Recent years have seen a marked increase in our awareness of the need to incorporate greater physiological realism into studies of parasitoid behaviour and population dynamics. Quanti¢cation of the number of eggs produced as a result of a host-feeding event, the host-feeding gain, is essential for predicting when a parasitoid should bypass an opportunity for current reproduction (i.e. laying eg...

It has been reported that the aphelinid wasp Eertmocerus mundus parasitizes all four nymphal instars of the sweet potato whitefly, Bemisia tabaci (Biotype B), with 3rd instars being the preferred hosts. The parasitoid lays its egg on the leaf underneath the host nymph. First instars hatch and later penetrate the whitefly. Previous studies have shown that the initiation of parasitoid penetration...

Observed changes in mean temperature and increased frequency of extreme climate events have already impacted the distributions and phenologies of various organisms, including insects. Although some research has examined how parasitoids will respond to colder temperatures or experimental warming, we know relatively little about how increased variation in temperature and humidity could affect int...

Insect parasitoids and herbivores must balance the risk of egg limitation and time limitation in order to maximize reproductive success. Egg and time limitation are mediated by oviposition and egg maturation rates as well as by starvation risk and other determinants of adult lifespan. Here, we assessed egg load and nutritional state in the soybean aphid parasitoid Binodoxys communis under field...

the parasitoid trichogramma brassicae bezdenko is used for inundative releases in biological control programs against lepidopteran pests in agro-ecosystems. age-specific functional responses of t. brassicae to different egg densities (5, 10, 20, 30, 40, 60, and 80) of sterilized eggs of ephestia kuehniella at 23±1°c, 60±5% rh, and 16:8 h (l:d photoperiod ) were studied. e. kuehniella densities ...

Plants can recruit parasitic wasps in response to egg deposition by herbivorous insects-a sophisticated indirect plant defense mechanism. Oviposition by the Large Cabbage White butterfly Pieris brassicae on Brussels sprout plants induces phytochemical changes that arrest the egg parasitoid Trichogramma brassicae. Here, we report the identification of an elicitor of such an oviposition-induced p...

Animals should increase their present reproductive output if their chances for future reproduction are low. However, an animal's ability to make this adjustment may be constrained by the physiological mechanisms mediating the response. To examine this hypothesis, I infected 2- and 5-week-old female crickets, Acheta domesticus, with either a pathogen (the bacterium Serratia marcescens) that indu...

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...

Parasitoids are among the most important natural enemies of insects in many environments. Acyrthosiphon pisum, the pea aphid, is a common pest of the leguminous crops in temperate regions. Pea aphids are frequently attacked by a range of endoparasitic wasps, including the common aphidiine, Aphidius ervi. Immunity to parasitoid attack is thought to involve secondary symbiotic bacteria, the prese...