RELATIONSHIP BETWEEN LARVAL FEEDING-BEHAVIOR AND VIABILITY IN DROSOPHILA-MELANOGASTER AND D-SIMULANS

Larval feeding behavior of isofemale lines of the sibling species Drosophila melanogaster and D. simulans was investigated. This behavior was measured as the number of cephalopharyngeal retractions of individual larvae per 30 sec period (CPR score) in different generations (G0, G1, and G14). In addition, egg-to-adult viability was estimated in each isofemale line. The results were as follows: (1) In either species, there was variation of CPR score among individuals and among isofemale lines. Although no differences of CPR score were found among experimental groups (generations) and between species, there was a significant difference among isofemale lines. (2) The behavioral trait was stable through generations in each isofemale line. (3) This behavior was correlated with egg-to-adult viability, showing that it is important for the development of the fly. © 1979 Plenum Publishing Corporation.