microRNAs in Syrista parreyssi (Hymenoptera) and Lepisma saccharina (Zygentoma) possibly involved in the mitochondrial function.

Mitochondria are essential organelles for maintaining vital cellular functions, and microRNAs (miRNAs) regulate gene expression posttranscriptionally. miRNAs exhibit tissue and time-specific patterns in mitochondria and specifically mitochondrial miRNAs (mitomiRs) can regulate the mRNA expression both originating from mitochondrial and nuclear transcription which affect mitochondrial metabolic activity and cell homeostasis. In this study, miRNAs of two insect species, Syrista parreyssi (Hymenoptera) and Lepisma saccharina (Zygentoma), were investigated for the first time. The known and possible novel miRNAs were predicted and characterized and their potential effects on mitochondrial transcription were investigated in these insect species using deep sequencing. The previously reported mitomiRs were also investigated and housekeeping miRNAs were characterized. miRNAs that are involved in mitochondrial processes such as apoptosis and signaling and that affect genes encoding the subunits of OXPHOS complexes have been identified in each species. Here, 81 and 161 novel mature miRNA candidates were bioinformatically predicted and 9 and 24 of those were aligned with reference mitogenomes of S. parreyssi and L. saccharina, respectively. As a result of RNAHybrid analysis, 51 and 69 potential targets of miRNAs were found in the mitogenome of S. parreyssi and L. saccharina, respectively. cox1 gene was the most targeted gene and cytB, rrnS, and rrnL genes were highly targeted in both of the species by novel miRNAs, hypothetically. We speculate that these novel miRNAs, originating from or targeting mitochondria, influence on rRNA genes or positively selected mitochondrial protein-coding genes. These findings may provide a new perspective in evaluating miRNAs for maintaining mitochondrial function and transcription.

The antennal transcriptome analysis and characterizations of odorant-binding proteins in Megachile saussurei (Hymenoptera, Megachilidae).

BACKGROUND: Odorant-binding proteins (OBPs) are essential in insect's daily behaviors mediated by olfactory perception. Megachile saussurei Radoszkowski (Hymenoptera, Megachilidae) is a principal insect pollinating alfalfa (Medicago sativa) in Northwestern China. The olfactory function have been less conducted, which provides a lot of possibilities for our research. RESULTS: Our results showed that 20 OBPs were identified in total. Multiple sequence alignment analysis indicated MsauOBPs were highly conserved with a 6-cysteine motif pattern and all belonged to the classic subfamily, coding 113-196 amino acids and sharing 41.32%-99.12% amino acid identity with known OBPs of other bees. Phylogenetic analysis indicated there were certain homologies existed among MsauOBPs and most sequences were clustered with that of Osmia cornuta (Hymenoptera, Megachilidae). Expression analysis showed the identified OBPs were mostly enriched in antennae instead of other four body parts, especially the MsauOBP2, MsauOBP3, MsauOBP4, MsauOBP8, MsauOBP11 and MsauOBP17, in which the MsauOBP2, MsauOBP4 and MsauOBP8 presented obvious tissue-biased expression pattern. Molecular docking results indicated MsauOBP4 might be the most significant protein in recognizing alfalfa flower volatile 3-Octanone, while MsauOBP13 might be the most crucial protein identifying (Z)-3-hexenyl acetate. It was also found the lysine was a momentous hydrophilic amino acid in docking simulations. CONCLUSION: In this study, we identified and analyzed 20 OBPs of M. saussurei. The certain homology existed among these OBPs, while some degree of divergence could also be noticed, indicating the complex functions that different MsauOBPs performed. Besides, the M. saussurei and Osmia cornuta were very likely to share similar physiological functions as most of their OBPs were clustered together. MsauOBP4 might be the key protein in recognizing 3-Octanone, while MsauOBP13 might be the key protein in binding (Z)-3-hexenyl acetate. These two proteins might contribute to the alfalfa-locating during the pollination process. The relevant results may help determine the highly specific and effective attractants for M. saussurei in alfalfa pollination and reveal the molecular mechanism of odor-evoked pollinating behavior between these two species.

