Female golden egg bugs show unique flexibility in their oviposition behavior. Females can lay eggs on plants, where they are left unattended, or on the back of conspecifics, where they remain until hatching. In this article we show that eggs have greater survival rates when carried by an adult than when laid on plants. The main causes of egg mortality are predators and a parasitoid wasp. Our re...

We compared biological functions of two acetylcholinesterase genes (TcAce1 and TcAce2) in Tribolium castaneum, a globally distributed major pest of stored grain products and an emerging model organism, by using RNA interference. Although both genes expressed at all developmental stages and mainly in the brain, the transcript level of TcAce1 was 1.2- to 8.7-fold higher than that of TcAce2, depen...

effect of five soybean varieties (sahar, jk, bp, williams and l17) on life cycle and fecundity of the beet armyworm, spodoptera exigua (hã¼bner) was evaluated at temperature of 25 â± 1â°c, 60 â± 5% r.h. and a photoperiod of 16: 8 (l: d) h. the preimaginal development period of males and females was longest on l17 (30.17 â± 0.28 and 29.63 â± 0.23 days) and shortest on bp and sahar. the adult lon...

Reacting to a threat before physical contact, e.g., induced by air- or water-borne substances, appears to be an elegant way of defense. The reaction may be behavioral, developmental, morphological, or physiological, and it can involve a shift in niche or life history. Hatching from eggs is a shift in niche and in life history. From niche shift and life history models, one would predict that the...

1. Offspring from older parents often have shorter adult lifespans than offspring of younger mothers. We examine the effects of offspring genotype, maternal age and paternal age on offspring survival, development and adult lifespan in the seed beetle, Callosobruchus maculatus . 2. Females took about a quarter of a day longer to develop from an egg to an adult and lived ≈ 7 days longer than male...

Mothers should adjust the size of propagules to the selective forces to which these offspring will be exposed. Usually, a larger propagule size is favored when young are exposed to high mortality risk or conspecific competition. Here we test 2 predictions on how egg size should vary with these selective agents. When offspring are cared for by parents and/or alloparents, protection may reduce th...