Insecticide-induced hormesis in a factitious host, Corcyra cephalonica, stimulates the development of its gregarious ecto-parasitoid, Habrobracon hebetor

Sublethal phosphine fumigation induces transgenerational hormesis in a factitious host, Corcyra cephalonica

“…89 In the present study, phosphine-exposed C. cephalonica larvae nutrient (protein, lipid, and carbohydrate) reserves increased across generations only at LC 5 . These findings were consistent with previous studies 29,90 which found that sublethal deltamethrin and bistrifluron induced nutritional hormesis by increasing the total protein, lipid and carbohydrate contents in C. cephalonica and S. exigua, respectively. The protein contents were promoted transgenerationally, which was in accordance with Chen et al (2020), 91 who reported that the protein contents of vitellogenin (Vg) and its receptor (VgR) were significantly higher in later generations compared to earlier generations in Sogatella furcifera Horvath (Hemiptera: Delphacidae) under the influence of an insecticide, triflumezopyrim.…”

“…27 Insecticides at sublethal concentrations affect not only the insect pests, but also their natural enemies present in the surrounding environment. 28,29 Those effects include reduction in control efficiency of parasitoids, 30 affecting their foraging ability, 31 impairment in orientation and oviposition behaviour. 32 Chemicals that kill and harm insects at higher doses can stimulate certain biological processes in insects at lower doses.…”

“…33,34 This biphasic dose-response condition of high-dose inhibition and low-dose stimulation during or after toxicant exposure is called hormesis. 35 Several studies have reported that sublethal insecticide exposure could directly stimulate the population of several pest insects and natural enemies such as melon aphid, Aphis gossypii Glover (Hemiptera: Aphididae), 36 brown planthopper, Nilaparvata lugens Stal (Hemiptera: Delphacidae), 37 black cutworm, Agrotis ipsilon Hufnagel (Lepidoptera: Noctuidae), 38 diamondback moth, Plutella xylostella Linnaeus (Lepidoptera:Plutellidae), 39 Habrobracon hebetor Say (Hymenoptera: Braconidae), 29 and Trichogramma parasitoids (Hymenoptera: Trichogrammatidae). 40,41 Even though a few studies have acknowledged the significance of the sublethal effects of insect pest species to fumigants, [42][43][44] there is a paucity of knowledge on this topic.…”

Functional response of an egg parasitoid,Trichogramma chilonisIshii to sublethal imidacloprid exposure

“…The rearing of the host insect Corcyra cephalonica was carried out according to the procedure of Gowda et al 47 . 0.25 cc (approximately 5000) Corcyra cephalonica eggs were charged in a medium consisting of sterilized and insecticide free broken maize kernels (2.5 kg), roasted groundnut powder (50 g), yeast (2 g), multivitamin powder (5 g), streptomycin sulfate (0.2 g) and formalin (0.1%, 10 mL).…”

“…The rearing of the host insect Corcyra cephalonica was carried out according to the procedure of Gowda et al 47 0.25 cc (approximately 5000) Corcyra cephalonica eggs were charged in a medium consisting of sterilized and insecticide free broken maize kernels (2.5 kg), roasted groundnut powder (50 g), yeast (2 g), multivitamin powder (5 g), streptomycin sulfate (0.2 g) and formalin (0.1%, 10 mL). Upon emergence of the adults, they were collected in a moth collection unit (50 L) consisting of an inner oviposition chamber (10 L) and base unit covered with wire mesh (15 mesh size) for the deposition of eggs.…”