Novel insight in the life cycle of Emphasis Type=

Authors: Chiara Ferracini Elena Gonella Ester Ferrari Matteo Alessandro Saladini Luca Picciau Federica Tota Marianna Pontini Alberto Alma

Publish Date: 2014/11/11

Volume: 60, Issue: 2, Pages: 169-177

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Abstract

Torymus sinensis Kamijo Hymenoptera Torymidae is a biological control agent of the chestnut gall wasp Dryocosmus kuriphilus Yasumatsu Hymenoptera Cynipidae It is reported in the literature as univoltine but in NW Italy it exhibits a prolonged diapause mainly as late instar larva Diapause is extended for 12 months and adults emerge in April as usual showing a twoyear life cycle Second year emergence individuals are able to mate and the presence of mature eggs was confirmed in females which parasitised fresh chestnut galls showing the same parasitism behaviour as first year emergence individuals Both sexes of second year emergence individuals proved to be smaller than the univoltine ones according to ovipositor sheath length pronotum width and hind tibia length Proving evidence of the extended diapause plays an important role for the establishment of T sinensis especially in the first years after its release Future studies are needed to clarify the factors which trigger off this responseWe wish to thank Johann Laimer who kindly provided the unparasitised chestnut galls used in the behavioural trials We are also grateful to Michalis Bourellas Marida Corradetti Silvia Di Stefano Cecilia Ferrara Federica Fleury and Valentina Tosi for their technical assistance We are grateful to the anonymous reviewers for their constructive comments which helped to substantially improve the manuscript

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