Callosobruchus embryo struggle to guarantee progeny production

Abstract

We conducted a series of experiments to test insect embryo capability to survive and increase reproductive investment during early development after short exposure to essential oils. We used Callosobruchus maculatus as a model insect and eucalyptus leaf and flower essential oils. Both essential oils exhibited toxicity against C. maculatus embryos and adults. However, flower essential oil was more toxic. A fetus exposed to essential oils tried to make the best of a bad situation and compensate essential oils harmful effects in the later life stages. Insect progeny production guarantee resulted in a trade-off between reproduction and female longevity. The insect also could alter fitness and reproductive behavior including, mating latency reduction, copulation duration increase, and copulation success rate raise in adulthood. Flower essential oil-exposed embryos were more successful in increasing copulation duration, and leaf essential oil-exposed embryos achieved more copulation success and less mating latency. These consequences persisted until F1 generation that was not directly exposed to essential oil. However, the F2 generation could concur with the harmful effects of essential oils. C. maculatus embryo might use epigenetic mechanisms to guarantee progeny production. Reproductive behavior changes and the trade-off can be evolutionary mechanisms to save species from possible extinction in deleterious situations.

Effect of alcoholic phenol and nanocapsules extract from grape seed (Vitis vinifera) on egg hatching and adult death of southern cowpea beetles

“…The lower incidence of hatching Callosobruchus maculatus may be caused by the extract preventing air from entering the egg and thus preventing the fetus from breathing [13,14,15,16].…”

Callosobruchus larval competition and its consequences for male and female adults

“…Each pair was given 10 min to initiate mating. Next, we recorded the mating parameters, such as the first attempt by the male to start mating, mating latency, kicking initiation by the female and its duration, and mating termination time (Amiri & Bandani, 2020). We called the first attempt the interval between placing the beetle in the dish and the first mating attempt by the male.…”

“…When adults emerge, they leave the seed and live freely (Guedes et al, 2007; Vamosi, 2005). Also, C. maculatus , as a facultative aphagous insect, does not require feeding or drinking as adults for successful reproduction, so the effects of larval status on adult fitness can be considered separately through experimentation (Amiri & Bandani, 2020; Wagner & Bakare, 2017).…”

Callosobruchus maculatus males and females respond differently to grandparental effects

“…They quickly evaporate at room temperature. Plant essential oils and active ingredients have the potential to show remarkable bioactivity against a variety of insects, including the cowpea weevil Callosobruchus maculatus, which has repellent, contact, fumigant toxicity, ovicidal activity, oxidative stress, or susceptibility-enhancing properties [27][28][29][30][31][32][33]. Essential oil's chemical composition is linked to its toxicity to insects.…”

“…maculatus (2.0-3.5 mm long) is a significant pest of cowpeas and other legumes distributed throughout the tropics and sub-tropics. Adults are facultative aphagous short-lived insects (around one to two weeks) that do not need to feed or drink [31,40]. After mating, female C. maculatus deposits eggs on the legume seed surface.…”