Cues used during the host recognition by Phymastichus coffea, a parasitoid of the coffe berry borer

The wasp Phymastichus coffea LaSalle (Hymenoptera: Eulophidae) is a parasitoid of the adults of the coffee berry borer (CBB), Hypothenemus hampei (Ferrari) (Coleoptera: Curculionidae), considered the most important pest of this crop. A previous study has shown that A coffea uses long-range chemical cues during the host location process. The objective of this study was to investigate the role of physical and chemical cues at short range during the host recognition by P. coffea. The assays were performed with glass vials used as experimental arenas under laboratory controlled conditions. The results showed that the movement of the host did not influence the recognition process. CBB females were better accepted than males by P. coffea, mostly because they are bigger than males. The use of spherical plastic models, instead of borers, allows confirming that size is an important cue for host recognition by P. coffea. Color did not affect the time spent by parasitoids in contacting the host, though dark colors were handled longer by P. coffea. Our results seem to suggest that cuticular compounds were not involved in host recognition by P. coffea.