Structural Similarities, in Relation with the Cross-Reactivity, of Hymenoptera Allergenic Dipeptidyl Peptidases IV-An Overall Comparison Including a New Dipeptidyl Peptidase IV Sequence from Vespa velutina.

(1) Background: Dipeptidyl Peptidases IV (DPPIVs), present in many organisms, are minor components in the venoms of Hymenoptera, where they have been identified as cross-reactive allergenic molecules. Considering that the structure of homologous DPPIVs is well characterized, we aimed to explain which regions have higher similarity among these proteins and present a comparison among them, including a new Vespa velutina DPPIV sequence. Moreover, two cases of sensitization to DPPIVs in wasp- and honeybee-sensitized patients are presented. (2) Methods: Proteomic analyses have been performed on the venom of the Asian hornet Vespa velutina to demonstrate the sequence of its DPPIV (allergen named Vesp v 3, with sequence accession number P0DRB8, and with the proteomic data available via ProteomeXchange with the identifier PXD046030). A comparison performed through their alignments and analysis of the three-dimensional structure showed a region with higher similarity among Hymenoptera DPPIVs. Additionally, ImmunoCAP™ determinations (including specific inhibition experiments), as well as IgE immunoblotting, are performed to demonstrate the allergenicity of Api m 5 and Ves v 3. (3) Results and Conclusions: The data presented demonstrate that the similarities among Hymenoptera DPPIVs are most likely localized at the C-terminal region of these enzymes. In addition, a higher similarity of the Vespa/Vespula DPPIVs is shown. The clinical cases analyzed demonstrated the allergenicity of Api m 5 and Ves v 3 in the sera of the allergic patients, as well as the presence of this minor component in the preparations used in venom immunotherapy.

Characterisation and localisation of plant metabolites involved in pharmacophagy in the turnip sawfly.

Several herbivorous insects consume certain metabolites from plants for other purposes than nutrition, such as defence. Adults of the turnip sawfly, Athalia rosae take up specific terpenoids, called clerodanoids, from Ajuga reptans. These metabolites are slightly modified by the sawflies and influence their mating behaviour and defence against predators. We characterised these metabolites and investigated their localisation in the insect and the specificity of the uptake and metabolite modification. Therefore, we performed feeding assays with adults and larvae of A. rosae as well as larvae of Spodoptera exigua, followed by chemical analyses. Two main clerodanoid-derived metabolites were detected in the abdomen and thorax but also on the surface of the adults. Small amounts were also found in larvae of the sawfly, while they were not detectable in S. exigua. Our findings provide new insights into the peculiarities of pharmacophagy and specialised metabolism in A. rosae.

Antennal transcriptome analysis of olfactory genes and characterizations of odorant binding proteins in two woodwasps, Sirex noctilio and Sirex nitobei (Hymenoptera: Siricidae).

BACKGROUND: The woodwasp Sirex noctilio Fabricius is a major quarantine pest worldwide that was first discovered in China in 2013 and mainly harms Pinus sylvestris var. mongolica Litv.. S. nitobei Matsumura is a native species in China and is closely related to S. noctilio. Recently, the two woodwasps species were found attacking the P. sylvestris var. mongolica Litv in succession. The olfactory system is the foundation of insect behavior. Olfactory genes were identified through antennal transcriptome analysis. The expression profiles odorant binding proteins (OBPs) were analyzed with RT-qPCR. RESULTS: From our transcriptome analysis, 16 OBPs, 7 chemosensory proteins (CSPs), 41 odorant receptors (ORs), 8 gustatory receptors (GRs), 13 ionotropic receptors (IRs), and one sensory neuron membrane protein (SNMP) were identified in S. noctilio, while 15 OBPs, 6 CSPs, 43 ORs, 10 GRs, 16 IRs, and 1 SNMP were identified in S. nitobei. Most of the olfactory genes identified in two species were homologous. However, some species-specific olfactory genes were identified from the antennal transcriptomes, including SnocOBP13, SnocCSP6, SnocOR26, SnocGR2, SnocIR7 in S. noctilio and SnitGR9, SnitGR11, SnitIR17 in S. nitobei. In total, 14 OBPs were expressed primarily in the antennae. SnocOBP9 and SnitOBP9, identified as PBP homologues, were sex-biased expression in two siricid, but with different pattern. SnocOBP11 and SnitOBP11 were highly expressed in antennae and clearly expressed in external genitalia. SnocOBP7 and SnitOBP7 were highly expressed in male genitalia. SnocOBP3 and SnocOBP10 were highly expressed in female genitalia and male heads, while SnitOBP3 and SnitOBP10 did not show obvious tissue bias. CONCLUSION: We analyzed 86 and 91 olfactory genes from S. noctilio and S. nitobei, respectively. Most of the olfactory genes identified were homologous, but also some species-specific olfactory genes were identified, which indicated the similarities and differences of the molecular mechanisms between the two closely-related species. Different expression in the antennae, external genitals or heads, exhibiting an obvious sex bias, suggested their different role in recognizing sex pheromones or plant volatiles. Species-specific expression for several OBPs genes may suggest that they strengthened or lost their original function during species differentiation, resulting in olfactory differences between the two species.

