Showing papers in "Entomological Research in 2018"
TL;DR: The results indicate that the exuvium and whole body of T. molitor larva may serve as a source of chitin and chitosan for use in domestic animal feed.
Abstract: The purpose of this study was to investigate the production of chitin and chitosan from both the exuvium and whole body of mealworm (Tenebrio molitor) larvae. Chitin from the exuvium and whole body of T. molitor larvae was chemically extracted with acid and alkali solutions to achieve demineralization (DM) and deproteinization (DP), respectively. The average DM (%) and DP (%) on a dry weight (DW) basis was 32.56 and 73.16% from larval exuvium, and 41.68 and 91.53% from whole body, respectively. To obtain chitosan, chitin particles from the exuvium and whole body of T. molitor larva were heated at various temperatures in different concentrations of NaOH. Average chitin yields were 18.01% and 4.92% of DW from the exuvium and whole body, respectively. The relative average yield of chitosan from whole body was 3.65% of DW. On average, over 90% of chitosan derived from whole body was deacetylated. The viscosity of chitosan from whole body was ranged from 48.0 cP to 54.0 cP. The chitin content of dry and wet byproducts from whole body were 17.32% and 16.94% respectively, compared to dry weight. The chitosan contents of byproducts on a DW basis were 14.48% in dry and 13.07% in wet byproduct. These results indicate that the exuvium and whole body of T. molitor larva may serve as a source of chitin and chitosan for use in domestic animal feed.
58 citations
TL;DR: A potential distribution of red imported fire ant is provided that is necessary to establish a proper quarantine plan for their management to minimize adverse impacts of climate change.
Abstract: The red imported fire ant is considered one of the most notorious invasive species because of its adverse impact on both humans and ecosystems. Public concern regarding red imported fire ants has been increasing, as they have been found seven times in South Korea. Even if red imported fire ants are not yet colonized in South Korea, a proper quarantine plan is necessary to prevent their widespread distribution. As a basis for quarantine planning, we modeled the potential distribution of the red imported fire ant under current climate conditions using six different species distribution models (SDMs) and then selected the random forest (RF) model for modeling the potential distribution under climate change. We acquired occurrence data from the Global Biodiversity Information Facility (GBIF) and bioclimatic data from WorldClim. We modeled at the global scale to project the potential distribution under the current climate and then applied models at the local scale to project the potential distribution of the red imported fire ant under climate change. Modeled results successfully represent the current distribution of red imported fire ants. The potential distribution area for red imported fire ants increased to include major harbors and airports in South Korea under the climate change scenario (RCP 8.5). Thus, we are able to provide a potential distribution of red imported fire ant that is necessary to establish a proper quarantine plan for their management to minimize adverse impacts of climate change.
43 citations
TL;DR: It is suggested that WM might prove to be a promising alternative to FM in practical diets for juvenile rockfish and could be used at an inclusion level of up to 32% without having any adverse consequences for the health and performance of the fish.
Abstract: An 8‐week feeding trial was designed to evaluate the potential of yellow mealworm (Tenebrio molitor) as a locally available nutrient‐rich feedstuff for juvenile rockfish (Sebastes schlegeli). Experimental diets containing elevated levels of mealworm meal (WM) supplemented with synthetic methionine were formulated to be isonitrogenous, isolipidic and isoenergetic to a WM‐free fishmeal (FM) based control diet (designated as WM0, WM8, WM16, WM24 and WM32, respectively). To determine the necessity of dietary methionine supplementation at the highest inclusion of WM, a diet was prepared to contain 32% WM without methionine supplementation (WM32‐AA). Triplicate groups of rockfish juveniles (Mean ± S.E.; 3.11 ± 0.01 g) were fed one of the experimental diets to apparent satiation twice daily for 8 weeks. Fish growth performance in terms of weight gain and specific growth rate increased with increasing dietary inclusion of WM from 0 to 16% and then tended to decrease with further increase in dietary WM levels to 32%. Protein retention (PR) values followed the same trend as growth rates with the highest values found in fish offered WM16 diet. Although fish fed WM32‐AA diet showed significantly lower growth rate and PR values compared to those fed WM16 diet, their performance was still comparable to that of the WM‐free control group. Plasma triglyceride level was negatively affected by dietary WM inclusion and the lowest values were observed in the WM32‐AA group. Whole‐body and fillet proximate and essential amino acid compositions were not altered by dietary treatment and these values were comparable to those of the WM0 group. These findings suggested that WM might prove to be a promising alternative to FM in practical diets for juvenile rockfish and could be used at an inclusion level of up to 32% without having any adverse consequences for the health and performance of the fish. Although the diet containing 32% WM seemed to support a performance similar to that of the control diet, the recommended dietary inclusion level was no more than 16% of the diet dry matter.
28 citations
TL;DR: The larvae fed on flavonoid‐treated diets showed significant reduction in serine protease, trypsin and esterase activities, and can be utilized in insect control programs.
