Zoological Studies

Vol. 46 No. 5, 2007

Asymmetrical Reproductive Isolation between Drosophila albomicans and D. nasuta

Hwei-yu Chang1,2,* and Yu-Ta Tai1

1Department of Entomology, National Taiwan University, Taipei 106, Taiwan
2Research Center for Biodiversity, Academia Sinica, Nankang, Taipei 115, Taiwan

Hwei-yu Chang and Yu-Ta Tai (2007) The species status of the taxa, Drosophila albomicans and D. nasuta, has been an issue because no obvious reproductive isolation has been reported. For both D. albomicans and D. nasuta females, although the mating speeds differed in the single-choice mating tests, without time limitation the successful mating percentage of intraspecific crosses was the same as that of interspecific ones. However, by comparing“multiple-choice”,“dual-choice”, and“single-choice”experiments, there is evidence for female mating preference and male-male interactions in D. albomicans. These 2 components of sexual selection were not observed in D. nasuta. The implication of this asymmetrical premating sexual behavior in D. albomicans on the speciation history of this species is discussed.

Key words: Behavior, Evolution, Female choice, Lek, Male interference.

*Correspondence: E-mail:hwei@ntu.edu.tw