Interactions of Vank proteins from Microplitis bicoloratus bracovirus with host Dip3 suppress eIF4E expression.

Microplitis bicoloratus bracovirus (MbBV) inhibits the immune response of the host Spodoptera litura by disrupting nuclear factor (NF)-κB signaling and downstream gene expression. However, the underlying molecular mechanisms are not well understood. Herein, we report that viral ankyrin (Vank) proteins interacted with host dorsal-interacting protein 3 (Dip3) to selectively inhibit the transcription of eukaryotic translation initiation factor 4 E (eIF4E). Dip3 and Vank proteins were co-expressed and colocalized in the nucleus. Furthermore, ectopic expression of Dip3 rescued the transcription of some NF-κB-dependent genes suppressed by Vank proteins, including eIF4E. Co-immunoprecipitation and pull-down assays confirmed that Vank proteins interacted with and bound to full-length Dip3, which including MADF, DNA-binding protein, BESS, and protein-protein interaction motifs as well as non-motif sequences. In vivo, RNAi-mediated dip3 silencing decreased eIF4E levels and was accompanied by an immunosuppressive phenotype in S. litura. Our results provided novel insights into the regulation of host transcription during immune suppression by viral proteins that modulate nuclear NF-κB signaling.

Aphytis lepidosaphes (Hymenoptera: Aphelinidae) as an Effective Parasitoid for Controlling the Lepidosaphes tapleyi (Williams).

<b>Background and Objective:</b> The guava long scale insect <i>Lepidosaphes tapleyi</i> (Williams) (Hemiptera: Diaspididae) is considered one of the main destructive pests of guava around the world. Biological control represents a sustainable alternative for saving control of <i>L. tapleyi</i>. The main objective of the present work was to study the seasonal activity and evaluate the impacts of climatic factors on populations of the parasitoid, <i>Aphytis</i> <i>lepidosaphes</i>, during two successive years (2017/2018 and 2018/2019) in Esna district, Luxor Governorate, Egypt. <b>Materials and Methods:</b> Estimation of the relationship between the population density of <i>L. tapleyi</i> and <i>A. lepidosaphes</i> activity, by using different models of correlation and regression analyses. The estimate of the effects of climatic factors (daily mean max. temp., min. temp., mean of % relative humidity and mean of dew point) on seasonal activity of the parasitoid, <i>A. lepidosaphes</i>, during two successive years (2017/2018 and 2018/2019). <b>Results:</b> The results showed that the relationship between the population density of <i>L. tapleyi</i> and <i>A. lepidosaphes </i>activity was positive during both years. Furthermore, simple regression analysis indicated that the abundance of <i>A. lepidosaphes </i>was more highly correlated with the <i>L. tapleyi</i> population density in each whole year during the two successive years. The percentages of explained variance EV (%) indicated that all tested variables, i.e. daily mean maximum temperature, minimum temperature, relative humidity and dew point were responsible for 76.26 and 65.40% of the changes in parasitoid, respectively. Furthermore, the dew point was the most effective variable for the change in the parasitoid populations by 33.61 and 18.62%. <b>Conclusion:</b> The results showed that <i>A. lepidosaphes </i>had three peaks of seasonal abundance over the entire year. As well, the activity of <i>A. lepidosaphes</i> was more highly correlated with the <i>L. tapleyi </i>population size over the two successive years.