Abstract: The effect of various flavonoids, lectins and phenyl β-D-glucoside on larval survival, weights and the activities of digestive (total serine protease and trypsin) and detoxifying (esterase and glutathione-S-transferase) enzymes of Spodoptera litura larvae at 7 days after treatment was studied through diet incorporation assay. Flavonoids (rutin, chlorogenic acid, quinic acid, caffeic acid, naringenin, quercitin, kaempferol, myricetin, catechin, and ferulic acid) were incorporated in artificial diet at 100, 500 and 1000 ppm, lectins: groundnut leaf lectin (GLL), concavalin A (ConA) and phenyl β-D-glucoside at 1, 2 and 5 μg/mL. Flavonoids such as rutin, quercitin and kaempferol at 1000 ppm were more toxic to S. litura larvae than quinic acid, caffeic acid, naringenin, myricetin, catechin, and ferulic acid. Larval growth and development were significantly reduced in S. litura larvae fed on a diet with GLL and ConA at 5 μg/mL compared to the larvae fed at 2 and 1 μg/mL concentrations. The larvae fed on flavonoid-treated diets showed significant reduction in serine protease, trypsin and esterase activities. The flavonoids such as rutin, chlorogenic acid, quinic acid, naringenin, quercitin, kaempferol and myricetin, and lectins, GLL and ConA can be utilized in insect control programs.
24 citations
TL;DR: This study demonstrates that the fatty acid composition in R. differens can be influenced through diet, and with dietary manipulations, using local plants in Africa, it is possible to produce R. differencens with preferred high quality essential fatty acids for human consumption.
Abstract: Ruspolia differens (Serville) (Orthoptera: Tettigoniidae) is a highly valued edible grasshopper species in Africa. However, the effects of plant diets on lipid content and fatty acid composition of R. differens are not well understood. We tested the effects of four diets on the total lipid content and fatty acid composition of R. differens. Sixth instar nymphs of R. differens were reared on one, and mixtures of two, three, and six natural plant inflorescences. Individuals collected from the field constituted a control treatment. We extracted lipids and analyzed the fatty acid methyl esters using gas chromatography–mass spectrometry. We analyzed if the total lipid content, body weight, and fatty acid composition differed among diets and between the sexes using two‐way ANOVAs and a PERMANOVA model, respectively. The total lipid content and weight of R. differens did not differ among the diets. The nine common fatty acids were palmitic (mean across treatments, 26%), oleic (22%), palmitoleic (18%), linoleic (13%), stearic (7%), myristic (6%), myristoleic (4%), α‐linolenic (2%) and arachidic acid (1%). The composition of fatty acids and the proportion of essential fatty acids significantly differed among the diets. The proportion of essential fatty acids was highest in the control treatment (21%) but low in less diversified (one to three feed) diets (12–13%). This study demonstrates that the fatty acid composition in R. differens can be influenced through diet. Thus, with dietary manipulations, using local plants in Africa, it is possible to produce R. differens with preferred high quality essential fatty acids for human consumption.
23 citations
TL;DR: The results suggest that the activation of the humoral immunity induced by immunization functioned to enhance the production of antibacterial peptides from the insect and their antibacterial properties.
Abstract: There is a need to discover new therapeutic substances due to the emergence of deadly infectious diseases and various antibiotic resistance. We focused on the larvae that are utilized as a medical insect for the treatment of skin damage in Europe and America. This study was to investigate the pharmacological activities of novel antibacterial peptides isolated from Hermetia illucens larvae against the Klebsiella pneumoniae and Shigella dysenteriae. The larvae were immunized by probiotics (Lactobacillus casei) for 24 h. The hemolymph from the immunized larvae was fractionated through reverse-phase chromatography. Peptides were purified using HPLC and the coomassie blue staining, and identified using Nano-LC-ESI-MS/MS system. Antibacterial activities of the peptides were evaluated by turbidometric assay, liquid broth dilution assay, resazurin assay, and agar disk diffusion method. The minimum inhibitory concentrations (MICs) of the peptides were measured as 150 μg/mL through the turbidometric, liquid broth dilution, and resazurin assays. The peptides effectively inhibited their growth/proliferation as well as the survival rate of the tested bacteria. Furthermore, the immunized larvae exhibited overexpression of the peptides compared to non-immunized larvae. These results demonstrate that the peptides induced by H. illucens exert strong antibacterial activity against Gram-negative bacteria. The results suggest that the activation of the humoral immunity induced by immunization functioned to enhance the production of antibacterial peptides from the insect and their antibacterial properties. This study indicates the potential of the peptides produced from larvae as antibacterial peptide substance for the development of novel antibacterial drugs.
21 citations
TL;DR: It is concluded that climate change could result in M. pruinosa invasion in a northward direction, suggesting the need for a thorough system of control and prevention.
