerca gregaria. Preliminary test on the study of the pathogenicity of the bio-control agent, was conducted in the laboratory on L5 S. gregaria, on which we inoculated treatment by direct spraying of the cuticle, 5 days after treatment individuals are sacrificed. Microscopic observation revealed alterations in the architecture of the cuticle which leads to disorganization of cell layers.

Keywords: biopesticide, cuticle, desert locust, effect

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53 Defense Priming from Egg to Larvae in Litopenaeus vannamei with Non-Pathogenic and Pathogenic Bacteria Strains

Authors: Angelica Alvarez-Lee, Sergio Martinez-Diaz, Jose Luis Garcia-Corona, Humberto Lanz-Mendoza

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World aquaculture is always looking for improvements to achieve productions with high yields avoiding the infection by pathogenic agents. The best way to achieve this is to know the biological model to create alternative treatments that could be applied in the hatcheries, which results in greater economic gains and improvements in human public health. In the last decade, immunomodulation in shrimp culture with probiotics, organic acids and different carbon sources has gained great interest, mainly in larval and juvenile stages. Immune priming is associated with a strong protective effect against a later pathogen challenge. This work provides another perspective about immunostimulation from spawning until hatching. The stimulation happens during development embryos and generates resistance to infection by pathogenic bacteria. Massive spawnings of white shrimp L. vannamei were obtained and placed in experimental units with 700 mL of sterile seawater at 30 °C, salinity of 28 ppm and continuous aeration at a density of 8 embryos.mL⁻¹. The immunostimulating effect of three death strains of non-pathogenic bacterial (Escherichia coli, Staphylococcus aureus and Bacillus subtilis) and a pathogenic strain for white shrimp (Vibrio parahaemolyticus) was evaluated. The strains killed by heat were adjusted to O.D. 0.5, at A 600 nm, and directly added to the seawater of each unit at a ratio of 1/100 (v/v). A control group of embryos without inoculum of dead bacteria was kept under the same physicochemical conditions as the rest of the treatments throughout the experiment and used as reference. The duration of the stimulus was 12 hours, then, the larvae that hatched were collected, counted and transferred to a new experimental unit (same physicochemical conditions but at a salinity of 28 ppm) to carry out a challenge of infection against the pathogen V. parahaemolyticus, adding directly to seawater an amount 1/100 (v/v) of the live strain adjusted to an OD 0.5; at A 600 nm. Subsequently, 24 hrs after infection, nauplii survival was evaluated. The results of this work shows that, after 24 hrs, the hatching rates of immunostimulated shrimp embryos with the dead strains of B. subtillis and V. parahaemolyticus are significantly higher compared to the rest of the treatments and the control. Furthermore, survival of L. vanammei after a challenge of infection of 24 hrs against the live strain of V. parahaemolyticus is greater (P < 0.05) in the larvae immunostimulated during the embryonic development with the dead strains B. subtillis and V. parahaemolyticus, followed by those that were treated with E. coli. In summary superficial antigens can stimulate the development cells to promote hatching and can have normal development in agreeing with the optical observations, plus exist a differential response effect between each treatment post-infection. This research provides evidence of the immunostimulant effect of death pathogenic and non-pathogenic bacterial strains in the rate of hatching and oversight of shrimp L. vannamei during embryonic and larval development. This research continues evaluating the effect of these death strains on the expression of genes related to the defense priming in larvae of L. vannamei that come from massive spawning in hatcheries before and after the infection challenge against V. parahaemolyticus.

Keywords: immunostimulation, L. vannamei, hatching, survival

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52 A Risk Assessment for the Small Hive Beetle Based on Meteorological Standard Measurements

Authors: J. Junk, M. Eickermann

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The Small Hive Beetle, Aethina tumida (Coleoptera: Nitidulidae) is a parasite for honey bee colonies, Apis mellifera, and was recently introduced to the European continent, accidentally. Based on the literature, a model was developed by using regional meteorological variables (daily values of minimum, maximum and mean air temperature as well as mean soil temperature at 50 mm depth) to calculate the time-point of hive invasion by A. tumida in springtime, the development duration of pupae as well as the number of generations of A. tumida per year. Luxembourg was used as a test region for our model for 2005 to 2013. The model output indicates a successful surviving of the Small Hive Beetle in Luxembourg with two up to three generations per year. Additionally, based on our meteorological data sets a first migration of SHB to apiaries can be expected from mid of March up to April. Our approach can be transferred easily to other countries to estimate the risk potential for a successful introduction and spreading of A. tumida in Western Europe.

Keywords: Aethina tumida, air temperature, larval development, soil temperature

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51 An Analytical View to the Habitat Strategies of the Butterfly-Like Insects (Neuroptera: Ascalaphidae)

Authors: Hakan Bozdoğan

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The goal of this paper is to evaluate the species richness, diversity and structure of in different habitats in the Kahramanmaraş Province in Turkey by using a mathematical program called as Geo-Gebra Software. The Ascalaphidae family comprises the most visually remarkable members of the order Neuroptera due to large dimensions, aerial predatory behaviour and dragonfly-like (or even butterfly-like) habits, allowing an immediate recognition also for occasional observers. Otherwise, they are one of the more poorly known families of the order in respect to biology, ecology and especially larval morphology. This discrepancy appears particularly noteworthy considering that it is a fairly large family (ca. 430 species) widely distributed in tropical and temperate areas of the World. The use of Dynamic Geometry, Analytical Softwares provides researchers a great way of visualising mathematical objects and encourage them to carry out tasks to interact with such objects and add to support of their researching. In this study we implemented; Circle with Center Through Point, Perpendicular Line, Vectors and Rays, Segments and Locus to elucidate the ecological and habitat behaviours of Butterfly-like lacewings in an analytical plane by using Geo-Gebra.

