Characterisation of Predator-Directed Displays in Tephritid Flies



Dinesh Rao, INBIOTECA, Av. de las Culturas Veracruzanas, No.101, Col. E. Zapata C.P. 91090, Xalapa, Veracruz, México.



Flies of the family Tephritidae are known to perform a display in front of their salticid spider predators. This display involves extending the wings while the fly moves from side to side. The wings of many of fly species are banded, and in some species, these bands are thought to deter their predators by mimicking the leg patterns of salticids. However, as this display is also seen in non-mimicking flies, there is some uncertainty over the functional significance of these displays. In this study, we explored the efficacy of displays by the lightly banded but non-mimicking Mexican fruit fly (Anastrepha ludens) in deterring attacks by the salticids Paraphidippus aurantius and Phidippus bidentatus. We tested the effect of band visibility and the fly's physiological condition on the production of these displays and the probability of attack by salticids. We filmed the interactions of flies and spiders and analysed fly displays in the presence of the salticid. We show that the fly's display deters salticids and promotes the fly's chances of survival and that the presence or absence of bands does not alter the possibility of attack. Flies fed on different quality diets showed similar rates of display. Our results suggest that tephritid flies deter attacks because of their display and not their appearance.