Tritrophic interactions between fruit flies (Diptera, Tephritidae), their hosts and parasitoids in the main fruit production regions of Uruguay

Doctoral thesis abstract

Abstract

Fruit flies, Ceratitis capitata (Wiedemann) and Anastrepha fraterculus (Wiedemann) (Diptera: Tephritidae) cause severe damage to fruit production in Uruguay. Understanding the tritrophic interactions between Tephritidae, their hosts and their natural enemies, as well as determining the volatile compounds that mediate these interactions, would provide knowledge to manage this group. The objectives of this thesis were to prospect the species of fruit flies present in the country, their parasitoids, and the establishment of hosts. Also, to determine the population fluctuation of C. capitata and A. fraterculus. Finally, to study the trophic interactions of fruit flies and its native hosts, to identify the volatiles produced by native host and their role as host location chemical cues. To do this, McPhail traps and fruit collections carried out in native and productive ecosystems in northern and southern Uruguay. The volatile compounds that mediate the interactions in a native system A. fraterculus and two hosts, Acca sellowiana and Psidium cattleianum, were also studied. As part of the results, new fruit fly species were registered: Anastrepha dissimilis, Anastrepha nigra, Anastrepha australis, Anastrepha littoralis, Neosilba pradoi and Diasiopos frieseni and the parasitoids Opius bellus, Utetes anastrephae, Doryctobracon areolatus and Doryctobracon brasiliensis (Hymenoptera: Braconidae). Ceratitis performs best in disturbed agroecosystems while A. fraterculus adapts better to ecosystems with little anthropogenic intervention. The immature and mature fruits of A. sellowiana and P. cattleianum showed differences in their volatile profiles, and they were attractive to mated females of A. fraterculus. This suggests that volatile organic compounds may be a reliable host location signal for the insect, with potential use as attractant for the management of this species.