Ethological and morphological notes on Tomosvaryella frontata (Diptera: Pipunculidae), parasitoid of the tamarix leafhopper Opsius stactogalus

Ethological and morphological observations carried out on a pipunculid fly Tomosvaryella frontata, living on the Tamarix leafhopper, Opsius stactogalus, are presented. The pre-mating phase is characterized by a long period in which the couple fly for a long time close to the leaves; mating is repeated and characterized in both sexes by intense abdominal vibrations of short duration. Concerning the larval morphology, the young larva is maggot-like with well developed spinules on each thoracic and abdominal segment and a terminal vesicle. The head is undifferentiated with a simple mouth opening with no labial structures and an indistinct cephalopharyngeal skeleton. No spiracular openings are present. The full-grown larva shows a typical cuticle with characteristic outgrowths. The head is markedly bilobate with an antennomaxillary complex at its apex. Maxillary sensory structure shows different sensilla at the tip. The external respiratory system has a pair of anterior spiracles and a pair of posterior spiracles arranged on a sclerotized plate. Morphological features present in both instars are presented and related to their behaviour. Finally, modifications in parasitized leafhoppers are discussed.