Oviposition Behaviour and Clutch Size in a Group-Feeding Pyralid Moth, Omphalocera munroei

Abstract

JSTOR is a not-for-profit service that helps scholars, researchers, and students discover, use, and build upon a wide range of content in a trusted digital archive. We use information technology and tools to increase productivity and facilitate new forms of scholarship. For more information about JSTOR, please contact support@jstor.org.. British Ecological Society is collaborating with JSTOR to digitize, preserve and extend access to Journal of Animal Ecology. SUMMARY(1) Insects that lay their eggs in groups can influence the success of their offspring not only by selectively laying eggs on hosts of high quality, but also by adjusting the number of eggs that they place on hosts.(2) The oviposition behaviour of females of the pyralid moth, Omphalocera munroei, leads them to vary the number of eggs placed on their food plants in the genus Asimina in such a way as to reduce the impact of within-species competition.(3) Plants with many leaves are more likely to have eggs laid on them, receive larger clutches, and receive more clutches than plants with few leaves.(4) The number of eggs placed on a plant more closely reflects the carrying capacity of the plant when natural mortality rates are taken into consideration than it does the carrying capacity in the absence of mortality.(5) The overall effect of the oviposition behaviour of 0. munroei is to reduce substantially the likelihood that the moth larvae will be forced to abandon the plant before they complete development, thus increasing their chances of survival to reproduction.

Induced responses in Nicotiana attenuata affect behavior and growth of the specialist herbivore Manduca sexta

“…First, as we have shown in this paper, the herbivore can enhance its fitness by finding another uninduced plant on which to feed. Second, the risk associated with leaving its food plant decreases as searching efficiency increases and risk of mortality decreases with increasing body mass (Damman 1991;Dyer 1995). At the same time, staying on an induced plant as it becomes more resistant decreases larval fitness.…”

Importance of larval migration (dispersal) for the survival of Ascia monuste (Godart) (Lepidoptera: Pieridae)

“…Ascia monuste (Godart)] not only choose an oviposition site but may also determine how many eggs to lay. This "decision" represents a compromise between factors favouring large group size and the number of offspring that the patch can support (Damman 1991). Larval migration (dispersal) is presumably an adaptive behavior aimed at enhancing survival of larval with limited food resources and is common when there are more larvae than a single plant can sustain (Chapman et al 1983, Berger 1992.…”

Aggregative feeding of pipevine swallowtail larvae enhances hostplant suitability

“…Fisher (1930) first proposed this idea, suggesting that group feeding of aposematic Lepidoptera could be explained through kin selection. Other hypotheses about the adaptive significance of aggregative feeding in the Lepidoptera include thermoregulation (Porter 1982;Bryant et al 2000), active group defense (Stamp 1980;Wilson 1980;Fitzgerald 1993), feeding facilitation (Chew and Robbins 1984;Denno and Benrey 1997), a cost reducing strategy for maintaining mutualists (AxØn and Pierce 1998), overcoming plant structural defenses or leaf toughness (Rathcke and Poole 1975;Young and Moffett 1979;Clark and Faeth 1997), and maximizing resource use (Damman 1991;Le Masurier 1994). Alternatively, aggregative feeding may be a non-adaptive consequence of large clutch size resulting from female egg load or ecological pressures on gravid females to maximize their realized fecundity (Courtney 1982(Courtney , 1984Tatar 1991).…”