The shield bug, Graphosoma lineatum (Heteroptera, Pentatomidae), harbors extracellular Pantoea‐like symbiont in the enclosed crypts of the midgut. The symbiotic bacteria are essential for normal longevity and fecundity of this insect. In this study, life table analysis was used to assess the biological importance of the gut symbiont in G.?lineatum. Considering vertical transmission of the bacterial symbiont through the egg surface contamination, we used surface sterilization of the eggs to remove the symbiont. The symbiont population was decreased in the newborn nymphs hatched from the surface‐sterilized eggs (the aposymbiotic insects), and this reduction imposed strongly negative effects on the insect host. We found significant differ

Plant secondary metabolites influence the feeding in insects through several modes of action. In this study, the physiological effects of erucin isothiocyanate were investigated on the elm leaf beetle?Xanthogaleruca luteola?(M?ller) (Coleoptera: Chrysomelidae) via impact on crustacean cardioactive peptide (CCAP) and midgut digestive enzymes. Third instar larvae of elm leaf beetle were fed on leaves impregnated with erucin for three days. The results showed that erucin decreased?α-amylase, lipase, and protease release. Western blot analysis and competitive ELISA showed that erucin decreased CCAP content of the midgut, brain, and hemolymph. Moreover, incubation of dissected midgut with CCAP and also its injection into the hemocoel increased

The pistachio green stink bug, Brachynema germari Kolenati (Hemiptera: Pentatomidae), is one of the most important pests of pistachio nuts in many pistachiogrowing regions in Iran. This insect harbors a gammaproteobacterial symbiont, related to the genus Pantoea, in the numerous crypts of its posterior midgut, which is vertically transmitted by infection of the egg masses and orally acquired by newborn nymphs. In the present study, the effects of the symbiont on host morphology, emergence rates, and mating frequency of B. germari were explored. For this purpose, two symbiont elimination strategies, high temperature and egg surface sterilization, were used and their effects were compared. We found external morphological changes (eg abnormali

The box tree moth (BTM), Cydalima perspectalis and the fall webworm (FWW), Hyphantria cunea are two invasive pests of forest trees that have been recorded from Hyracinan forests in north Iran for the first time in 2016 and 2002, respectively. In a search for tentative native entomopathogenic nematode species (EPNs) with potential biocontrol ability against lepidopteran pests of forest trees in north Iran, Oscheius myriophilus was isolated by soil-baiting method from forests of Amlash in the east of Gilan province. The Iranian isolate of this species is characterized by 870–1,247 μm long hermaphrodites having 17–20 μm long stoma, vulva at 45.5–53.1% of body length, tail 90–126 μm long, common males with 38–49 μm long spicules a

In this study, the biological activities and mode of action of 3-butylidene phthalide (3-BPH) were studied. 3-BPH had a superior efficiency against microsclerotia of Macrophomina phaseolina compared to the commercial fungicide tricyclazole. The microsclerotia formation and pigmentation were inhibited at 100 μg/mL. Moreover, the fungicide exhibited in silico affinity toward trihydroxy naphthalene reductase (3HNR). Both 3-BPH and tricyclazole showed congruence in the orientation and interaction within the 3HNR active site. 3-BPH displayed a strong interaction with SER-164, TYR-178, and TYR-223, with estimated binding energy and inhibition constant of −6.78 kcal mol−1, and Ki = 12.6 μM, respectively. Furthermore, it showed in

The diamondback moth, Plutella xylostella (L.)(Lepidoptera: Plutellidae) is one of the most destructive insect pests, feeding exclusively on wild and cultivated cruciferous species. The attacked plants produce considerable amount of glucosinolates in response to insects’ feeding. Herein, we studied digestive activities of P. xylostella on four different genotypes of family Brassicaceae including two canola cultivars (SLM046 and RGS003) and two cabbage cultivars (Green-Cornet and Glob-Master). The highest proteolytic and amylolytic activities of P. xylostella were observed on Green-Cornet and the lowest occurred on RGS003 and Glob-Master, respectively. The highest activity of α-glucosidase and β-glucosidases were observed on Green-Cornet

Gut microbiota modulates various physiologic processes in insects, such as nutrition, metabolic homeostasis, and pathogen exclusion. Maintaining a normal microbiome is an essential element of the gut homeostasis, requiring an extensive network of regulatory immune responses. The molecular mechanisms driving these various effects and the events leading to the establishment of a normal microbiota in insects are still largely unknown. In this study, the NF-kB (IMD and Toll) signaling pathways in the gut of Galleria mellonella and their roles in the regulation of its gut microbes were assessed. For this, the transcript levels of the IMD pathway (Imd and Relish) and the Toll pathway (Sp?tzle and Dif/Dorsal) genes were analyzed and the results sh

This study determined the effects of cold storage of mummies on the biological characteristics of Aphidius colemani Viereck (Hymenoptera Braconidae), a solitary, koinobiont endoparasitoid of more than 40 species of aphids. The effects of three constant temperatures (5, 7 and 9 C) at five time periods (5, 10, 15, 20 and 30 days) were evaluated on eight quality control parameters of the parasitoid (adult emergence, sex ratio, time elapse before emergence, adult longevity, length of the hind tibia, flight capacity, percent parasitism and sex ratio of F1 wasps). The results showed that all parameters except the sex ratio of F1 were negatively affected by cold storage duration in comparison to control treatment (25 C). Based on the adult emergen

Trypsin is the major protease enzyme existing in the midgut of most insect species. Despite the importance of trypsin enzymes in insects, there is no comprehensive evidence available on the structure and function of this enzyme. Therefore, in the present study, trypsin enzymes from different species including insect and other organisms were analyzed using bioinformatics approaches. Ten motifs were found by MEME and MAST tools, which similarly existed in all various insect species. Moreover, the phylogenetic study revealed a high similarity among the insect trypsins, suggesting that they might have derived from a common ancestor. To understand the characteristics of insect trypsins, including active binding site structure, a reliable structu