Contribution
Das Treffpunkt-Prinzip als Kommunikationsstrategie und Isolationsmechanismus bei Bohrfliegen (Diptera: Trypetidae)
[The Rendezvous-Behaviour, a Communication Strategy and an Isolation Mechanism in Trypetids (Diptera : Trypetidae)]
Zwölfer, Helmut
Entomologica Germanica Band 1 Heft 1 (1974), p. 11 - 20
29 références bibliographiques
publié: Nov 29, 1974
DOI: 10.1127/entom.germ/1/1974/11
ArtNo. ESP346000101001, Prix: 29.00 €
Abstract
A review of the literature and personal observations on 31 trypetid species associated with Cynareae host-plants indicate that today 18 genera and more than 45 species of trypetids are known to exhibit a characteristic «rendezvous-behaviour»: The males utilize the larval hostplants or parts of them as species-specific waiting-places and as territories for courtship and mating. A statistically highly significant association (96, 7% of the personal observations) was found to exist between the rendezvous-places and the oviposition sites. Experiments with Urophora affinis (Frauenfeld 1856) demonstrated that males recognize the specific host-plant and its proper developmental phase also in the absence of females. Moreover, it was shown that token signals of the host elecit territorial activities among the males. - The rendezvous-behaviour facilitates the synchronization and the spatial encounters between the sexes. In combination with genus-specific signal codes (colour patterns of the wings, signal movements) it serves as an effective isolation mechanism which allows the co-existence of up to 5 different trypetid genera on the same Compositae host. If the sexes do not meet on their specific rendezvous-places, they are not able to recognize conspecific partners. This was shown by interspecific (intrageneric) mating experiments with 8 Urophora- and 4 Chaetorellia-Species which produced 23 different combinations of interspecies-mating. - Further implications of the rendezvous behaviour are a possible stabilizing influence of the territory behaviour and a reduction of the gene flow between populations.