An Analysis of the Grooming Behavior of Wild and Mutant Strains of Bracon Hebet or (Braconidae : Hymenoptera)

Abstract

Grooming behavior in the wild type parasitic wasp Bracon hebetor and ten mutant strains was observed and the grooming movements recorded by a keyboard which activated clocks and an event recorder. The fifteen distinct fixed action patterns used by B. hebetor for grooming were described. These FAPs did not vary qualitatively in any mutant strain examined, nor did the presence or absence of the groomed structure affect the qualitative performance of the FAP. The quantitative analysis showed that grooming behavior in this species appears to be temporally organized in that wasps consistently spent more time grooming head structures and wings than other body parts. In addition, the amount of time spent in a bout of a particular movement was relatively consistent. The sequence of grooming movements was also non-random. Movements were generally clustered into anterior and posterior grooming, but there was also evidence of pair-wise linkage. Multivariate statistical analyses of the grooming frequencies per five minute observation period showed striking sexually dimorphic grooming behavior. Females of all strains spent more time grooming head structures, while males spent more time on wing grooming. Mutant strains differed in times spent on each grooming movement; wasps with structural mutations showing the most deviant grooming frequencies, and eye and body color mutants grooming more like wild type. The deviant grooming frequencies of the structural mutants was in the direction of the altered body part. It was concluded that grooming behavior in B. hebetor was under strong central control, but that altered sensory information could lead to alterations in grooming movement frequencies. The adaptive significance of this behavioral organization was discussed.