Relationship Between Behavior and Physiology in an Invasive Pest Species: Oviposition Site Selection and Temperature-Dependent Development of the Oriental Fruit Moth (Lepidoptera: Tortricidae)

Abstract

Oviposition site selection is crucial for the reproductive success of a herbivore insect species with relatively sedentary larvae. The optimal oviposition theory, i.e., the preference-performance hypothesis, has thus far mainly been tested with a focus on nutritional quality of the host. This study investigates whether female oriental fruit moth Grapholita (Cydia) molesta choose a microhabitat for oviposition characterized by a temperature range within which their offspring perform best. Thermal preferences of females during oviposition were assessed in a circular temperature gradient arena. Offspring performance and survival were assessed under different constant temperature conditions. Females preferred oviposition sites of ϳ30ЊC over lower and higher temperatures. At this temperature, egg, larval, and pupal development was signiÞcantly faster than at 22 and 25ЊC, and larval development was also faster than at 33ЊC. At 30ЊC and at the lower temperatures tested, survival of eggs and larvae was signiÞcantly higher than at 33ЊC, whereas development was precluded at 35ЊC. Furthermore, female pupal weight attained at 30 and 33ЊC exceeded that reached at the lower temperatures tested. Considering the potentially reduced predation risk caused by the shorter developmental time of eggs and larvae, the laboratory data suggest that this species maximizes its Þtness by selecting a thermally optimal environment for its offspring, supporting the optimal oviposition theory. Conversely, it is known that the codling moth (C. pomonella) lacks a mechanism to avoid temperatures lethal to progeny development, which may reßect the differences in geographic ranges of these tortricids.

Chromosomal Evolution in Tortricid Moths: Conserved Karyotypes with Diverged Features

“…A laboratory culture of Grapholita molesta was obtained from Beatrice Christoffel and Silvia Dorn (Applied Entomology, Institute of Agricultural Sciences, ETH Zürich, Switzerland). The culture was established from a wild population collected in orchards in the province Emilia Romagna, Italy (see [43]). For G. molesta , we used the same diet and rearing conditions as for the codling moth.…”

Effects of Temperature on Mate Location in the Planthopper,Nilaparvata lugens(Homoptera: Delphacidae)

“…Global warming can affect insect herbivores directly, through impacts on their physiology and behavior, or indirectly, where they respond to climate-induced changes mediated through other factors, notably the host plant (Bale et al 2002, Notter-Hausmann andDorn 2010).…”

Ability of the Oriental Fruit Moth Grapholita molesta (Lepidoptera: Tortricidae) to Detoxify Juglone, the Main Secondary Metabolite of the Non-host Plant Walnut

“…Larval developmental time was recorded as the number of days from introduction of the larva onto the diet until its entry into the cardboard strip for pupation. Pupal developmental time was recorded as the period between larval entry into the cardboard strip and adult emergence, thus including any non-feeding prepupal stage the larva may have undergone (Notter-Hausmann and Dorn, 2010;Piskorski and Dorn, 2011). Larval survival was assessed as the proportion of individuals that entered the cardboard strip in relation to those that had been introduced as first-instar larvae.…”