Abstract: Globalization has changed the habitats of various species, resulting in harmful pest invasion. Among these pests, Metcalfa pruinosa has caused worldwide economic and hygienic damage in both urban and agricultural/forested areas. It has been reported that prediction of pest distribution is key to the management of pest prevention. Hence, this study aimed to predict the potential geographic distribution of M. pruinosa under the current climate and under a climate change scenario. CLIMEX, modeling software that analyzes the habitat suitability of a target species based on comprehensive climatic and physiological data, was used mainly to establish a map of predictive distribution of M. pruinosa at present and in the future. Based on our simulations, we predict that M. pruinosa will tend to extend its distribution northward in North America and Europe. We conclude that climate change could result in M. pruinosa invasion in a northward direction, suggesting the need for a thorough system of control and prevention.
19 citations
TL;DR: The Macrophya regia group is reviewed and five species are recognized from China, among them two new species, M. acutiserrula Li, Liu & Wei sp.
Abstract: The Macrophya regia group is reviewed and five species are recognized from China, among them two new species, M. acutiserrula Li, Liu & Wei sp. nov. and M. frontalis Li, Liu & Zhu sp. nov., and three known species, M. regia Forsius , M. maculoclypeatina Wei et al. 2003, and M. xiaoi Wei et al. 2003. A key to the Chinese species of the Macrophya regia group are provided.
19 citations
TL;DR: Analysis of the connection between food preferences as host specialization and the morphology of D. suzukii confirms that this extremely invasive species, found worldwide, is successful at spreading in part because of its potential to adapt rapidly under different rearing conditions.
Abstract: The invasive alien fruit pest Drosophila suzukii, (Matsumura 1931) causes economic loss in soft-skinned fruit production across Europe. After its first detection in 2008, the species has successfully expanded to a wide geographic area and invaded new host plants in a relatively short period of time. The aim of the present study was to analyze the connection between food preferences as host specialization and the morphology of D. suzukii. Population morphological variation in wings was investigated in two different host fruits (grape and strawberry) in which economic damage has been recorded. The geometric morphometric results revealed two noticeable wing shape morphotypes in D. suzukii (i.e. vein configuration) between the grape and strawberry fruits. Flies reared in grapes had wider wings, whereas flies grown in strawberries had more narrow wings. These differences in morphotype could be explained by the effects of wing aerodynamics, which affect the strength of the wings in flight. This, in turn, can lead to better dispersion within the associated fruit host. These results confirm that this extremely invasive species, found worldwide, is successful at spreading in part because of its potential to adapt rapidly under different rearing conditions. Therefore, adaptive variations in the wing shape of D. suzukii can be used to differentiate populations based on food preference (e.g. soft fruits) and can serve as an additional tool for detecting different bioecological types of D. suzukii.
16 citations
TL;DR: Results indicate that TmAttacin‐1a and ‐1b may be required for antimicrobial defenses in T. molitor.
Abstract: Antimicrobial peptides are effector molecules induced after microbial challenges. These form important components of innate host defense against the pathogens by exhibiting wide‐spectrum antimicrobial activities. In this study, we identified three attacin‐like genes from Tenebrio molitor RNASeq database using Tribolium castaneum attacin gene family as query. The T. molitor attacin gene family was annotated as TmAttacin‐1a [comprising of 154 amino acids (aa)], TmAttacin‐1b (150 aa) and TmAttacin‐2 (164 aa), respectively. Temporal expression analysis shows that the TmAttacin‐1a and ‐1b mRNAs are highly expressed in late larval stages, followed by a general decline in the pre‐pupal stages. The mRNA level shows a decline during metamorphosis, and gets slightly overexpressed in pupal‐adult transition stages. On the other hand, TmAttacin‐2 is mainly overexpressed at 1‐day old pupal stage. Spatial expression analysis indicates that TmAttacin‐1a, −1b, and −2 mRNAs are primarily expressed in gut and fat body, but not in hemocytes and Malpighian tubules in T. molitor larvae. Interestingly, TmAttacin‐1b shows more than 20‐fold expression in the ovary, whereas TmAttacin‐1a and −2 show similar expression patterns in gut, fat body, hemocyte, ovary, and testis in T. molitor adults. Induction pattern analysis demonstrates that the intracellular Gram‐positive bacteria, L. monocytogenes elicited the strongest response by inducing ~1,000‐fold expression of TmAttacin‐1a mRNA. The highest level of TmAttacin‐1b mRNA (~350‐fold) was induced by Gram‐negative bacteria, E. coli. However, the TmAttacin‐2 transcripts were not induced by microbial challenges. These results indicate that TmAttacin‐1a and ‐1b may be required for antimicrobial defenses in T. molitor.
16 citations
TL;DR: Commercial gel baits have improved and may be more effective than spray formulations against German cockroaches.
