Individuazione di un feromone sessuale marcante traccia nell’imenottero parassitoide Metaphycus luteolus

Stefano Colazza, Ezio Peri, Daniela Lo Giudice

Research output: Contribution to conferenceOther


[automatically translated] Metaphycus luteolus Timberlake (Hymenoptera: encyrtidae) is a gregarious parasitoid facolativo of Coccidia (Homoptera: Coccidae). In the present study, we investigated the existence in this kind of a pheromone that could guide the encounter between the sexes in emergency sites. In other Calcidoidei Hymenoptera, parasitoids of guests who live in dense aggregations like colonies of aphids or scale insects, the encounter between the sexes in the emergency sites is mediated by pheromones short. This study highlights the existence of a trace pheromone M. luteolus. Bioassays were performed with the aid of an open arena, constituted by a glass plate, on which have been virtually defined eight lines radiating from a central point of release. in vivo and in vitro tests they have been performed. In each test, four of the eight lines, choices in alternating position, were treated and the remaining four were left as a control. The male response was biosaggiata, in in vivo tests, in respect of the traces left by the females of the parasitoid, confined and left to walk along the four test lines; in in vitro tests, in respect of cuticular compounds of females, sequentially extracted in hexane and acetone, and applied always along four lines. The males of response was assessed by means of a video-images acquisition system associated with a behavioral analysis program. Both in in vivo testing in in vitro tests, the males responded with a directed movement along the pheromonal traces. The fact that both extracts in polar solvent and in non-polar solvent have induced a research activity suggests that the pheromone is a blend of different polarity compounds. The results show, therefore, that females of M. luteolus leave the "fingerprints" chemical on the substrate where they walk, in respect of which the males responded with a directional movement along the track and an increase in search time.
Original languageItalian
Number of pages1
Publication statusPublished - 2009

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