Morfologia degli stadi larvali di Habronyx heros Wesmael (Ichneumonidae - Anomaloninae) con note di biologia

Abstract

THE MORPHOLOGY OF LARVAL INSTARS IN HABRONYX HEROS WESMAEL (ICHNEUMONIDAE- ANOMALONINAE) WITH NOTES ON THE BIOLOGY OF THE SPECIES

The author describes the larval features of Habronyx heros Wesmael (Hymenoptera, Ichneumonidae, Anomaloninae). The five larval instars were on, the first of which was caudate and the others worm-like. The morphologicals details of the head were studied: the first instar had strongly schlerotized mandibles and well shaped maxilae and an inferior labrum with sensilla; the second instar was ligthly schlerotized, while the third, fourth and fifth instars showed a progressive thickening of the peristoma, the dorsal half of the head and the inferior labrum. The key for last instar larvae (from Gauld, 1976) was modified according to the hypostomal spur variability ecountered.

The life cycle and the competition among larvae into the host was observed and outlined.

Vengono descritti, con particolare attenzione alle sclerificazioni del capo, i cinque stadi larvali di Habronym heros Wesmael (Ichneumonidae-Anomaloninae). La larva di prima età risulta essere caudata.

Si riferisce la variabilità, nella larva matura, delle mandibole dello sperone ipostomale; tale fenomeno sembra dovuto a fattori trofici.

Vengono fornite alcune notizie sul ciclo biologico e sulla competizione che avviene all'interno della crisalide dell'ospite, la Pachypasa otus Drury (Lepidoptera: Lasiocampidae).