Abstract: The present study evaluated the efficacy of Maxforce gel baits containing 0.01% fipronil (Maxforce), 0.05% fipronil (Maxforce Magnum), 1.0% clothianidin (Maxforce Impact), and 0.6% indoxacarb (Avion gel bait; all from Bayer Environmental Science, Clayton, CA, USA) against reference and wild strains (Mobasher, Andisheh, Tamin‐e Ejtemaei, and Maskoni) of German cockroach collected in 2016. Test design and bait placement were according to World Health Organization (WHO) procedures for efficacy achieving a 95% mortality rate. Although cockroaches fed on all gel baits, gel baits containing clothianidin and indoxacarb were eaten at higher rates than gel baits containing 0.01% and 0.05% fipronil. The cumulative mortality rates reached 100% for all cockroach strains at 32, 28, 28 and 40 h after eating baits containing 0.01% fipronil, 0.05% fipronil, clothianidin, and indoxacarb, respectively. Efficacy (a 95% mortality rate) after exposure (consumption) of gel baits containing 0.05% fipronil and clothianidin was seen after 28 h, compared with 32 h for 0.01% fipronil and 40 h for indoxacarb. In conclusion, commercial gel baits have improved and may be more effective than spray formulations against German cockroaches.
TL;DR: Results indicate that 18S and MAT region mutations, as well as down‐regulated of CmMAT gene expression levels, may play important roles in C. militaris degeneration.
Abstract: The chemical composition and pharmacological effects of Cordyceps militaris are similar to those of Cordyceps sinensis, with the former undergoing greater development and utilization. Strain degeneration is a common phenomenon that occurs with high frequency during the subculturing of C. militaris, however, and the mechanism underlying strain degeneration remains unclear. In this study, we used touch-down PCR to compare the ITS1 + 5.8S + ITS2, 18S, 28S and mating-type (MAT) regions sequence of wild-type and degenerated strains of C. militaris. We also used quantitative real-time PCR to analyze expression levels of the CmMAT gene. Sequence analysis showed that the ITS1 + 5.8S + ITS2 and 28S regions of degenerated and wild-type strains were completely identical, the 18S region of the degenerated strain contained seven single-base mutations, including six base substitutions and one single-base insertion. Compared with the wild-type strain, the degenerated strain contained a deletion of the MAT1–2-1 region, three base substitutions in the MAT1–1-1 region, and a base substitution in the MAT1–1-2 region that causes a glycine-to-valine amino acid substitution. Quantitative real-time PCR analysis detected no CmMAT1–2-1 gene expression in the degenerated strain, confirming the deletion of the CmMAT1–2-1 gene. Expression levels of the CmMAT1–1-1 and CmMAT1–1-2 genes were significantly down-regulated to only 7.5 % and 4.4 %, respectively, that of the wild-type strain. These results indicate that 18S and MAT region mutations, as well as down-regulated of CmMAT gene expression levels, may play important roles in C. militaris degeneration. This study provides a theoretical basis for further elucidation of the molecular mechanisms of C. militaris degeneration.
TL;DR: Four major lepidopteran pests in major corn growing areas of Korea by employing sex pheromone traps from 2012 to 2015 were monitored to understand population dynamics and Helicoverpa armigera was found to be the main pest based on crop damage intensity.
Abstract: Lepidopterans such as Helicoverpa armigera are emerging pests of corn in Korea, causing huge yield losses and deteriorating the quality of the corn crop. We monitored four major lepidopteran pests in major corn growing areas of Korea by employing sex pheromone traps from 2012 to 2015 to understand population dynamics. H. armigera, Ostrinia furnacalis, Spodoptera litura, Spodoptera exigua and Mythimna separata were collected from April to October. Among these species, H. armigera was found to be the main pest based on crop damage intensity (80–90% of the total damage). H. armigera was generally observed during the earing stage of corn and would migrate to other fields during September to October for overwintering. We also tested select insecticides against larvae of H. armigera in the laboratory. The most effective insecticide was indoxacarb, which was applied at specific times to manage H. armigera in cornfields. Optimal timing of spraying was estimated at about 70 days after planting (earing season) to control for H. armigera. Additionally, two species of parasitoid (Therion circumflexum and Ophioninae sp.) were identified from H. armigera. However, more extensive surveys are needed to organize a control program based on natural enemies.
TL;DR: Chitin was extracted and physicochemically characterized from six Cicadas species collected from Mediterranean region of Turkey using a classic extraction method that includes acid and base treatment and the surface morphology of chitin isolates from Cicada species was observed to consist of nanofibers and nanopores.
Abstract: Due to the increasing interest in natural biopolymers including chitin, the exploitation of economic and easily accessible chitin sources with good physicochemical properties is nowadays required. In view of this fact, in the current study chitin was extracted and physicochemically characterized from six Cicadas (Hemiptera: Homoptera: Cicadoidea) species collected from Mediterranean region of Turkey (2014–15). Chitin was extracted using a classic extraction method that includes acid and base treatment. TGA results revealed a remarkable increase (410–412°C) for all the six Cicada species compared to other chitin samples extracted from various sources. For all of the six selected species the chitin contents on the dry basis were determined as 6.7% for Cicadatra atra, 5.51% for C. hyalina, 8.84% for C. platyptera, 4.97% for Cicada lodosi, 6.49% for C. mordoganensis, and 5.88% for Cicadetta tibialis. The surface morphology of chitin isolates from Cicada species was observed to consist of nanofibers and nanopores.