Keywords: neuroptera, Ascalaphidae, geo-gebra software, habitat selectivity

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50 Elongation Factor 1 Alpha Molecular Phylogenetic Analysis for Anastrepha fraterculus Complex

Authors: Pratibha Srivastava, Ayyamperumal Jeyaprakash, Gary Steck

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Exotic, invasive tephritid fruit flies (Diptera: Tephritidae) are a major concern to fruit and vegetable production in the USA. Timely detection and identification of these agricultural pests facilitate the possibility of eradication from newly invaded areas. They spread primarily as larvae in infested fruits carried in commerce or personal baggage. Identification of larval stages to species level is difficult but necessary to determine pest loads and their pathways into the USA. The main focus of this study is the New World genus, Anastrepha. Many of its constituent taxa are pests of major economic importance. This study is significant for national quarantine use, as morphological diagnostics to separate larvae of the various members remain poorly developed. Elongation factor 1 alpha sequences were amplified from Anastrepha fraterculus specimens collected from South America (Ecuador and Peru). Phylogenetic analysis was performed to characterize the Anastrepha fraterculus complex at a molecular level.

Keywords: anastrepha, diptera, elongation factor, fruit fly

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49 Differential Expression Analysis of Busseola fusca Larval Transcriptome in Response to Cry1Ab Toxin Challenge

Authors: Bianca Peterson, Tomasz J. Sańko, Carlos C. Bezuidenhout, Johnnie Van Den Berg

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Busseola fusca (Fuller) (Lepidoptera: Noctuidae), the maize stem borer, is a major pest in sub-Saharan Africa. It causes economic damage to maize and sorghum crops and has evolved non-recessive resistance to genetically modified (GM) maize expressing the Cry1Ab insecticidal toxin. Since B. fusca is a non-model organism, very little genomic information is publicly available, and is limited to some cytochrome c oxidase I, cytochrome b, and microsatellite data. The biology of B. fusca is well-described, but still poorly understood. This, in combination with its larval-specific behavior, may pose problems for limiting the spread of current resistant B. fusca populations or preventing resistance evolution in other susceptible populations. As part of on-going research into resistance evolution, B. fusca larvae were collected from Bt and non-Bt maize in South Africa, followed by RNA isolation (15 specimens) and sequencing on the Illumina HiSeq 2500 platform. Quality of reads was assessed with FastQC, after which Trimmomatic was used to trim adapters and remove low quality, short reads. Trinity was used for the de novo assembly, whereas TransRate was used for assembly quality assessment. Transcript identification employed BLAST (BLASTn, BLASTp, and tBLASTx comparisons), for which two libraries (nucleotide and protein) were created from 3.27 million lepidopteran sequences. Several transcripts that have previously been implicated in Cry toxin resistance was identified for B. fusca. These included aminopeptidase N, cadherin, alkaline phosphatase, ATP-binding cassette transporter proteins, and mitogen-activated protein kinase. MEGA7 was used to align these transcripts to reference sequences from Lepidoptera to detect mutations that might potentially be contributing to Cry toxin resistance in this pest. RSEM and Bioconductor were used to perform differential gene expression analysis on groups of B. fusca larvae challenged and unchallenged with the Cry1Ab toxin. Pairwise expression comparisons of transcripts that were at least 16-fold expressed at a false-discovery corrected statistical significance (p) ≤ 0.001 were extracted and visualized in a hierarchically clustered heatmap using R. A total of 329,194 transcripts with an N50 of 1,019 bp were generated from the over 167.5 million high-quality paired-end reads. Furthermore, 110 transcripts were over 10 kbp long, of which the largest one was 29,395 bp. BLAST comparisons resulted in identification of 157,099 (47.72%) transcripts, among which only 3,718 (2.37%) were identified as Cry toxin receptors from lepidopteran insects. According to transcript expression profiles, transcripts were grouped into three subclusters according to the similarity of their expression patterns. Several immune-related transcripts (pathogen recognition receptors, antimicrobial peptides, and inhibitors) were up-regulated in the larvae feeding on Bt maize, indicating an enhanced immune status in response to toxin exposure. Above all, extremely up-regulated arylphorin genes suggest that enhanced epithelial healing is one of the resistance mechanisms employed by B. fusca larvae against the Cry1Ab toxin. This study is the first to provide a resource base and some insights into a potential mechanism of Cry1Ab toxin resistance in B. fusca. Transcriptomic data generated in this study allows identification of genes that can be targeted by biotechnological improvements of GM crops.

