Mechanism of host recognition in Neodohrniphora elongata (Brown) (Diptera: Phoridae)

Insects can use different cues derived from their host or habitat to localize and identify an appropriate host. We conducted this study to investigate the mechanisms used by Neodohrniphora elongata (Brown) to localize and recognize the host Atta sexdens rubropilosa Forel. Females of the parasitoid N. elongata were collected in the field and tested individually in an observation box. The effect of chemical and visual stimuli, associated with A. sexdens rubropilosa, on the location and acceptance behaviour of N. elongata was verified. The chemical stimuli of the ant workers alone triggered no behavioural response in the phorid. Visual stimuli of the ant were sufficient to trigger behavioural acts related to host localization and recognition in the phorids. The trail pheromone of A. sexdens rubropilosa associated with host visualization increased the total time of inspection of a potential host. Visual cues in motion increased the inspection period, compared to static visual cues. Moving basic morphological configurations, regardless of the degree of complexity, triggered similar inspection behaviour as that observed towards live hosts in N. elongata. The phorids, however, did not identify these incomplete morphological models as hosts when static.