Search Results (29)

The parasitoid wasp Anisopteromalus calandrae (Howard) (Hymenoptera: Pteromalidae) has the potential for biological control against insect pests in stored grains, mainly of the orders Coleoptera and Lepidoptera. microRNAs (miRNAs) are small non-coding RNA fragments of importance in the regulation of gene translation in most physiological processes, and the study of miRNAs in wasps can be useful for understanding the physiology of these insects. The objective of this study was to evaluate for the first time the miRNomic profile of A. calandrae and to determine its conservation in five species of the order Hymenoptera (Apis mellifera, Dinoponera quadriceps, Nasonia giraulti, N. longicornis and N. vitripennis). Using molecular techniques and bioinformatics tools, a total of 108 miRNAs were identified (75 conserved between species and 34 de novo). These miRNAs were found to be related to embryogenesis, signaling, metabolic, biological and immune functions. The miRNomic signature of A. calandrae is important for the study of the physiology of wasps and the order Hymenoptera. Full article

Eulophidae and Pteromalidae are parasitic wasps with a global distribution and import for the biological control of pests. They can be distributed in different altitude regions, but their morphological and genetic adaptations to different altitudes are unclear. Here, we collected specimens that belong to Eulophidae and Pteromalidae from various altitudinal gradients, based on integrated taxonomic approaches to determine the species composition, and we analyzed their body shape and size from different altitudes using geometric morphometrics. Then, we performed an analysis of the D. isaea population’s haplotype genes to illustrate their genetic diversity. As a result, eight species that belong to two genera, Diglyphus Walker (Eulophidae) and Pachyneuron Walker (Pteromalidae), were identified, including two newly recorded species from China (D. chabrias and D. sabulosus). Through a geometric morphometrics analysis of body shape, we found that a narrow forewing shape and a widened thorax are the significant characteristics of adaptation to high-altitude environments in D. isaea and P. aphidis. Additionally, the body size studies showed a principal relationship between centroid size and altitude; the size of the forewings and thorax increases at higher altitudes. Next, using haplotype analysis, 32 haplotypes were found in seven geographic populations with high genetic diversity of this species. Our research provides preliminary evidence for the morphological and genetic diversity adaptation of parasitic wasps to extreme environments, and these data can provide important references for investigations on the ecological adaptability of parasitic wasps. Full article

Soybeans are a valuable crop in many countries of the world. To obtain stable yields, it is necessary to consider the activities of arthropods, both beneficial and destructive. The results of this study indicate high biodiversity. Most of the insects that feed on soy are polyphagous. In the years favorable for their development, omnivorous pests pose a serious threat to soybeans. The species composition of arthropods on soybeans of the Krasnodar and Stavropol territories of the Russian Federation during the years of the study was represented by 212 species (210 species of insects and 2 species of mites), including 101 species of phytophagous insects, which accounted for 48.5% of the total fauna and 109 species of entomophagous insects (51.7%). Most of the entomophages were parasitic Hymenoptera belonging to such families as Ichneumonidae, Braconidae, Aphidiidae, Eurytomidae, Ormyridae, Pteromalidae, Encyrtidae, Eupelmidae, Eulophidae, Elasmidae, Scelionidae, Platygastridae, and Chrysididae. The most numerous phytophagous insects damaging soybeans belonged to the Hemiptera order (34 out of 101 species of phytophages). The Lepidoptera order in the soybean agrocenosis was represented by 28 species (13.4% of the total fauna and 28.0% of the destructive fauna). Full article

The ber fruit fly (BFF), Carpomya vesuviana Costa, 1854 (Diptera: Tephritidae), is an important key pest of the jujube, Ziziphus jujuba Miller. The main control measures against this pest are to use chemical control, but the first survey for its natural enemies was performed in Iran. Here, we report eight species of parasitic wasps of the BFF from five different families. The family Eurytomidae with three species, the families Pteromalidae and Mutillidae with two species each, and the families Braconidae and Diapriidae with one species each are associated with different immature stages of the BFF, of which Eurytoma pineticola Zerova (Eurytomidae) and Cyrtoptyx lichtensteini (Masi) (Pteromalidae) were the most abundant parasitoid species. Fopius carpomyiae (Silvestri,) was not reared on BFF on the jujube during this survey, but it was reported on Ziziphus spina-christi (L.) with a high parasitism rate. Therefore, it seems to be the most important parasitoid of BFF in Iran. The parasitoid community of BFF in Khorasan, Eastern Iran, is reviewed, and an identification key to these species is proposed. Full article