Proteomic investigation of Peristenus spretus ovary and characterization of an ovary-enriched heat shock protein.

Peristenus spretus (Hymenoptera: Braconidae) is one of the most important endoparasitoids used for biological control of the green mirid bug, Apolygus lucorum Meyer-Dür (Heteroptera: Miridae). However, what we know about its reproductive genetics is very limited. Here, the composition of ovarian proteins in P. spretus was analyzed. Mass spectrum data searched against the non-redundant NCBI protein and UniProt protein database identified 1382 proteins and revealed an enrichment of the heat shock protein 83 (HSP83) in P. spretus ovary. The Pshsp83 complete cDNA is 2175 bp in length and encodes a protein of 724 amino acids with a calculated molecular mass of 83.4 kDa and a theoretical isoelectric point of 4.87. Transcription of Pshsp83 appeared from days 1 to 13 post-emergence and peaked at 13th day. Immuno-localization showed that the HSP83 protein was present in cytoplasm of germarium and in egg chambers of the whole ovariole. The transcript abundance of Pshsp83 fluctuated drastically after heat shocks at different temperatures and the maximum emerged at 35°C. The exposure to 35°C caused no dramatic effects on reproductive parameters of adult females such as pupation rate, cocoon weight, emergence rate, sex ratio and developmental duration, but did on longevity. These results suggested that the HSP83 protein is involved in life-span regulation in the P. spretus.

Shedding Light on the Venom Proteomes of the Allergy-Relevant Hymenoptera Polistes dominula (European Paper Wasp) and Vespula spp. (Yellow Jacket).

Allergic reactions to stings of Hymenoptera species can have serious or even fatal consequences. If the identification of the culprit insect is possible, venom-specific immunotherapy effectively cures Hymenoptera venom allergies. Although component-resolved diagnostics has strongly evolved in recent years, the differentiation between allergies to closely related species such as Polistes dominula and Vespula spp. is still challenging. In order to generate the basis for new diagnostic and therapeutic strategies, this study aims at resolving the venom proteomes (venomes) of these species. The venoms of P. dominula and Vespula spp. (V. germanica, V. vulgaris) were analyzed by liquid chromatography-mass spectrometry. Resulting proteins were characterized regarding their function, localization and biochemical properties. The analyses yielded 157 proteins in Vespula spp. and 100 in P. dominula venom; 48 proteins, including annotated allergens, were found in both samples. In addition to a variety of venom trace molecules, new allergen candidates such as icarapin-like protein and phospholipase A2 were identified. This study elucidates the venomes of closely related allergy-eliciting Hymenoptera species. The data indicates that relying on marker allergens to differentiate between P. dominula and Vespula spp. venom allergy is probably insufficient and that strategies using cross-reactive major allergens could be more promising.

De Novo Transcriptome Identifies Olfactory Genes in Diachasmimorpha longicaudata (Ashmead).

Diachasmimoorpha longicaudata (Ashmead, D. longicaudata) (Hymenoptera: Braconidae) is a solitary species of parasitoid wasp and widely used in integrated pest management (IPM) programs as a biological control agent in order to suppress tephritid fruit flies of economic importance. Although many studies have investigated the behaviors in the detection of their hosts, little is known of the molecular information of their chemosensory system. We assembled the first transcriptome of D. longgicaudata using transcriptome sequencing and identified 162,621 unigenes for the Ashmead insects in response to fruit flies fed with different fruits (guava, mango, and carambola). We annotated these transcripts on both the gene and protein levels by aligning them to databases (e.g., NR, NT, KEGG, GO, PFAM, UniProt/SwissProt) and prediction software (e.g., SignalP, RNAMMER, TMHMM Sever). CPC2 and MIREAP were used to predict the potential noncoding RNAs and microRNAs, respectively. Based on these annotations, we found 43, 69, 60, 689, 26 and 14 transcripts encoding odorant-binding protein (OBP), chemosensory proteins (CSPs), gustatory receptor (GR), odorant receptor (OR), odorant ionotropic receptor (IR), and sensory neuron membrane protein (SNMP), respectively. Sequence analysis identified the conserved six Cys in OBP sequences and phylogenetic analysis further supported the identification of OBPs and CSPs. Furthermore, 9 OBPs, 13 CSPs, 3 GRs, 4IRs, 25 ORs, and 4 SNMPs were differentially expressed in the insects in response to fruit flies with different scents. These results support that the olfactory genes of the parasitoid wasps were specifically expressed in response to their hosts with different scents. Our findings improve our understanding of the behaviors of insects in the detection of their hosts on the molecular level. More importantly, it provides a valuable resource for D. longicaudata research and will benefit the IPM programs and other researchers in this filed.