Keywords: epithelial healing, Lepidoptera, resistance, transcriptome

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48 Impact of Ocean Acidification on Gene Expression Dynamics during Development of the Sea Urchin Species Heliocidaris erythrogramma

Authors: Hannah R. Devens, Phillip L. Davidson, Dione Deaker, Kathryn E. Smith, Gregory A. Wray, Maria Byrne

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Marine invertebrate species with calcifying larvae are especially vulnerable to ocean acidification (OA) caused by rising atmospheric CO₂ levels. Acidic conditions can delay development, suppress metabolism, and decrease the availability of carbonate ions in the ocean environment for skeletogenesis. These stresses often result in increased larval mortality, which may lead to significant ecological consequences including alterations to the larval settlement, population distribution, and genetic connectivity. Importantly, many of these physiological and developmental effects are caused by genetic and molecular level changes. Although many studies have examined the effect of near-future oceanic pH levels on gene expression in marine invertebrates, little is known about the impact of OA on gene expression in a developmental context. Here, we performed mRNA-sequencing to investigate the impact of environmental acidity on gene expression across three developmental stages in the sea urchin Heliocidaris erythrogramma. We collected RNA from gastrula, early larva, and 1-day post-metamorphic juvenile sea urchins cultured at present-day and predicted future oceanic pH levels (pH 8.1 and 7.7, respectively). We assembled an annotated reference transcriptome encompassing development from egg to ten days post-metamorphosis by combining these data with datasets from two previous developmental transcriptomic studies of H. erythrogramma. Differential gene expression and time course analyses between pH conditions revealed significant alterations to developmental transcription that are potentially associated with pH stress. Consistent with previous investigations, genes involved in biomineralization and ion transport were significantly upregulated under acidic conditions. Differences in gene expression between the two pH conditions became more pronounced post-metamorphosis, suggesting a development-dependent effect of OA on gene expression. Furthermore, many differences in gene expression later in development appeared to be a result of broad downregulation at pH 7.7: of 539 genes differentially expressed at the juvenile stage, 519 of these were lower in the acidic condition. Time course comparisons between pH 8.1 and 7.7 samples also demonstrated over 500 genes were more lowly expressed in pH 7.7 samples throughout development. Of the genes exhibiting stage-dependent expression level changes, over 15% of these diverged from the expected temporal pattern of expression in the acidic condition. Through these analyses, we identify novel candidate genes involved in development, metabolism, and transcriptional regulation that are possibly affected by pH stress. Our results demonstrate that pH stress significantly alters gene expression dynamics throughout development. A large number of genes differentially expressed between pH conditions in juveniles relative to earlier stages may be attributed to the effects of acidity on transcriptional regulation, as a greater proportion of mRNA at this later stage has been nascent transcribed rather than maternally loaded. Also, the overall downregulation of many genes in the acidic condition suggests that OA-induced developmental delay manifests as suppressed mRNA expression, possibly from lower transcription rates or increased mRNA degradation in the acidic environment. Further studies will be necessary to determine in greater detail the extent of OA effects on early developing marine invertebrates.

Keywords: development, gene expression, ocean acidification, RNA-sequencing, sea urchins

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47 Spinal Hydatidosis: Therapeutic Management of 5 Cases

Authors: Ghoul Rachid Brahim, Trad Khodja Rafik

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Vertebral localization of the hydatid cyst is a severe form of bone hydatidosis, is a parasitic infection caused by the larval forms of the tapeworms Echinococcus granulosus, The disease is slowly remaining silent (a long incubation period) which may explain why this pathology is often discovered at the stage of neurological complications. The objective of this study is to recall the clinical and radiological aspects of this condition and the importance of early diagnosis and appropriate management. We report a study of 5 patients with vertebral hydatidosis, four men and one woman, four (04) patients operated in the emergency setting for spinal cord compression (decompression by wide laminectomy with evacuation of intra and extra canal vesicles).Albendazole-based medical treatment is instituted in all patients. Results: The evolution was favorable for three patients, the other two patients reoperated for a local recurrence. Conclusion: Vertebral hydatidosis is a rare condition with a poor prognosis due to the risk of neurological damage, the infiltrating nature of bone lesions, the frequency of relapses and therapeutic difficulties. The only curative method remains surgery, which must aim for complete and large excision of the lesions as if it were a “malignant tumour”.

Keywords: hydatidosis, Echinococcosis granulosus, hydatid cyst, spinal cord compression, laminectomy

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46 Infestations of Olive Fruit Fly, Bactrocera oleae (Rossi) (Diptera: Tephritidae), in Different Olive Cultivars in Çanakkale, Turkey

Authors: Hanife Genç

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The olive fruit fly, Bactrocera oleae (Rossi), is an economically important and endemic pest in olive (Oleae europae) orchards in Turkey. The aim of this study was to determine olive fruit fly infestation in different olive cultivars in the laboratory. Olive fly infested fruits were collected in Çanakkale province to establish wild fly population. After having reproductive olive fly colonies, 14 olive cultivars were tested in the controlled laboratory conditions, at 23±2 °C, 65% RH and 16:8 h (light: dark) photoperiod. The olive samples from 14 different olive cultivars were collected in October 2015, in Campus of Dardanos, Çanakkale Onsekiz Mart University. Observations were carried out detecting some biological parameters such as the number of oviposition stings, active infestation, total infestation, the number of pupae and the adult emergence. The results indicated that oviposition stings were not associated with pupal yield. A few pupae were found within olive fruits which were not able to exit. Screening of the varieties suggested that less susceptible cultivar to olive fruit fly attacks was Arbequin while Gemlik-2M 2/3 showed significant susceptibility. Ovipositional preference of olive fly females and the success of larval development in different olive varieties are crucial for establishing new olive orchards to prevent high olive fruit fly infestation.