Insects employ multifaceted strategies to combat invading fungi, with immunity being a promising mechanism. Immune pathways function in signal transduction and amplification, ultimately leading to the activation of antimicrobial peptides (AMPs). Although several studies have shown that immune pathways are responsible for defending against fungi, the roles of parasitoid immune pathways involved in antifungal responses remain unknown. In this study, we evaluated the roles of the Toll and IMD pathways of a pupal parasitoid, Pteromalus puparum (Hymenoptera: Pteromalidae), in fighting against Beauveria bassiana (Hypocreales: Cordycipitaceae). Successful colonization of B. bassiana on P. puparum adults was confirmed by scanning electron microscopy (SEM). AMPs were induced upon B. bassiana infection. The knockdown of key genes, PpTollA and PpIMD, in Toll and IMD signaling pathways, respectively, significantly compromised insect defense against fungal infection. The knockdown of either PpTollA or PpIMD in P. puparum dramatically promoted the proliferation of B. bassiana, resulting in a decreased survival rate and downregulated expression levels of AMPs against B. bassiana compared to controls. These data indicated that PpTollA and PpIMD participate in Toll and IMD-mediated activation of antifungal responses, respectively. In summary, this study has greatly broadened our knowledge of the parasitoid antifungal immunity against fungi. Full article

The composition and seasonal abundance of hymenopteran parasitoids of Liriomyza trifolii (Burgess) was investigated on snap bean (Phaseolus vulgaris L.), tomato (Solanum lycopersicum L.), and squash (Cucurbita pepo L. ‘Enterprise’) from 2010 to 2016 in South Florida in two studies. In the first study (2010–2016), 13 species of parasitoids were collected from the snap bean crop. Opius dissitus Muesebeck (Braconidae) was the most abundant parasitoid throughout the study period from September 2010 to February 2016. Diaulinopsis callichroma Crawford (Eulophidae) was the second most abundant parasitoid on bean in 2010, 2012, 2014, and 2016. Other parasitoids included Euopius sp. (Braconidae)., Diglyphus begini (Ashmead), D. intermedius (Girault), D. isaea (Walker), Neochrysocharis sp., Closterocerus sp., Chrysocharis sp., Zagrammosoma lineaticeps (Girault), Z. muitilineatum (Ashmead), Pnigalio sp. (all Eulophidae), and Halticoptera sp. (Pteromalidae). In the second study on the comparative abundance of parasitoids in three crops conducted in 2014 and 2016 using bean (Phaseolus vulgaris L., tomato (Solanum lycopersicum L.) and squash (Cucurbita pepo L.) arranged in a randomized complete block design, bean attracted more parasitoids than tomato and squash irrespective of parasitoid species and years. This information will help in devising a biocontrol-based integrated program for managing leafminers in beans and other vegetable crops. Full article

The genus Ceutorhynchus Germar (Coleoptera: Curculionidae) is composed of canola pests, natural enemies of Brassicaceae, and other species associated with non-crop and non-weed plants. This study aimed to establish trophic associations of Ceutorhynchus with their host plants and with their parasitoids in the agricultural landscape, in order to assess the actual beneficial or noxious ecological roles of the insects. Trophic associations were established by identifying Ceutorhynchus species and their parasitoids emerging from collected Brassicaceae plants in areas adjacent to canola fields and other crops in 2019 and 2020. Five Ceutorhynchus species were collected and identified as hosts of parasitoids in the families Pteromalidae and Eulophidae. Two functional groups were characterized: natural enemies of weeds and agricultural pests. The exotic wormseed wallflower, Erysimum cheiranthoides was identified as a new host plant of the invasive canola pest Ceutorhynchus obstrictus (Marsham), and the native tower rockcress, Arabis glabra, as a new host plant of the native Ceutorhynchus neglectus Blatchley. Association between the exotic Ceutorhynchus typhae (Herbst) and a parasitoid of the genus Elachertodomyia is reported for the first time. Finally, Ceutorhynchus neglectus and C. typhae hosted the exotic parasitoid Trichomalus perfectus, an important natural enemy of C. obstrictus. Full article