Body distribution of toxic peptides in larvae of a pergid and an argid sawfly species.

Larvae of most Pergidae and Argidae (Symphyta: Tenthredinoidea) species contain toxic peptides such as pergidin and lophyrotomin. Here, larval hemolymph and organs of the pergid Lophyrotoma zonalis and the argid Arge pagana were analysed by liquid chromatography-tandem mass spectrometry. The major identified peptides were pergidin and 4-valinepergidin in L. zonalis, whereas pergidin and lophyrotomin in A. pagana. The storage period prior to chemical analysis was longer for the samples of the pergid than the argid species, which influenced peptide concentrations. In both species, however, the peptides occurred in decreasing order of concentration, first in the hemolymph, then in the integument, while minor amounts of the peptides were detected in other organs such as gut and fat body. By separating the cuticle of the pergid from the remaining integument, the peptides were found in equivalent amounts in each of these two body structures. The results suggest that the peptides play an important role in the defence of these sawfly larvae against predators.

Cloning and Immunosuppressive Properties of an Acyl-Activating Enzyme from the Venom Apparatus of Tetrastichus brontispae (Hymenoptera: Eulophidae).

Venom injected into the host plays vital roles in facilitating successful parasitization and development for parasitoid wasps, especially those devoid of polydnavirus, and the abundant venom proteins appear to be most likely involved in parasitization success. Previously, we found the four most abundant venom proteins, including 4-coumarate:CoA ligase-like 4 (4CL4-like), in the Tetrastichus brontispae (Hymenoptera: Eulophidae) venom apparatus. In this study, we cloned, expressed T. brontispae 4CL4-like (Tb4CL4-like) in Escherichia coli, and investigated its immunosuppressive properties. The deduced amino acid sequence for Tb4CL4-like shares high identity at conserved amino acids associated with the acyl-activating enzyme (AAE) consensus motif but shows only <40% identity with the members in the AAE superfamily. mRNA abundance analysis indicated that Tb4CL4-like was transcribed mainly in the venom apparatus. Recombinant Tb4CL4-like inhibited Octodonta nipae (Coleoptera: Chrysomelidae) pupal cellular encapsulation and spreading by targeting the hemocyte cytoskeleton and reduced the hemocyte-mediated phagocytosis of E. coli in vivo. Moreover, Tb4CL4-like exhibited greater affinity to palmitic acid and linolenic acid based on the molecular docking assay and is hypothesized to be involved in fatty acid metabolism. In conclusion, our results suggest that Tb4CL4-like may be an immunity-related AAE protein that is involved in the regulation of host immunity through fatty acid metabolism-derived signaling pathways.

Factors affecting the biology of Pachycrepoideus vindemmiae (Hymenoptera: Pteromalidae), a parasitoid of spotted-wing drosophila (Drosophila suzukii).