TL;DR: Results suggest that A. ludwigii extracts contain bioactive compounds, such as phenols and saponins, that may provide effective Cx.
Abstract: Chemical insecticides released into the environment may have adverse biological effects. Therefore, there is a need for ecofriendly insecticides for mosquito control. Xerophytic plant extracts that may provide more ecofriendly active component were evaluated against Culex pipiens 4th instars. Plant extracts prepared using different solvents with a Soxhlet apparatus and different concentrations were tested against Culex pipiens larvae. The effects were observed at 24 h and 72 h intervals and LD50 and LD90 values determined. Chloroform (CHCl3) and ethyl acetate (EtOAc) extracts of Althaea ludwigii were the most effective against Cx. pipiens 4th instars, but were highly dependent on extract concentrations and exposure time. Results suggest that A. ludwigii extracts contain bioactive compounds, such as phenols and saponins, that may provide effective Cx. pipiens larval control. However, the extract was found to be toxic to zebrafish larvae, and may be toxic to other aquatic fauna. Further studies to determine the active components and toxicity to other fauna are needed.
TL;DR: Results suggested that chalcones with JHAN activity could be useful for control of mosquito larvae, and 2′‐hydroxychalcone and cardamonin showed high levels ofJHAN and mosquito larvicidal activities.
Abstract: Widespread use of chemical insecticides has resulted in development of insect resistance and natural products with biological activities could become an attractive alternative to control insect pests. In order to find more effective insecticides for controlling mosquito, various mosquitocidal compounds are studied. Recently, juvenile hormone antagonists (JHANs) have been found to be to safe and effective insecticides for control of mosquito. In order to identify novel insecticidal compounds with JHAN activity, several chalcones were surveyed on their JHAN activities and larvicidal activities against Aedes albopictus larvae. Among them, 2′-hydroxychalcone and cardamonin showed high levels of JHAN and mosquito larvicidal activities. These results suggested that chalcones with JHAN activity could be useful for control of mosquito larvae.
TL;DR: Investigation of the survival rate of the flies at various concentrations of three chemicals and the lethal concentration values revealed that D. melanogaster exhibited higher tolerance than D. suzukii to all chemicals, supporting the hypothesis of different evolutionary adaptations to distinct habitats of the two flies.
Abstract: Drosophila melanogaster Meigen and Drosophila suzukii Matsumura are taxonomically close Drosophila species belonging to the family Drosophilidae and melanogaster group. D. melanogaster is thought to be evolutionarily adapted to overripe, decaying, and fermented fruits, in which large amounts of chemicals such as ethanol, acetic acid, and 2‐phenylethanol are produced, whereas, D. suzukii is attracted to fresh ripening fruit. Considering the distinct habitats of the two flies, D. suzukii is hypothesized to exhibit higher susceptibility to these chemicals than D. melanogaster. Therefore, in this study, we investigated the survival rate of the flies at various concentrations of three chemicals (2‐phenlyethanol, acetic acid, and ethanol) and calculated the lethal concentration (LC) values to compare the tolerance and susceptibility of D. melanogaster and D. suzukii to the chemicals. Our results revealed that D. melanogaster exhibited higher tolerance than D. suzukii to all chemicals, supporting the hypothesis of different evolutionary adaptations to distinct habitats of the two flies.
TL;DR: The results suggest that PTM pupae and egg would be the main overwintering stage in Korea where winter temperature does not drop below −15°C.
Abstract: Potato tuber moth (PTM), Phthorimaea operculella (Zeller), (Lepidoptera: Gelechiidae) is an invasive insect pest damaging solanaceous crops. We measured the supercooling point (SCP) and survival at low temperature of different development stages to determine which would be capable of overwintering in the Korean climate and adapting to low temperatures. The SCP ranges from −23.8°C of the egg to −16.8 of fourth instar larvae (L4). After short periods of low temperature acclimation in L3 (third instar larva), L4 and prepupae, only the prepupal stage showed a significant lowered SCP from −20.78 to −22.37°C. When exposed to different subzero temperature for two hours the egg turned out to be the most cold tolerant stage showing LT₅₀ of −21.7°C followed by the pupal stage with −15.89°C. One hundred percent mortality was observed when the larvae or adults were exposed to temperatures below −15.1°C even for a period as short as 2 h. The results suggest that PTM pupae and egg would be the main overwintering stage in Korea where winter temperature does not drop below −15°C.
TL;DR: Four different types of sensilla are present on the labial and maxillary palps of both sexes of C. chinensis and there are no differences on the morphology of maxillary palp and labial palp between female and male.