The mitochondrial genomes of Muscidifurax similadanacus, M. sinesensilla, Nasonia vitripennis, and Pachycrepoideus vindemmiae were sequenced to better understand the structural evolution of Pteromalidae mitogenomes. These newly sequenced mitogenomes all contained 37 genes. Nucleotide composition was AT-biased and the majority of the protein-coding genes exhibited a negative AT skew. All 13 protein-coding genes (PCGs) initiated with the standard start codon of ATN, excepted for nad1 of N. vitripennis, which started with TTG, and terminated with a typical stop codon TAA/TAG or an incomplete stop codon T. All transfer RNA (tRNA) genes were predicted to fold into the typical clover-leaf secondary structures, except for trnS1, which lacks the DHU arm in all species. In P. vindemmiae, trnR and trnQ lack the DHU arm and TΨC arm, respectively. Although most genes evolved under a strong purifying selection, the Ka/Ks value of the atp8 gene of P. vindemmiae was greater than 1, indicating putative positive selection. A novel transposition of trnR in P. vindemmiae was revealed, which was the first of this kind to be reported in Pteromalidae. Two kinds of datasets (PCG12 and AA) and two inference methods (maximum likelihood and Bayesian inference) were used to reconstruct a phylogenetic hypothesis for the newly sequenced mitogenomes of Pteromalidae and those deposited in GenBank. The topologies obtained recovered the monophyly of the three subfamilies included. Pachyneurinae and Pteromalinae were recovered as sister families, and both appeared sister to Sycophaginae. The pairwise breakpoint distances of mitogenome rearrangements were estimated to infer phylogeny among pteromalid species. The topology obtained was not totally congruent with those reconstructed using the ML and BI methods. Full article

Non-pollinating fig wasps (NPFWs), particularly long-ovipositored Sycoryctina wasps, exhibit a high species specificity and exert complex ecological effects on the obligate mutualism between the plant genus Ficus and pollinating fig wasps. Apocrypta is a genus of NPFWs that mostly interacts with the Ficus species under the subgenus Sycomorus, and the symbiosis case between Apocrypta and F. pedunculosa var. mearnsii, a Ficus species under subgenus Ficus, is unique. As fig’s internal environments and the wasp communities are distinct between the two subgenera, we addressed the following two questions: (1) Are the parasitism features of the Apocrypta wasp associated with F. pedunculosa var. mearnsii different from those of other congeneric species? (2) Is this Apocrypta species an efficient wasp that lives in its unique host? Our observation revealed that this wasp is an endoparasitic idiobiont parasitoid, as most congeneric species are, but developed a relatively long ovipositor. Furthermore, the relationships of the parasitism rate versus the pollinator number, the fig wall, and the sex ratio of the pollinator, respectively, showed that it possessed a higher parasitism ability than that of other congeners. However, its parasitism rate was low, and thus it was not an efficient wasp in its habitat. This difference between parasitism ability and parasitism rate might be a consequence of its oviposition strategy and the severe habitat conditions. These findings may also provide insights into the mechanism to maintain the interaction between the fig tree and the fig wasp community. Full article

The cabbage seedpod weevil (CSW), Ceutorhynchus obstrictus, an exotic pest accidentally introduced in North America in 1931, spread all over this continent and is now a major pest of canola crops. One of its main natural enemies in Europe, Trichomalus perfectus, was observed in eastern Canada in 2009. This study aimed to evaluate the landscape influence on CSW infestation and abundance and on T. perfectus parasitism in Quebec to understand the optimal conditions to potentially release this parasitoid in the Canadian Prairies. Field research was conducted in 19 to 28 canola fields per year, from 2015 to 2020, among eight Quebec regions. CSW was sampled by sweep net during canola blooming and parasitoids by collecting canola pods kept in emergence boxes until adults emerge. Infestation and parasitism calculations were based on pod emergence holes. For analysis, 20 landscape predictors were considered. Results show that CSW infestation and abundance increased if there were more roads and cereal crops in the landscapes. Meanwhile, T. perfectus parasitism decreased when hedgerows length and distance from water were longer. However, it increased when landscape diversity and average crop perimeter-to-area ratio were higher, and along with more hay/pastures and soybean crops. This study’s results highlight that these four landscape predictors could provide more resources and overwintering areas, promoting greater efficiency of T. perfectus to control the CSW. Full article

