EFFECTS OF PEA APHID (HOMOPTERA, APHIDIDAE) HONEYDEW ON LONGEVITY ANDFECUNDITY OF THE ALFALFA WEEVIL (COLEOPTERA, CURCULIONIDAE) PARASITOID BATHYPLECTES CURCULIONIS (HYMENOPTERA, ICHNEUMONIDAE)

The ability of parasitoids to attack their hosts may be influenced by the availability of adult food sources such as homopteran honeydew. To test this hypothesis for the wasp Bathyplectes curculionis (Thomson), a parasitoid of the alfalfa weevil, Hypera postica (Gyllenhal), we pe rformed laboratory experiments to determine whether availability of pe a aphid, Acyrthosiphon pisum (Harris), honeydew influenced adult longe vity and fecundity of the wasp. Adult wasps caged with alfalfa, Medica go sativa L., and pea aphids fed on the aphid honeydew and lived appro ximate to 50% longer than wasps caged with alfalfa alone. In a related experiment, newly emerged, unmated B. curculionis females were allowe d to feed for 2 d on pea aphid honeydew, sucrose dissolved in water, o r water alone, and were then dissected to determine the number of eggs in a lateral oviduct. Egg production was slightly (11-15%) but signif icantly greater in females with access to pea aphid honeydew or sugar water than in females with access to water only. These results suggest that availability of pea aphid honeydew in alfalfa fields may enhance the realized fecundity of B. curculionis. Hence, the presence of pea aphids in moderate numbers may be beneficial for biological control of the alfalfa weevil.