Abstract: Callosobruchus chinensis (Coleoptera: Bruchidae) is the main pest of mungbean (Vigna radiata) especially during seed storage. To provide background information for chemical ecology studies, we examined the externalmorphology of the antennal, maxillary palp and labial palp sensilla of this insect with scanning electron microscopy. The antennae of adult C. chinensis exhibited sexual dimorphism. The female have serrated antenna and the male have pectinate morphology. Eight sensillum types have been observed on the antennae of both sexes: Böhm bristles, sensilla chaetica, sensilla trichodea, sensilla basiconica, sensilla styloconicum, sensilla coeloconica, sensillum campaniformia, sensilla cavity. There are no differences on the morphology of maxillary palp and labial palp between female and male. Four different types of sensilla are present on the labial and maxillary palps of both sexes of C. chinensis: sensilla chaetica, sensilla twig basiconica, sensilla basiconica, sensilla digitiformia.
TL;DR: Insight is provided into the response of C. cunea to abiotic stresses and insight into the use of this parasitoid in biological control strategies is provided.
Abstract: Heat shock proteins (HSPs) are known to be induced in response to various stress factors. Although HSPs have been studied in a number of insects, not much is known about HSPs in the natural enemies of insects, especially parasitoids. In this study, we identified and characterized five full‐length HSP genes (Cchsp40, Cchsp60, Cchsp70, Cchsp83, and Cchsp90) from an endoparasitic chalcid wasp, Chouioia cunea, which parasitizes the fall webworm, Hyphantria cunea pupae, a worldwide pest. The expression of Cchsps in response to temperature, pesticide stresses and UV radiation were also investigated by quantitative real‐time polymerase chain reaction (RT‐qPCR). The results showed that all five Cchsps were induced in response to hot and cold temperatures. Four pesticides induced the abundant expression of Cchsp70, Cchsp83 and Cchsp90 while ultraviolet radiation up‐regulated Cchsp40, Cchsp70, Cchsp83 and Cchsp90. These results indicate the different transcriptional profiles of the five different Cchsps in response to various abiotic stresses. The findings of this study provide insights into the response of C. cunea to abiotic stresses and insight into the use of this parasitoid in biological control strategies.
TL;DR: Results showed that concurrent treatments with 1‐MCP and EF could be suitable for commercial purposes by extending shelf life, delaying color changes and softening, and offering complete control of the target pest, Tetranychus urticae.
Abstract: Extending the shelf life of fruits during post‐harvest storage and eradicating pests associated with quarantine issues could together comprise the key steps toward expanding the exportation of sweet persimmon in South Korea. Here we firstly investigated the concurrent application of ethyl formate (EF), a methyl bromide alternative fumigant, which is currently considered a beneficial and safe fumigant in quarantine use, and 1‐methylcyclopropene (1‐MCP), an anti‐ethylene compound that is broadly used in post‐harvest systems, on sweet persimmon. We also suggest the proper fumigation methods to be follow when using these compounds. Tetranychus urticae, an important quarantine pest, was inoculated under the calyx of sweet persimmon, and the fruits were then fumigated using 35.0 mg L−1 of EF for 6 h before and after treating with 1.0 μL L−1 of 1‐methylcyclopropene for 24 h under storage conditions of 5°C. Our results showed that concurrent treatments with 1‐MCP and EF could be suitable for commercial purposes by extending shelf life, delaying color changes and softening, and offering complete control of the target pest, Tetranychus urticae.
TL;DR: Adult mosquito surveillance was conducted at four cattle sheds, a wild bird refuge, and two residential areas located in Gyeongnam Province in the Republic of Korea to figure out population densities of vector mosquitoes, possibly invaded mosquitoes and identify various virus infections at the selected sites.
Abstract: Adult mosquito surveillance was conducted from 2013 through 2014 at four cattle sheds, a wild bird refuge, and two residential areas located in Gyeongnam Province in the Republic of Korea. Adult mosquitoes were collected in black light traps from April 1, through November 30. Mosquito surveillance was conducted to figure out population densities of vector mosquitoes, possibly invaded mosquitoes and identify various virus infections at the selected sites. A total of 107,466 females comprising 14 species and 7 genera were collected from 2013 to 2014. The most common species collected were Culex tritaeniorhynchus Giles (63.8%), Anopheles sinensis s.l. (18.9%), Aedes vexans nipponii (Theobald) (7.7%), and Culex pipiens Coquillett (5.1%). Trap indices (TIs) varied widely for species over their range, due to geographical distribution and degree of association with rural and urban communities. The most collected An. sinensis s.l. and Cx. tritaeniorhynchus appeared at a cow shed in Hapcheon (TI 347.5) and a pigsty in Daejeo‐1‐dong, Busan (TI 1,040.8), respectively, due in part to their situation near breeding sites such as rice paddies. The bi‐weekly population densities for mosquito species were variable for each of the years, apparently as a result of variable annual weather conditions. None of the mosquito species collected tested for the flavivirus including Japanese Encephalitis Virus, West Nile Virus, Dengue Virus, and Zika Virus infections by polymerase chain reaction (PCR) assay were positive.