Keywords: infestation, olive fruit fly, olive cultivars, oviposition sting

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45 The Development and Survival of Solea aegyptiaca Raised on Artemia franciscana Supplemented with Four Distinct Microalgae Species Cultivated on Two Sources of Seawater

Authors: Hanan Mohamed Khairy

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This study used two water sources (Eastern Harbour (EH) and MaxWell (MW)) to assess suitable water sources to enhance Solea aegyptiaca aquaculture from the larval to the juvenile stage. Initially, the nutritional value of four microalgae (Chlorella salina, Tetraselmis chuii, Nannochloropsis salina, and N. oculata) was evaluated in the two water sources. When compared to EH, MW with a high nitrate level increased the algal biomass and the biochemical makeup of all species. Among the species under investigation, MW-N. salina had the highest growth and biochemical contents. It also produced Artemia franciscana, which had much higher levels of arachidonic acid (ARA), eicosapentaenoic acid (EPA ), and docosahexaenoic acid (DHA) than EH. Secondly, from 10–48 days post-hatch at a density of 15 larvae/L, Artemia-enriched MW-N salina was employed to improve S. aegyptiaca quality in both water sources. When compared to the strain raised on EH, the MW-S. aegyptiaca showed a noteworthy rise in morphometric parameters, albino percentages, and the greatest concentrations of ARA, EPA, and DHA (35.9, 6.1, and 15.9 µg/g, respectively). According to the study, MW-S. aegyptiaca albinism is caused by a high dietary and ARA content. From microalgae to S. aegyptiaca, the quality of the entire food chain is greatly influenced by the seawater supply.

Keywords: albinism, Artemia franciscana, fatty acids, microalgae, seawater sources, Solea aegyptiaca

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44 The Application of Insects in Forensic Investigations

Authors: Shirin Jalili, Hadi Shirzad, Samaneh Nabavi, Somayeh Khanjani

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Forensic entomology is the science of study and analysis of insects evidences to aid in criminal investigation. Being aware of the distribution, biology, ecology and behavior of insects, which are founded at crime scene can provide information about when, where and how the crime has been committed. It has many application in criminal investigations. Its main use is estimation of the minimum time after death in suspicious death. The close association between insects and corpses and the use of insects in criminal investigations is the subject of forensic entomology. Because insects attack to the decomposing corpse and spawning on it from the initial stages. Forensic scientists can estimate the postmortem index by studying the insects population and the developing larval stages.In addition, toxicological and molecular studies of these insects can reveal the cause of death or even the identity of a victim. It also be used to detect drugs and poisons, and determination of incident location. Gathering robust entomological evidences is made possible for experts by recent Techniques. They can provide vital information about death, corpse movement or burial, submersion interval, time of decapitation, identification of specific sites of trauma, post-mortem artefacts on the body, use of drugs, linking a suspect to the scene of a crime, sexual molestations and the identification of suspects.

Keywords: Forensic entomology, post mortem interval, insects, larvae

Procedia PDF Downloads 502
43 Toxicity of Biopesticide Metarhizium anisopliae var acridium "Green Muscle" on the Cuticle of the Desert Locust Schistocerca gegaria (Forskål, 1775)

Authors: F. Haddadj, F. Acheuk, S. Hamdi, S. Zenia, A. Smai, H. Saadi, B. Doumandji-Mitiche

Abstract:

Locust is causing significant losses in agricultural production in the countries concerned by the invasion. Up to the present control strategy has consisted only of the spreaders chemicals; they have proven harmful to the environment and. For this, a new control method appeared it comes to the biological control based mostly by using microorganism. It is in that sense is we've made our contribution by the use of a biopesticide which is entomopathogenic fungus Metarhizium anisopliae var acridium "Green Muscle" on part of the cuticule the larval of fifth instar locust Schistocerca gregaria (Forskål, 1775). Preliminary test on the study of the pathogenicity of M. anisopliae var acridium biocontrol agent, was conducted in the laboratory on L5 S. gregaria, on which we inoculated treatment in the digestive tract and it administrant 20μl of entomopathogenic solution orally at a dose DL50 = 3.25 x107 sp./ ml (median lethal dose estimated at earlier), 5 days after treatment individuals are sacrificed. After dissection cuticles are recovered and then subjected to histological sections. The histological technique followed is that of Martoja Martoja-Pierson (1967). Microscopic observation revealed alterations in the architecture of the cuticule which leads to disorganization of cell layers.

Keywords: biopesticide, cuticle, desert locust, toxicity

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42 Studies on Population and Management of Melon Fruit Fly Bactrocera cucurbitae (Coquillett) in Vegetables Agro-Ecosystem in District Hyderabada

Authors: Abro Zain-Ul-Aabdin, Naheed Baloch, Khuhro Niaz Hussain, Waseem Akbar, Noor Abid Saeed

Abstract:

The Melon Fruit Fly Bactrocera cucurbitae (Coq.) belongs to family: Tephritidae order: Diptera and is distributed throughout the vegetable growing areas of Pakistan. The B. cucurbitae is injurious pest of more than 125 species of the vegetables throughout the world. In the present studies we investigated the population of this important pest in cucurbit crops and influence of abiotic parameters such as: temperature, relative humidity and rainfall. The study was carried out at two different locations of District, Hyderabad. The locations were Jeay Shah and Dehli farm where three cucurbit vegetable crops, such as bottle gourd (Lagenaria siceraria), bitter gourd (Momordica charantia) and ridge gourd (Luffa acutangula) were grown. The traps were baited with Cue-lure and deployed at three meter height in the all locations from 01.01.2015 and up to 30.06.2015. Results revealed that overall significantly higher (P < 0.05) population was recorded on L.acutangula, M.charantia and L.siceraria (130.64, 127.21, and 122.91), respectively. However, significantly higher (P < 0.05) population was observed on L. acutangula (339.4±22.59) during the 4th week of May 2015 followed by M. charantia (334.6±22.76) L. siceraria (333.2±20.13). Whereas; lowest population was recorded on L. siceraria (5.8±1.39) followed by L. acutangula and M. charantia (6.8±0.80g, 8.0±1.30) respectively during the 4th week of January. The population of B. cucurbitae was significantly correlated with the temperature while negatively correlated with relative humidity. Meanwhile in the parasitism preference experiment pupal parasitoid Dirhinus giffardii showed significantly higher (P<0.05) parasitization when the pupae of B.cucurbitae were reared on Cucumber (Cucumis sativus) (24.8±0.48) and also female were yielded from pupae reared on C.sativus under no choice experiment. Similarly higher parasitization and female were recovered when pupae were supplied C. sativus under free choice experiment. Results of the present investigation would be useful in developing a sustainable pest management strategy in the vegetable agro-ecosystem.

Keywords: Dirhinus giffardii, Bactrocera cucurbitae Cucumis sativus, diptera, free choice, parasitization

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41 Bio-Efficacy of Newer Insecticides against Diamondback Moth (Plutella xylostella L. ) in Cabbage

Authors: C. G. Sawant, C. S. Patil

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The investigation was conducted during January 2016 on Farmer’s field at Nandur Madhyameshwar, Tq. Niphad, Dist. Nashik (Maharashtra: India) on bio-efficacy of newer insecticides against Plutella xylostella L. infesting cabbage. The cabbage crop (var. Saint) was raised according to package of practices except for plant protection measures. Six newer insecticides along with two conventional insecticides and one synthetic pyrethroid were applied twice at 30 and 55 days after transplanting. Insecticidal solutions were diluted in water (375-500 L ha-1) and applied using knapsack sprayer (16L) with hollow cone nozzle. Treatments included indoxacarb @ 40 g a.i.ha-1, spinosad @ 17.5 g a.i.ha-1, flubendiamide @18.24 g a.i. ha-1, diafenthiuron @ 300 g a. i. ha-1, emamectin benzoate @ 10 g a. i. ha-1, chlorantraniliprole @ 10 g a. i. ha-1, quinalphos @ 250 g a. i. ha-1, triazophos @ 500 g a. i. ha-1, bifenthrin @ 50 g a.i. ha-1 and untreated control. The larvae were counted on head and outside the head. Observations were recorded one day before spray (Precount) and 1,3,7,14 days after spray. Results revealed that all the insecticidal treatments were significantly superior over untreated control by recording lower larval count. Among the insecticidal treatments, significantly lowest number of larvae of diamondback moth was recorded in chlorantraniliprole @ 10 g a.i.ha-1 (1.00 larvae plant-1) followed by spinosad @ 17.5 g a.i. ha-1 (1.45 larvae plant-1 and flubendiamide 18.24 g a.i. ha-1(1.53 larvae plant-1). The efficacy of insecticides reflected on yield of marketable cabbage heads by recording 242.27 qt ha-1 (1:33.38) in the treatment of chlorantraniliprole @ 10 g a.i.ha-1. It was followed by spinosad @ 17.5 g a.i. ha-1 with 236.91 qt ha-1 (1:24.92) and flubendiamide 18.24 g a.i. ha-1 with 228.49 qt ha-1 (1:30.43).

Keywords: bio-efficacy, cabbage, chlorantraniliprole, Plutella xylostella L.

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40 Zebrafish Larvae Model: A High Throughput Screening Tool to Study Autism

Authors: Shubham Dwivedi, Raghavender Medishetti, Rita Rani, Aarti Sevilimedu, Pushkar Kulkarni, Yogeeswari Perumal

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Autism Spectrum Disorder (ASD) is a complex neurodevelopmental disorder of early onset, characterized by impaired sociability, cognitive function and stereotypies. There is a significant urge to develop and establish new animal models with ASD-like characteristics for better understanding of underlying mechanisms. The aim of the present study was to develop a cost and time effective zebrafish model with quantifiable parameters to facilitate mechanistic studies as well as high-throughput screening of new molecules for autism. Zebrafish embryos were treated with valproic acid and a battery of behavioral tests (anxiety, inattentive behavior, irritability and social impairment) was performed on larvae at 7th day post fertilization, followed by study of molecular markers of autism. This model shows a significant behavioural impairment in valproic acid treated larvae in comparison to control which was again supported by alteration in few marker genes and proteins of autism. The model also shows a rescue of behavioural despair with positive control drugs. The model shows robust parameters to study behavior, molecular mechanism and drug screening approach in a single frame. Thus we postulate that our 7 days zebrafish larval model for autism can help in high throughput screening of new molecules on autism.