Scutellista ciruela Fonscolombe has a significant controlling effect on the rubber tree pest, Parasaissetia nigra Nietner. To identify the optimal conditions for the population growth of S. caerulea, we assessed how temperature, photoperiod, and supplementary nutrition affected its development and reproduction. The results demonstrated that the number of eggs laid and parasitism rates of S. caerulea were the highest at 33 °C. The developmental rate of S. caerulea was the fastest and the number of emerged adults the highest. The number of eggs laid and the parasitism rates increased when the light duration increased within a day. Females did not lay any eggs when the whole day was dark. At a photoperiod of 14:10 (L:D), the developmental duration was the shortest and the number of emerged adults was the highest. Adult life span was the longest under a 12:12 (L:D) photoperiod. During the adult stage, supplementary nutrition, such as sucrose, fructose, honey, and glucose, increased the life span of S. caerulea. The life span of S. caerulea was longer when provided with a supplementary diet of sucrose or honey, compared to other tested diets. The results suggested that the most suitable conditions for S. caerulea’s population growth were the following: 30 to 33 °C, with 12 to 14 h of daylight, and the provision of sucrose or honey as supplemental diet for the adults. Full article

Body size is the most essential feature that significantly correlates with insects’ longevity, fecundity, metabolic rate, and sex ratio. Numerous biogeographical rules have been proposed to illustrate the correlation between the body sizes of different taxa and corresponding geographical or environmental factors. Whether the minute and multifarious chalcids exhibit a similar geographical pattern is still little known. In this research, we analyzed morphological data from 2953 specimens worldwide, including the two most abundant and diverse taxa (Pteromalidae and Eulophidae), which are both composed of field-collected and BOLD system specimens. We examined forewing length as a surrogate of body size and analyzed the average size separately for males and females using two methods (species and assemblage-based method). To verify Bergmann’s rule, we included temperature, precipitation, wind speed and solar radiation as explanatory variables in a generalized linear model to analyze the causes of the size variation. We found that there was an increasing trend in the body size of Pteromalidae and Eulophidae with altitude. The optimal Akaike information criterion (AIC) models showed that larger sizes are significantly negatively correlated with temperature and positively correlated with precipitation, and the possible reasons for this variation are discussed and analyzed. Full article

Cereals are very common and widespread crops in Europe. Aphids are a diverse group of herbivorous pests on cereals and one of the most important limiting factors of cereal production. Here, we present an overview of knowledge about the taxonomy, biodiversity, and ecology of cereal aphid parasitoids in Europe, an important group of natural enemies contributing to cereal aphid control. We review the knowledge obtained from the integrative taxonomy of 26 cereal aphid primary parasitoid species, including two allochthonous species (Lysiphlebus testaceipes and Trioxys sunnysidensis) and two recently described species (Lipolexis labialis and Paralipsis brachycaudi). We further review 28 hyperparasitoid species belonging to three hymenopteran superfamilies and four families (Ceraphronoidea: Megaspillidae; Chalcidoidea: Pteromalidae, Encyrtidae; Cynipoidea: Figitidae). We also compile knowledge on the presence of secondary endosymbionts in cereal aphids, as these are expected to influence the community composition and biocontrol efficiency of cereal aphid parasitoids. To study aphid–parasitoid–hyperparasitoid food webs more effectively, we present two kinds of DNA-based approach: (i) diagnostic PCR (mainly multiplex PCR), and (ii) DNA sequence-based methods. Finally, we also review the effects of landscape complexity on the different trophic levels in the food webs of cereal aphids and their associated parasitoids, as well as the impacts of agricultural practices and environmental variation. Full article