TL;DR: Seven different strains of Beauveria bassiana were used in a bioassay on Pieris rapae larvae and the results showed that an B. bassiana strain showed relatively high pathogenicity towards P.Rapae larvae.
Abstract: Seven different strains of Beauveria bassiana were used in a bioassay on Pieris rapae larvae. The results showed that an B. bassiana strain showed relatively high pathogenicity towards P. rapae larvae. The adjusted mortality rate was 92.86 %, and the infection rate was 85.71 % in 10 days post inoculation. Molecular identification was performed to identify the unknown strain. Internal Transcribed Spacer sequence analysis showed that the polymerase chain reaction amplicon length of the unknown strain of Beauveria sp. was 573 bp, and sequence similarity to the known B. bassiana sequences in the NCBI database was 99 %. The B. bassiana strain was named Bb01. The changes of proteins and PPO of P. rapae larvae infected by B. bassiana Bb01 strain at different times was determined. The activity of PPO increased in 1–6 d and decreased in 7 d again after inoculation. The B. bassiana invaded into the insect body affected the balance of the proteins and PPO.
TL;DR: The genome sequence, annotation, and analysis of A. m.
Abstract: Apis mellifera intermissa is the native honey bee subspecies of Algeria, and approximates a position among bee races between tropical African and European breeds. This bee is very aggressive, nervous, and produces many broods with many queen cells. It is prone to swarming and exhibits defensive behavior and an abundant use of propolis. In the present study, pure line samples of A. m. intermissa collected from Blida (Algeria; 36°31′N, 2°58′E) with preferable Varroa resistance confirmed their through hygienic cleaning behavior and high temperature adaptation, were selected as a reference sample for full‐genome sequencing. Array comparative genomic hybridization (aCGH) was also performed on the same samples to validate genomic variations. These analyses will be an important source of information for the honey bee research community worldwide. The 240‐Mb genome was annotated with 26 355 transcripts and analyzed. Analysis of 133 pathways indicated an abundance of pathways related to metabolic processes, the biosynthesis of secondary metabolites, and biodegradation of xenobiotics . In addition to simple sequence repeat markers, variant analysis for beneficial trait genes, transposons, and phylogeny was performed. The mitochondrial genome and genes involved in immunity and chemoreception were identified and compared with those from other sequenced insect models. The indels obtained by sequencing were validated by aCGH. The genome sequence, annotation, and analysis of A. m. intermissa provides new understanding of the function of bee genes, and comparison with the genome of other A. mellifera subspecies promises to yield insights into the evolution of the adaptations to high temperature and resistance to Varroa parasite infestation.
TL;DR: Comparisons of the wing morphology, female and male genitalia, 3′‐end region of the cytochrome c oxidase I (COI) gene sequence, and internal transcribed spacer (ITS) 2 sequence of the Korean specimens with those of the D. superans specimens from Japan consistently supported the presence of D. sibiricus in South Korea, suggesting a low genetic divergence between the two species.
Abstract: In the present study, specimens of Dendrolimus superans collected from South Korea suggest the presence of D. sibiricus, instead of D. superans. Comparisons of the wing morphology, female and male genitalia, 3′‐end region of the cytochrome c oxidase I (COI) gene sequence, and internal transcribed spacer (ITS) 2 sequence of the Korean specimens with those of the D. superans specimens from Japan consistently supported the presence of D. sibiricus in South Korea. Phylogenetic analyses of the concatenated sequences of COI and ITS2 from the available sequence types of D. sibiricus and D. superans, along with South Korean specimens, were conducted using the Bayesian inference (BI) and maximum likelihood (ML) methods. These phylogenetic analyses placed the South Korean specimens with the Russian D. sibiricus as an inclusive group, excluding the Japanese D. superans, indicating the distribution of D. sibiricus in South Korea. Nevertheless, D. superans formed a distinct group only by BI analysis (Bayesian posterior probabilities = 0.89), whereas D. sibiricus, including the South Korean samples, formed a distinct group only by the ML analysis (99%), suggesting a low genetic divergence between the two species.
TL;DR: The TEM results showed severe damage to the larval cuticle after hyphae infection, which meant that the structure of the cuticle became thinner and eventually flocculent; muscle tissues were dissociated and eventually stuck to the Hyphae, and the corpus adiposum was loose and deformed, and eventually degraded.
