Starvation is a complex physiological state that induces changes in protein expression to ensure survival. The insect midgut is sensitive to changes in dietary content as it is at the forefront of communicating information about incoming nutrients to the body via hormones. Therefore, a DIA proteomics approach was used to examine starvation physiology and, specifically, the role of midgut neuropeptide hormones in a representative lepidopteran, Manduca sexta. Proteomes were generated from midguts of M. sexta fourth-instar caterpillars, starved for 24 h and 48 h, and compared to fed controls. A total of 3047 proteins were identified, and 854 of these were significantly different in abundance. KEGG analysis revealed that metabolism pathways were less abundant in starved caterpillars, but oxidative phosphorylation proteins were more abundant. In addition, six neuropeptides or related signaling cascade proteins were detected. Particularly, neuropeptide F1 (NPF1) was significantly higher in abundance in starved larvae. A change in juvenile hormone-degrading enzymes was also detected during starvation. Overall, our results provide an exploration of the midgut response to starvation in M. sexta and validate DIA proteomics as a useful tool for quantifying insect midgut neuropeptide hormones.

Several mosquito species within the genus Anopheles are vectors for human malaria, and the spread of this disease is driven by the propensity of certain species to feed preferentially on humans. The study of olfaction in mosquitoes is important to understand dynamics of host-seeking and host-selection; however, the majority of these studies focus on Anopheles gambiae or An. coluzzii, both vectors of malaria in Sub-Saharan Africa. Other malaria vectors may recognize different chemical cues from potential hosts; therefore, in this study, we investigated An. stephensi, the south Asian malaria mosquito. We specifically focused on the mouthparts (primarily the maxillary palp and labella) that have been much less investigated compared to the antennae but are also important for host-seeking. To provide a broad view of chemoreceptor expression, RNAseq was used to examine the transcriptomes from the mouthparts of host-seeking females, blood-fed females, and males. Notably, AsOr8 had a high transcript abundance in all transcriptomes and was, therefore, cloned and expressed in the Drosophila empty neuron system. This permitted characterization with a panel of odorants that were selected, in part, for their presence in the human odor profile. The responsiveness of AsOr8 to odorants was highly similar to An. gambiae Or8 (AgOr8), except for sulcatone, which was detected by AsOr8 but not AgOr8. Subtle differences in the receptor sensitivity to specific odorants may provide clues to species- or strain-specific approaches to host-seeking and host selection. Further exploration of the profile of An. stephensi chemosensory proteins may yield a better understanding of how different malaria vectors navigate host-finding and host-choice.

Natural Control of Peach Leaf Curl Aphid, Brachycaudus Helichrysi (Kaltenbach) (Hemiptera: Aphididae) by Oomyzus scaposus (Thomson) (Hymenoptera: Eulophidae) on Peach

Social isolation is known to cause a variety of behavioural abnormalities in many different species. Here we perform a detailed behavioural analysis of how chronic social deprivation alters behaviours in the fruit fly, Drosophila melanogaster, within an arena. We identify specific, quantifiable measures to capture behaviours of interest using the previously established cTrax and MATLAB BehavioralMicroarray toolkits. Socially isolated Drosophila exhibited behavioural changes in almost all measures assessed, identifying a surprisingly wide range of behavioural deficits. We observe that both male and female isolated flies demonstrate reduced locomotion (walk distance and speed), are more avoidant of other same-sex individuals (increased social distancing), and show reduced clustering into same-sex groups. Because these measures of sociality are assessed in same-sex groups, they are independent of sexual motivations. For the majority of measures taken, we observe the same behavioural changes in isolated male and female flies. In the brain, we observe that social isolation leads to a reduction in synaptic proteins specifically within dopamine neurons, as well as across the whole brain in both sexes, consistent with the varied behavioural abnormalities observed upon social isolation.