Influence of Generation and Photoperiod on Larval Development ofLobesia botrana(Lepidoptera: Tortricidae)

Abstract

The influence of generation (under field conditions) and photoperiod (under laboratory conditions) on Lobesia botrana larvae development was studied. Some larvae were collected during three annual generations in two grape-growing areas of northeastern Italy, and others were individually reared in the laboratory from egg to pupa on an artificial diet under two different photoperiod conditions (respectively, daylight 16 h/d [long day {LD}] and 14 h/d [short day {SD}]). The mandible lengths of collected larvae were measured and the data analyzed morphometrically to determine the number of larval instars. In the laboratory study, the number of larval moultings, the mandible length of each instar, the development time from hatching larva to pupa, and the pupal weight were considered. The measurement of mandible lengths of larvae collected in the field indicated the existence of five larval instars in all three annual generations, but the size of the two oldest larval instars was significantly higher for third-generation larvae than for the previous generations. Under laboratory conditions, the larvae usually exhibited five instars, but the mandible lengths of larvae and the pupa size were greater for individuals reared under SD. These also took a greater number of days to develop from hatching larvae to pupae. Because a larger size of the final larval instar occurs in individuals that produce diapausing pupae under SD in both the laboratory and the field, a positive association between larval size and the probability of surviving the winter can be inferred.

Artificial light at night causes diapause inhibition and sex‐specific life history changes in a moth

“…The initiation of pupal diapause in moths is strongly dependent on temperature and light conditions during the larval stage (Adkisson 1966;Roditakis and Karandinos 2001;Huang et al 2005;He et al 2009;Pavan et al 2010;Xiao et al 2010;Xu et al 2014). We found very large differences in the duration of the pupal stage, with a vast majority of moths subjected to green and white artificial light as larva emerging earlier from the pupa than moths in darkness ( Fig.…”

A review of climate-driven mismatches between interdependent phenophases in terrestrial and aquatic ecosystems

“…Lobesia botrana is a moth the larvae of which feed on grapevine flowers and berries, an activity which results in a decrease in final crop yield. It has a facultative diapause and a variable number of generations per year, depending on temperature and photoperiod (Pavan et al 2010). It is usually reported as being trivoltine in Mediterranean areas, although, in the warmest years, a fourth partial flight has been reported (Torres-Vila et al 2004).…”

Is the existence of a mutualistic relationship between Lobesia botrana and Botrytis cinerea well‐founded?

“…In Experiments II and III the number of larval instars (established on the basis of the number of head capsules collected after molting) and larval mandible lengths (as a parameter of larval size) were recorded for each individual. After each molting, exuvial head capsules were mounted individually on slides in Berlese's liquid and the left mandible was measured to a precision of 1.25 μm using a calibrated ocular micrometer under an optical microscope at 400× magnification (Zeiss Axioplan; Pavan, Floreani, Barro, Zandigiacomo, & Dalla Montà, 2010). Pupae were weighed with a precision balance (Sartorius CP2P: capacity 2.1 g; readability 0.001 mg).…”