Abstract: In the present study we investigated the infection process of Beauveria bassiana on Xylotrechus rusticus larvae using scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The SEM results showed that B. bassiana spores germinated on the surface of the larval body and invaded the larva as an appressorium. The hyphae then germinated from the spores and spread throughout the larval body. After the death of the larva, conidiophores formed at one end of the hypha on the surface of the larval body and prepared for a new round of infection. The TEM results showed severe damage to the larval cuticle after hyphae infection. The structure of the cuticle became thinner and eventually flocculent; muscle tissues were dissociated and eventually stuck to the hyphae, and the corpus adiposum was loose and deformed, and eventually degraded.
TL;DR: The alimentary canal morphology of S. insularis was observed using light microscopy, and its ultrastructure was investigated by scanning and transmission electron microscopy to provide the basis for further studies of the structure and function in S.insularis larvae.
Abstract: Streltzoviella insularis (Staudinger) is an important tree‐boring pest, that primarily damages Sophora japonica (Linnaeus) and Ginkgo biloba (Linnaeus), as well as other common species, at great economic cost to the urban landscape construction industry in China. In the present study, the alimentary canal morphology of S. insularis was observed using light microscopy, and its ultrastructure was investigated by scanning and transmission electron microscopy. The foregut of S. insularis can be divided into the pharynx, esophagus, crop, proventriculus, and cardiac valve. The well‐developed crop forms the longest section of the foregut. It is able to store large amounts of food and is lined with a monolayer of epithelial cells. Many sclerotized microspines occur on the surface of the anterior intima and there are dense spines on the posterior intima of the proventriculus. Epithelial cells of the midgut include columnar cells, goblet cells, and regenerative cells, but endocrine cells are absent. The hindgut consists of the pyloric valve, ileum, and rectum. There is no clear distinction between the ileum and colon. The intima surface of the pyloric valve carries many microspines, whereas the intestinal wall of the rectum is thin with well‐developed rectal pads. The rectal epithelial cells form a squamous monolayer. A cryptonephric excretory system is located in the hindgut. There are six spiral Malpighian tubules, in which a cellular layer on a basement membrane encloses a lumen. These results will provide the basis for further studies of the structure and function in S. insularis larvae.
TL;DR: The Korean shoot fly genus Atherigona Rondani is reviewed taxonomically and bifurca sp.
Abstract: The Korean shoot fly genus Atherigona Rondani is reviewed taxonomically. A total of five species was identified: A. (Acritochaeta) orientalis Schiner, A. (Atherigona) biseta Karl, A. (Atherigona) falcata (Thomson), A. (Atherigona) oryzae Malloch, and A. (Atherigona) bifurca sp. nov. Of these, A. (Atherigona) bifurca sp. nov. is new to science, and A. (Atherigona) biseta Karl and A. (Atherigona) falcata (Thomson) are reported for the first time in Korea. A key to Korean species and photographs of external features are provided.
TL;DR: Morphological characteristics for accurate identification of the species, a list of hosts, and damage patterns are described to provide plant quarantine information for pest management.
Abstract: Occurrence of the invasive quarantine pest fly, Atherigona (Atherigona) oryzae Malloch, is hereby recorded for the first time in Gyeongsangbuk‐do Province, Korea. Morphological characteristics for accurate identification of the species, a list of hosts, and damage patterns are described to provide plant quarantine information for pest management.
TL;DR: It is found that Nfs1 gene has a lower expression level upon silencing than SDH gene, the gene that is easier to silence, and intrathoracic injection of 500 ng of dsRNAs per mosquito is recommended to achieve effective knockdown for well‐silenced transcripts such as NFS1 for up to 3 weeks.
Abstract: RNA interference is widely used to analyze gene functions via phenotypic knockdown of target transcripts in mosquitoes, which transmit numerous mosquito-borne diseases. Functional analysis of mosquito genes is indispensable to understand and reduce transmission of mosquito-borne diseases in mosquitoes. Intrathoracic injection of double-stranded RNA (dsRNA) remains the simplest and most customizable method in mosquitoes for functional analysis of the genes of interest. However, achieving consistent and effective knockdown by dsRNAi is often elusive and may require extensive optimization. We tested the effectiveness of gene silencing by intrathoracic injection of four different quantities of dsRNA targeting two Ae. aegypti genes, cysteine desulfurylase (Nfs1) and short-chain dehydrogenase (SDH). We found that Nfs1 gene has a lower expression level upon silencing than SDH gene. In the case of the gene that is easier to silence, Nfs1 gene expression was significantly silenced by all four tested quantities of dsRNA up to 21 d.p.i., but silencing of SDH, the gene that is difficult to silence, was less effective, with knockdown lasting up to 9 d.p.i. only when 1,000 ng of dsRNA was used. Based on our observation, intrathoracic injection of 500 ng of dsRNAs per mosquito is recommended to achieve effective knockdown for well-silenced transcripts such as Nfs1 for up to 3 weeks. This includes most in vivo bioassays involving arboviral infections in Ae. aegypti. The estimated quantities of dsRNA described in this study should be applicable to most Ae. aegypti dsRNAi studies and thus provide a guideline to develop efficient dsRNAi in other experimental investigations.