Agricultural and Forest Entomology (2013) 15, 398-406

Francesco Pavan, Chiara Floreani, Paola Barro, Pietro Zandigiacomo and Laura Dalla Montà (2013)
Occurrence of two different development patterns in Lobesia botrana (Lepidoptera: Tortricidae) larvae during the second generation
Agricultural and Forest Entomology 15 (4), 398-406
Abstract: In north-eastern Italy, the second-generation larvae of Lobesia botrana (Den. and Schiff.) (Lepidoptera: Tortricidae) can develop with two different time patterns. In particular, in 'warmer' areas, the developmental time is shorter than in 'cooler' areas and it is associated with an earlier and more economically important third generation.
Because the differences in temperature are not sufficient to explain the two patterns, research was carried out aiming to investigate whether the differences in larval development time are the result of a different number of instars and whether the photoperiod is a factor.
In the field, second-generation larvae develop through five instars in a 'warmer' area and through six instars in a 'cooler' area. Laboratory and field data showed that decreasing photoperiod, which induces diapause, is also an important cue for inducing larvae to develop six instars.
In the light of climate warming and subsequent changes in L. botrana phenology over the last 30 years, the two different development patterns are interpreted as a means to ensure the best fit of the moth to environmental conditions. In 'cooler' areas, third-generation larvae might not complete development before frost or harvest, and hence second-generation larvae develop through six instars before producing overwintering pupae.
(The abstract is excluded from the Creative Commons licence and has been copied with permission by the publisher.)
Link to article at publishers website
Database assignments for author(s): Francesco Pavan, Pietro Zandigiacomo

Research topic(s) for pests/diseases/weeds:
general biology - morphology - evolution
population dynamics/ epidemiology

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Pest and/or beneficial records:

Beneficial	Pest/Disease/Weed	Crop/Product	Country	Quarant.
	Lobesia botrana		Italy