Supplemental Feeding Increases the Utilization of a Factitious Host for Rearing Bracon thurberiphagae Muesebeck (Hymenoptera: Braconidae) a Parasitoid of Anthonomus grandis Boheman (Coleoptera: Curculionidae)

Bracon thurberiphagae is a parasitoid attacking Anthonomus grandis thurberiae, the thurberia weevil. Although B. thurberiphagae can be reared on the boil weevil, the host is expensive to maintain in the laboratory and varies greatly in quality. Heliothis virescens was tested as an alternate host for rearing B. thurberiphagae because of their more consistent quality and availability, but after three generations the B. thurberiphagae population was severely reduced. After the addition of several amino acids to an adult wasp diet, a 100% improvement in the fecundity of B. thurberiphagae reared on H. virescens was observed and a 1:1 sex ratio was restored. This resulted in the ability to maintain a strong colony on an otherwise unsuitable factitious host. The rearing of B. thurberiphagae on H. virescens did not alter their response to boil weevil cues. These results are important in that they demonstrate that the selection of factitious hosts does not necessarily depend on whether the host is suitable, but that the suitability may be manipulated to some degree.