Thermoregulation behaviour in codling moth larvae

Abstract

The thermoregulation behaviour of the codling moth, Cydia pomonella, is investigated in temperature gradient experiments with larvae feeding within apples, and with mature larvae searching for cocooning sites. Feeding larvae appear to prefer the apple hemisphere with a higher temperature (i.e. they build larger cavities in the radiated, warmer part of the fruit). The proportion of larval cavities in the warmer hemisphere is positively related to increasing apple temperature on that side, as well as to the temperature difference between the warm and the cool fruit hemisphere. The mechanism in feeding larvae can be termed as cryptic basking because, during microhabitat selection, the caterpillars exploit temperature differences that are caused explicitly by incident solar radiation. Fifth-instar larvae in search of cocooning sites show no temperature preference within the large gradient offered (9-29 C), with no difference between males and females. During larval development, the insect changes its thermoregulation behaviour in response to a possible shift in benefits of an elevated body temperature with respect to environmental conditions. Both the thermoregulation behaviour and such a shift of behavioural response should be respected when simulating body temperatures of the species.

Parasitism cost of living in a high quality habitat in the bog fritillary butterfly

“…They are intimately linked in the field in the way they define the suitable micro-environment for the species. Some vegetation features, such as vegetation height and structural complexity, are known to influence the incidence of caterpillars in some butterfly species (Anthes et al 2003;Betzholtz et al 2007), while microclimate is important for caterpillar development (Alonso 1997;Kuhrt et al 2005). Boloria eunomia is an ectothermic glacial relict species and accordingly depends upon precise thermal microenvironments to attain and/or maintain optimal body temperatures.…”

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

“…Insect body temperature can be regulated behaviorally, particularly by microhabitat selection (Casey 1976, Kü hrt et al 2005. Active microhabitat selection is not possible for immobile stages such as eggs, and therefore, a femaleÕs choice of oviposition site can have a major impact on the Þtness of her offspring (Rosenzweig 1991).…”

“…It leads to the choice of thermally favored microclimates, especially of sunny or shaded substrates (May 1979). Such temperature selection behavior has been reported for a number of lepidopteran (Casey 1976, Kü hrt et al 2005) and coleopteran species (May 1982, Kreuger and Potter 2001, Hausmann et al 2005. Thermal orientation may lead the adult female to an optimal environment for development of her progeny, but, as mentioned above, there may be exceptions.…”

“…Studies on the response of the oriental fruit moth to changing abiotic conditions (Hughes et al 2004) indicate a high potential for adaptation. However, in contrast to the codling moth C. pomonella (Kü hrt et al 2005(Kü hrt et al , 2006, little is known on the thermal response of the oriental fruit moth, despite its high economic signiÞcance (Natale et al 2003, IlÕichev et al 2004, Evenden and McClaughlin 2005.…”

“…Thermal preference of females during oviposition was assessed using a circular temperature gradient arena, which prevents any edge effects (Kü hrt et al 2006). Performance of the offspring was studied under controlled conditions (Summers et al 1984, Kü hrt et al 2005 at different constant temperatures, thus potentially providing comparable insight into population dynamics of particular species. In view of the documented sensitivity to abiotic cues and the relatively sedentary behavior of the feeding larvae (Scheirs and De Bruyn 2002), the oriental fruit moth was considered a promising candidate for testing the oviposition preferenceÐ offspring performance hypothesis.…”