Pachycrepoideus vindemmiae is a wasp that parasitizes and host-feeds on pupae of the invasive spotted-wing drosophila (SWD, Drosophila suzukii). Few studies have addressed interactions between these two species and little is known about the potential of this parasitoid as a biocontrol agent of SWD and the different variables that may affect it. Here, we investigated the impact of extrinsic and intrinsic factors on life-history traits of P. vindemmiae. Both constant (entire adulthood) and limited (30 minutes) supplies of water + honey, honey, or host increased parasitoid survival compared to controls (water or fasting). Water + honey caused the highest parasitoid survivals (35-60 days), independent of supply period, sex, and host availability. Females were intrinsically more resistant to water- and honey-deprivation than males, and host-feeding elevated such resistance even higher. Constant honey supply (either with or without water) supported the highest host-killing capacities (= capacity to kill hosts) (ca. 600 SWD pupae/wasp). However, in young females (4-9 days old), the impact of honey availability (with or without water) was insignificant while water deprivation (either with or without honey) caused the highest host-killing potential. This indicates that although sugar becomes a critical nutritional resource as females age, young females depend more on water than sugar to reproduce. Neither water nor honey affected the sex ratio of young females, but when we considered the entire adulthood, the availability of honey caused the lowest proportion of females (0.50), independent of water availability. Neither water nor honey affected parasitoid emergence rate (0.97), independent of female age. Based on survival and host-killing capacity, we conclude that P. vindemmiae has a tremendous biocontrol potential against SWD. Both limited and constant supply of water, sugar, and host increase parasitoid survival, while constant supply of water and/or honey enhance its host-killing potential and decrease sex ratio depending on maternal age.

Identification and functional characterization of D-fructose receptor in an egg parasitoid, Trichogramma chilonis.

In insects, the gustatory system has a critical function not only in selecting food and feeding behaviours but also in growth and metabolism. Gustatory receptors play an irreplaceable role in insect gustatory signalling. Trichogramma chilonis is an effective biocontrol agent against agricultural insect pests. However, the molecular mechanism of gustation in T. chilonis remains elusive. In this study, we found that T. chilonis adults had a preference for D-fructose and that D-fructose contributed to prolong longevity and improve fecundity. Then, We also isolated the full-length cDNA encoding candidate gustatory receptor (TchiGR43a) based on the transcriptome data of T. chilonis, and observed that the candidate gustatory receptor gene was expressed from the larval to adult stages. The expression levels of TchiGR43a were similar between female and male. A Xenopus oocyte expression system and two-electrode voltage-clamp recording further verified the function analysis of TchiGR43a. Electrophysiological results showed that TchiGR43a was exclusively tuned to D-fructose. By the studies of behaviour, molecular biology and electrophysiology in T. chilonis, our results lay a basic fundation of further study on the molecular mechanisms of gustatory reception and provide theoretical basis for the nutritional requirement of T. chilonis in biocontrol.

Advertisement of unreceptivity - Perfume modifications of mason bee females (Osmia bicornis and O. cornuta) and a non-existing antiaphrodisiac.

Females of many monandrous insect species announce their receptivity either by specialised sex-pheromones or by a signature mixture of cuticular hydrocarbons (CHCs). The trigger that shuts down the sex-pheromone release or initialises a change in CHC bouquet is thought to be either the mating per se or male pheromones transferred during copulation. Besides a conversion of female volatiles, the application of antiaphrodisiacs, male derived pheromones that render mated females unattractive to competitors, is another strategy to protect females from further sexual chasings. This simple pattern becomes more complicated in the monandrous mason bees Osmia bicornis (syn: O. rufa) and O. cornuta due to a post-copulation phase in their mating sequence. Males display a stereotypic behaviour right after the intromission that induces females' unreceptivity. This post-copulatory display is predestined both to trigger a transition of the CHC profile and for the application of an antiaphrodisiac. However, the postulated antiaphrodisiac was not detectable even on freshly mated females. Moreover, the male's post-copulatory display did not trigger a change in the CHC bouquet and neither did the insemination. Instead the CHC profile of freshly emerged females changes into the bouquet of nesting females simply by age as an ontogenetic process in both Osmia species. This autonomous change in the CHC profile coincides with an age-specific decrease of young female's willingness to mate. How the resulting short period of female receptivity without back coupling by storage of sperm and the lack of an antiaphrodisiac fit into the behavioural ecology of the studied mason bee species is discussed.

Consequence of emergence pattern on inbreeding risk in the aphid parasitoid Aphidius matricariae (Hymenoptera: Braconidae).