Keywords: autism, zebrafish, valproic acid, neurodevelopment, behavioral assay

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39 Parental Diet Effects on Offspring Body Size and Pathogen Resistance in Bactrocera tryoni

Authors: Hue Dinh, Binh Nguyen, Vivian Mendez, Phillip W. Taylor, Fleur Ponton

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Better understanding of how parental diet affects offspring traits is an important ecological and evolutionary question. In this study, we explored how maternal diet influences offspring physiology and resistance to infection using Bactrocera tryoni (Q-fly) as a system model. Female Q-flies were fed one of six single diets varying in their yeast-to-sugar ratio yielding six protein-to-carbohydrate ratios. As controls, we used females that were given a choice between yeast and sugar. Males were reared on a choice diet and allowed to mate with females 14 days post-emergence. Results showed that while maternal diet does not influence offspring developmental time, it has a strong effect on larval body weight. Mother fed either high-protein or high-sugar diet produced larger progeny. By challenging offspring with the bacterium Serratia marcescens, we found that female offspring from mothers fed high-sugar diet survived better the infection compared to those from mothers fed low-sugar diet. In contrast, male offspring produced by mother fed high-protein diet showed better resistance to the infection compared to those produced by mother fed low-protein diet. These results suggested sex-dependent transgenerational effects of maternal nutrition on offspring physiology and immunity.

Keywords: bacterial infection, Bactrocera tryoni, maternal diet, offspring, Serretia marcescens

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38 Impact of ‎Foliar ‎Formulations of Macro and Micro Nutrients on ‎the ‎Tritrophic Association of Wheat Aphid ‎and Entomophagous Insects

Authors: Muhammad Sufyan, Muhammad J. Arif, Muhammad Arshad, Usman Shoukat

Abstract:

In Pakistan, wheat (Triticum aestivum L.) is seriously attacked by the wheat ‎aphid. Naturally, bio control agents play an important role in managing wheat aphid. However, association ‎among pest, natural enemies and host plant is highly affected by food resource ‎concentration and predator/parasitoid factor of any ecosystem. The present ‎study was conducted to estimate the effect of different dose levels of macro ‎and micronutrients on the aphid population and its entomophagous insect ‎on wheat and their tri-trophic association. The experiment was laid out in ‎RCBD with six different combinations of macro and micronutrients and a control treatment. The data was initiated from the second week of ‎the February till the maturity of the crop. Data regarding aphid population and ‎coccinellids counts were collected on weekly basis and subjected to analysis of ‎variance and mean comparison. The data revealed that aphid ‎population was at peak in the last week of March. Coccinellids population ‎increased side by side with aphid population and declined after second week of ‎April. Aphid parasitism was maximum 25% on recommended dose of Double and ‎Flasher and minimum 8.67% on control treatment. Maximum aphid population was observed on first April with 687.2 specimens. However, this maximum population was shown against the application of Double + Flasher treatment. The minimum aphid population was recorded after the application of HiK Gold + Flasher recommended dose on 15th April. The coccinellids population was at peak level at on 8th April and against the treatment double recommended dose of HiK gold + Flasher. Amount of nitrogen, phosphorus and potassium percentage dry leaves ‎components was maximum (2.33, 0.18 and 2.62 % dry leaves. respectively) in ‎plots treated with recommended double dose mixture of Double + Flasher and ‎Hi-K Gold + Flasher while it was minimum (1.43, 0.12 and 1.77 dry leaves ‎respectively) in plots where no nutrients applied. The result revealed that maximum parasitism was at recommended level of micro and macro nutrients application.‎ Maximum micro nutrients zinc, copper, manganese, iron and boron found with values 46.67 ppm, 21.81 ppm, 62.35 ppm, 152.69 ppm and 36.78 respectively. The result also showed that Over application of macro and micro nutrients should be avoided because it do not help in pest control, conversely it may cause stress on plant. The treatment Double and Flasher recommended dose ratio is almost comparable with recommended dose and present studies confirm its usefulness on wheat.

Keywords: entomophagous insects, macro and micro nutrients, tri-trophic, wheat aphid

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37 Nuclear Mitochondrial Pseudogenes in Anastrepha fraterculus Complex

Authors: Pratibha Srivastava, Ayyamperumal Jeyaprakash, Gary Steck, Jason Stanley, Leroy Whilby

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Exotic, invasive tephritid fruit flies (Diptera: Tephritidae) are a major threat to fruit and vegetable industries in the United States. The establishment of pest fruit fly in the agricultural industries and produce severe ecological and economic impacts on agricultural diversification and trade. Detection and identification of these agricultural pests in a timely manner will facilitate the possibility of eradication from newly invaded areas. Identification of larval stages to species level is difficult, but is required to determine pest loads and their pathways into the United States. The aim of this study is the New World genus, Anastrepha which includes pests of major economic importance. Mitochondrial cytochrome c oxidase I (COI) gene sequences were amplified from Anastrepha fraterculus specimens collected from South America (Ecuador and Peru). Phylogenetic analysis was performed to characterize the Anastrepha fraterculus complex at a molecular level. During phylogenetics analysis numerous nuclear mitochondrial pseudogenes (numts) were discovered in different specimens. The numts are nonfunctional copies of the mtDNA present in the nucleus and are easily coamplified with the mitochondrial COI gene copy by using conserved universal primers. This is problematic for DNA Barcoding, which attempts to characterize all living organisms by using the COI gene. This study is significant for national quarantine use, as morphological diagnostics to separate larvae of the various members remain poorly developed.

