抄録
The tendency to insert eggs into substrate was compared among 6 species of the Drosophila melanogaster species sub-group by measuring the proportion of eggs deposited on filter paper placed on medium. Flies having a strong tendency to insert eggs avoid paper because it is impossible for them to insert eggs into the paper. D. melanogaster has a large genetic variation in this behavior. But two of its sibling species, D. simulans and D. mauritiana, showed no intraspecific genetic difference in the choice of oviposition sites; they laid almost all the eggs on the medium. Three other siblings, D. yakuba, D. teissieri, and D. erecta, also showed a strong tendency to avoid paper. The force to insert eggs into the medium was measured by changing the agar concentration of the medium. Among 6 species, the order in strength of the pressure to insert eggs is D. teissieri<D. melanogaster<D. yakuba<D. simulans<D. mauritiana <D. erecta. Evolutionary aspects of this behavior are discussed.