The melon fly, Bactrocera cucurbitae Coquillett (Diptera: Tephritidae), is a quarantine pest that causes considerable economic losses to growers of vegetables and fruits worldwide. Spalangia endius (Walker) (Hymenoptera: Pteromalidae) is a solitary pupal parasitoid of various dipteran hosts. We assessed the impact of the host pupal age (2, 4, and 6 days old), host density (5, 10, 15, 20, 25, and 30), and parasitoid density (1, 2, 3, 4, 5, and 6) on the parasitizing potential of S. endius on B. cucurbitae pupae under laboratory conditions. The effects of different soil depths on the parasitism rate of S. endius and the dispersal behavior of S. endius at distances of 0, 5, and 10 m were also evaluated under field conditions. The results showed that the parasitism rate of S. endius significantly increased with the increase in host density and parasitoid density. The host pupal age did not influence the number of pupae parasitized by S. endius and the progeny sex ratio of S. endius under different host densities. In the fields, different puparium burial depths of B. dorsalis pupae significantly influenced the parasitism and eclosion rates of S. endius but did not influence the eclosion rate of B. cucurbitae. Spalangia endius females could travel up to 10 m to parasitize at a similar rate on B. cucurbitae pupae compared to S. endius placed at 0 m. Full article

In developing countries, intercropping is commonly used to boost land productivity and agricultural benefits. However, in the Yucatan region of Mexico, maize (Zea mays L.) yields remain low, despite consistent fertilizer and pesticide inputs in traditional intercropping systems. Furthermore, little is known about the photosynthetic mechanisms that occur when maize plants interact with legumes, and there is a lack of understanding of how intercropping systems affect other organisms in the system, such as beneficial and insect pest population dynamics. A field experiment was carried out on the Yucatan Peninsula in 2021 to assess the impact of maize–legume intercropping systems on maize yield, physiological characteristics as evaluated by gas exchange measurements, and the abundance of beneficial insects in traditional and novel maize intercropping systems. The experiment was carried out with a randomized complete block design with three replicates. Treatments included maize intercropped with a novel legume, crotalaria (Crotalaria juncea L.), maize intercropped with a traditional legume, cowpea (Vigna unguiculata (L.) Walp.), and sole maize as a control. Significant differences in plant height were shown at growth stages V12 (45 days after sowing) and VT (60 days after sowing). No differences were observed in stem diameter, leaf area index, or chlorophyll content. The maize/cowpea intercrop increased the photosynthesis rate by 12.9% and 9.84% in the maize/crotalaria and sole maize, respectively (p < 0.001), and transpiration rate by 6.5% and 8.5% in the maize intercropped with crotalaria and sole maize treatments, respectively (p < 0.001), of maize plants. No significant effects on stomatal conductance or water use efficiency were observed, but the carbon intercellular rate was reduced by 9.74% and 9.15 when compared to the maize/crotalaria and the sole maize treatments, respectively. Overall, intercropping treatments attracted more beneficial insects than sole maize. For predators, the families that stood out were Coccinelidae, Formicidae, Araneidae, Thomisidae, Syrphidae, Chrysomelidae, Oxypidae, Vespidae, Reduviidae, Carabidae, Asilidae, Salthicidae, Dolichopodidae, while among parasitoids, the most frequent families were Eurytomydae, Braconidae, Tachinidae, Pteromalidae, Scelionidae, and Figitidae. In comparison to the maize/cowpea and maize/crotalaria treatments, the sole maize treatment resulted in a grain yield increase of 24.5% and 32%, respectively. However, sole maize was not statistically different to that of maize/cowpea intercropping. In conclusion, our findings suggest that maize/cowpea intercropping could be a viable alternative to sole maize cropping systems for enhancing maize yield and the abundance of beneficial insects, without increasing interspecific competition with the maize crop. Therefore, the maize/cowpea intercropping system represents a sustainable planting alternative for promoting maize grain yield and also promoting edible legume production within the system. Furthermore, the outcomes of this study can serve as a theoretical framework for increasing maize–legume intercropping profitability under growing conditions on the Yucatan Peninsula. Full article