GENETIC AND MORPHOLOGICAL VARIATION AMONG BIOTYPES OF TEPHRITIS-BARDANAE

Larvae of the tephritid species Tephritis bardanae develop in flower heads of some Arctium species (Cardueae). Fly populations attacking A. tomentosum plants, which have woolly flower heads, are observed to lay their eggs into the plant stem. This contrasts with the usual egg-laying behaviour within the genus Tephritis, where eggs are normally deposited into flower heads. Allozyme and morphological differences between these biotypes are small, but quite consistent. We compare the genetic distance between these biotypes with other allozyme studies of tephritids, and conclude that the evolution of biotypes is not necessarily matched by genetic differentiation detectable at the allozyme level.