Keywords: tephritid, Anastrepha fraterculus, COI, numts

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36 Comparative Study of the Abundance of Winter Nests of the Pine Processionary Caterpillar in Different Forests of Pinus Halepensis, pinus Pinaster, Pinus Pinea and Cedrus Atlantica, in Algeria

Authors: Boudjahem Ibtissem, Aouati Amel

Abstract:

Thaumetopoea pityocampa is one of the major insect pests of pine forests in Algeria, the Mediterranean region, and central Europe. This pest is responsible for several natural and human damages these last years. The caterpillar can feed itself during the larval stage on several species of pine or cedar. The forests attack by the insect can reduce their resistance against other forest enemies, fires, or drought conditions. In this case, the tree becomes more vulnerable to other pests. To understand the eating behavior of the insect in its ecological conditions, and its nutritional preference, we realized a study of the abundance of winter nests of the pine processionary caterpillar in four different forests: Pinus halepensis; Pinus pinaster; Pinus pinea, and Cedrus atlantica. A count of the sites affected by the processionary caterpillar was carried out on a hundred trees from the forests in different regions in Algeria; Alkala region, Mila region, Annaba region, and Blida region; the total rate and average abundance are calculated for each forest. Ecological parameters are also estimated for each infestation. The results indicated a higher rate of infestation in Pinus halepensis trees (85%) followed by Cedrus atlantica (66%) and Pinus pinaster (50%) trees. The Pinus pinea forest is the least attacked region by the pine processionary caterpillar (23%). The abundance of the pine processionary caterpillar can be influenced by the height of the trees, the climate of the region, the age of the forest but also the quality of needles.

Keywords: Thaumetopoea pityocampa, Pinus halepensis, needles, winter nests

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35 Metabolic Costs and Chemical Profiles of Wax Production in Cryptolaemus montrouzieri and Tenuisvalvae notata

Authors: Nataly De La Pava, Christian S. A. Silva-Torres, Arodí P. Favaris, José Maurício S. Bento

Abstract:

The lady beetles Tenuisvalve notata and Cryptolaemus montrouzieri are important predators of mealybugs (Hemiptera: Pseudococcidae). Similar to the prey, these lady beetles produce wax filaments that cover their body during the larval stage. It has been hypothesized that lady beetle body wax chemical profiles are similar to their prey as i) a mechanism of camouflage and ii) conveying protection to the lady beetle larvae against aphid-tending predatory ants. In this study, we tested those hypotheses for the predators T. notata and C. montrouzieri and two mealybug prey species, Ferissia dasyrilii, and Planococcus citri. Next, we evaluated the influence of feeding on cuticular chemistry during predator development and identified possible metabolic costs associated with wax production. Cuticular wax samples were analyzed by GC-MS and GC-FID. Also, the metabolic cost linked to wax production was evaluated in the 4th instar larvae of the two predators when subjected to body wax removal from 0 to 4 times. Results showed that predator body wax profiles are not similar to the chemical profile of prey body wax. There was a metabolic cost associated with wax removal; predators (male and female) showed a significant reduction in adult body weight when the wax was removed. This suggests the reallocation of energy to wax replacement instead of growth. In addition, it was detected effects of wax removal on fecundity and egg viability. The results do not support the hypothesis that predators mimic the cuticular wax composition of prey as a means of camouflage.

Keywords: biological control, body wax, coccinellids, cuticular hydrocarbons, metabolism cost, reproduction

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34 Ecological Investigations for the Control of Aedes aegypti (Diptera: Culicidae) in the Selected Study Districts of Punjab, Pakistan

Authors: Muhammad Sohail Sajid, Muhammad Abdullah Malik, Muhammad Saqib, Faiz Ahmad Raza, Waseem Akram

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Aedes (Ae.) aegypti, the vector of pathogens of one health significance, has gained currency over the last decade. The present study reports the prevalence of A. aegypti larvae in indoor and outdoor niches from the three districts of different agro-geo-climatic zones of Punjab, including Chakwal (north), Faisalabad (central), and Dera Ghazi Khan (south). Mosquito larvae were collected, preserved, and transferred for identification. The relevant data were collected on a predesigned questionnaire. Stegomyia indices, including House Index (HI), Breteau Index (BI), and Container Index (CI), were calculated. The association of different breeding containers with the prevalence of Ae. aegypti larvae were estimated through Chi-square analysis. The highest Stegomyia indices were calculated in Chakwal (HI = 46.61%, BI = 91.67%, and CI = 15.28%) as compared to Faisalabad (HI = 34.11%, BI = 68.75% and, CI = 13.04%) and DG Khan (HI = 28.39%, BI = 68.23% and, CI = 11.29%), respectively. Irrespective of the geographical area, earthen jars, water tanks, and tree holes were found to be significantly associated (p < 0.05) with the abundance of Ae. aegypti larvae. However, tires and plastic bottles in Faisalabad and DG Khan while flower tubs and plastic buckets in Faisalabad and Chakwal were found to be significantly associated (p < 0.05) with the larval abundance. The results are a maiden attempt to correlate the magnitude of Ae. aegypti larvae in various microclimatic niches of Punjab, Pakistan, which might help in policy-making for preventive management of the menace.

