Impact of starvation on immune defense and other life- history traits of an outbreaking geometrid, Epirrita autumnata: a possible causal trigger for the crash phase of population cycle
نویسندگان
چکیده
Outbreaking populations of the autumnal moth, Epirrita autumnata, are regularly facing a shortage of food and starvation. We found that starvation led to a prolonged larval development and a marked reduction in pupal weights. A decrease in female pupal weight caused a 50% decrease in the realized fecundity. Due to starvation the melanotic encapsulation rate decreased but the activity of PO — a key enzyme in the melanotic pathway that may indicate scarcity of PO substrates due to starvation — increased. Our results suggested that the shortage of food during high-density years reduce markedly the fecundity of E. autumnata, and may also reduce the ability of the autumnal moth to resist parasitoids and pathogens. Altogether, starvation may potentially destabilize the pathogen dynamics of insects and may be a proximate reason for moth population crashes.
منابع مشابه
Discovery of continental-scale travelling waves and lagged synchrony in geometrid moth outbreaks prompt a re-evaluation of mountain birch/geometrid studies
The spatio-temporal dynamics of populations of two 9-10 year cyclic-outbreaking geometrids, Operophtera brumata and Epirrita autumnata in mountain birch forests in northern Fennoscandia, have been studied since the 1970´s by a Swedish-Norwegian research team and, during the last decade, by Norwegian and Finnish research teams. Some of the early results have been challenged by the Norwegian team...
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