SENSE ORGANS ON THE ANTENNA OF A PARASITIC WASP,<i>NASONIA VITRIPENNIS</i>(HYMENOPTERA, PTEROMALIDAE)

Abstract

1. Although the male of Nasonia vitripennis is distinctly smaller than the female, the antennae are approximately the same size in both sexes. 2. Hairs of two kinds, both believed to be tactile, are present on the antennae of both males and females. One type is found only on the twelfth subsegment. 3. Chemoreceptors of three kinds—thick-walled pegs, thin-walled pegs and plate organs—occur on the antennal flagellum of both sexes. 4. Thick-walled pegs are restricted to the eleventh and twelfth subsegments of the antenna. Elsewhere on the body they were found on the terminal segments of the maxillary and labial palps and on the tarsal claws. 5. Thin-walled pegs are present in large numbers on all subsegments from the third to the eleventh. 6. Plate organs occur on all subsegments from the third to the eleventh. A mean number of 43 plate organs was found on the antenna of the male and 81 on the antenna of the female. The entire outer surface of the plate is perforated by a large number of very small openings.