Keywords: Aedes aegypti, ecology, breeding habitats, Stegomyia indices, breeding containers

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33 Interspecific Competition among Three Fruit Fly Species Infesting Watermelon and Zucchini (Cucurbitaceae)

Authors: Gbenonsi A. Fabrice, Mama Sambo Sahadatou, Layode B. F. Rodolphe, Totin A. Felicien, Onzo Alexis, Karlsson M. Frida

Abstract:

Interspecific competition occurs among arthropod pest species that share hosts, thereby influencing their population dynamics. In sub-Saharan Africa, the native fruit fly species Dacus vertebratus (Bezzi) and Dacus ciliatus (Loew) (Diptera: Tephritidae) and the exotic Zeugodacus cucurbitae (Coquillett) are concurrent pests in the same host fruits; hence competition among them is likely to occur. We explored interspecific competition among these three fruit fly species on zucchini (Cucurbita pepo L.) and watermelon (Citrullus lanatus Thunb) (Cucurbitaceae) to improve our understanding of the interaction between the species and their capacity to coexist. We exposed the vegetable fruits to different densities of fruit fly species and studied their behavioural activities, evaluating the extrinsic competition. To assess intrinsic competition and understand the effect of co-occurrence inside the fruits, eggs of the three fruit flies were pairwise inoculated into the same fruits. Results showed that the behaviour on the fruits differed between the species and that the interspecific competition affected their developmental time and larval survival in both watermelon and zucchini. Z. cucurbitae were more aggressive than the other species and managed to oviposit more frequently. Emergence was reduced for D. ciliatus and D. vertebratus when inoculated together with Z. cucurbitae in watermelon but not in zucchini. Physical confrontations were more common in zucchini than in watermelon and were more frequently won by Z. cucurbitae than D. vertebratus and D. ciliatus. Interspecific competition information obtained about behavioural differences and interaction effects, providing background for explaining the present fruit fly guild on certain Cucurbitaceae fruits in West Africa.

Keywords: behavioural activities, extrinsic competition, intrinsic competition, Tephritidae

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32 Sex-Dependent Fitness Improvement of Hercules Beetle Larvae by Amendment of Thermophile-Fermented Compost to Humus

Authors: Futo Asano, Yusuke Yatsushiro, Hirokuni Miyamoto, Hiroaki Kodama

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A thermophile-fermented compost is produced using small fishes, crabs, and shrimps under a high temperature (approximately 75℃) by fermentation-associated self-heating. This compost has been used as a feed additive for pigs and hens in Japan, and the fecundity of this livestock is enhanced. Firmicutes is a dominant phylum in the microbial composition of the compost. We first reported that improvement of female larval fitness of Hercules beetle can be achieved by amendment of this compost to the humus. When the 90-d-old larvae were reared for subsequent 72 days in the humus with this compost, the growth of female larvae was significantly enhanced when compared with the growth of female larvae in the humus without the compost. In contrast, the growth of male larvae in the compost-free humus was the same as the larvae grow in the compost-amended humus. The bacterial composition of the feces of larvae was determined at 0 days and 46 days after transfer to the humus with or without the compost. The most dominant bacterium in the feces was Xylanimonas. Interestingly, the growth improvement of female larvae was associated with an increased abundance of Mollicutes in the fecal samples. These results indicate that the compost act as a probiotic material for enhancing the female larvae growth by supporting Mollicutes. Here, we tried to isolate Mollicutes from the contents of the midgut and hindgut of the 3rd instar female larvae of the Hercules beetle. These gut contents were spread onto a selective agar medium for Mollicutes (PPLO agar broth, BD Difco, NJ, USA). Although we isolated none of the Mollicutes until now, several bacteria that are closely related to Xylanimonas and Luteimicrobium were isolated. These isolates have xylanase and glucanase (CMCase) activities. We show the gut bacterial profiles of larvae and discuss how the fitness of female larvae of the Hercules beetle is improved by the compost.

Keywords: compost, beetle, mollicutes, woody biomass

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31 Impact of Mixed Prey Population on Predation Potential and Food Preference of a Predaceous Ladybird, Coccinella septempunctata

Authors: Ahmad Pervez

Abstract:

We investigated predation potential and food preference of different life stages of a predaceous ladybird Coccinella septempunctata L. (Coleptera: Coccinellidae) using a nutritive food (mustard aphid, Lipaphis erysimi) and a toxic food (cabbage aphid, Brevicoryne brassicae). We gave monotypic prey, L. erysimi, then B. brassicae to all life stages and found that second, third and fourth instars and adult female C. septempunctata daily consumed greater number of former prey. However, the first instar and the adult male equally consumed both the prey. In choice condition, each larva, adult male and female consumed mixed aphid diet separately in three proportions (i.e. low: high, equal: equal and high: low densities of L. erysimi: B. brassicae). We hypothesized that life stages of C. septempunctata will prefer L. erysimi regardless of its proportions. Laboratory experiment supported this hypothesis only at the adult level showing high values of β and C preference indices. However, it rejects this hypothesis at the larval level, as larvae preferred B. brassicae in certain combinations and showed no preference in a few combinations. We infer that mixing of nutritive diet in a toxic diet may possibly overcome the probable nutritive deficiency and/or reduces the toxicity of toxic diet, especially to the larvae of C. septempunctata. Consumption of high proportion of B. brassicae mixed with fewer L. erysimi suggests that mixed diet could be better for the development of immature stages of C. septempunctata.

Keywords: Coccinella septempunctata, predatory potential, prey preference, Lipaphis erysimi, Brevicoryne brassicae

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