In insect parasitoids, mating strategy depends on mate availability and is influenced by the spatial and temporal emergence patterns of adults. For quasi-gregarious species, simultaneous emergence favors local mating and reduces search costs for partners while increasing the risk of inbreeding, particularly when only one female parasitizes the initial host patch. Consequently, in inbreeding sensitive species, mating on the place of adult emergence (patch mating) between siblings should be counter selected. In practice, the timing of male and female emergence and of their dispersal influences mate availability and can limit on patch mating. To test the role of these two factors, we analyzed the daily distribution of emergence and patch residence time of a cohort in the aphid parasitoid Aphidius matricariae (Hymenoptera: Braconidae). We observed that adult emergence is concentrated on the morning with males emerging on average before females with some overlaps. A more precise evaluation of emergence pattern within a brood suggests that brothers and sisters rarely emerge at the same time and rapid dispersal of males and females favors off-patch mating. The relationships between timing of emergence including differences between sex and consequences on inbreeding probability in these species are thus discussed.

Combination of label-free quantitative proteomics and transcriptomics reveals intraspecific venom variation between the two strains of Tetrastichus brontispae, a parasitoid of two invasive beetles.

The venom apparatus is a conserved organ in parasitoids that shows adaptations correlated with life-style diversification. Combining transcriptomics and label-free quantitative proteomics, here we explored the venom apparatus components of the endoparasitoid Tetrastichus brontispae (Eulophidae), and provide a comparison of the venom apparatus proteomes between its two closely related strains, T. brontispae-Octodonta nipae (Tb-On) and T. brontispae-Brontispa longissima (Tb-Bl). Tb-Bl targets the B. longissima pupa as its habitual host. However, Tb-On is an experimental derivative of Tb-Bl, which has been exposed to the O. nipae pupa as host consecutively for over 40 generation. Results showed that approximately 1505 venom proteins were identified in the T. brontispae venom apparatus. The extracts contained novel venom proteins, such as 4-coumarate-CoA ligase 4. A comparative venom proteome analysis revealed that significant quantitative and qualitative differences in venom composition exist between the two strains; although the most abundant venom proteins were shared between them. The differentially produced proteins were mainly enriched in fatty acid biosynthesis and melanotic encapsulation response. Six of these enriched proteins presented increased levels in Tb-On, and this result was validated by parallel reaction monitoring (PRM) analysis. Overall, our data reveal that venom composition can evolve quickly and respond to host selection.

Toxic Peptides in Populations of Two Pergid Sawflies, Potential Biocontrol Agents of Brazilian Peppertree.

Determination of the safety of agents prior to release is one of the most important research goals in biological control. In addition to concerns for the safety of non-target plants, determination of the potential toxic properties of new agents needs to be assessed. Numerous phytophagous insects are defended by chemicals against the attack of natural enemies. Some of these defensive compounds could pose an environmental risk if an agent is released. Here, larval populations of two pergid sawflies, Heteroperreyia hubrichi and H. jorgenseni, were analyzed by LC-MS/MS to investigate whether they contain alleged toxic peptides. The first species is a potential candidate for biological control of the invasive weed Brazilian peppertree in Florida and Hawaii. The chemical analyses revealed the presence of the peptides pergidin (Perg), 4-valinepergidin (VPerg), dephosphorylated pergidin (dpPerg), lophyrotomin (LGln and LGlu). The effect of sawfly population for each species was significantly influencing peptide concentration. All peptides occurred at lower concentrations compared with purportedly toxic species of this sawfly family. However, the concentrations of the peptides are of concern for the welfare of wildlife and livestock that would be exposed to these species. These results demonstrate that release of this biological control agent in the invaded range may pose an environmental threat.

Scratching the Surface of an Itch: Molecular Evolution of Aculeata Venom Allergens.

Hymenopteran insects are infamous for their sting, and their ability to cause severe anaphylaxis and in some cases death. This allergic reaction is a result of allergens present in the venom. Hymenopterans have many common venom allergens, the most widespread of which include phospholipase A1, phospholipase A2, acid phosphatase, hyaluronidase, serine protease and antigen 5. While there have been studies that look at the phylogenetic histories of allergens within closely related species, to our knowledge, this is the first study using evolutionary analyses to compare across Hymenoptera the types of selection that are occurring on allergens. This research examined the publicly available sequences of six different groups of allergens and found that allergens had diverged and formed closely related clades which share greater sequence similarities. We also analysed the patterns of selection and found that they are predominately under the influence of negative selection.