Descriptions of immature stages of Trupanea nigricornis and T. bisetosa (Diptera: Tephritidae) from southern California

Abstract

The immature stages of the sympatric, cryptic species Trupanea nigricornis (Coquillett), a flower head-infesting fruit fly that attacks a wide range of hosts in the Asteraceae in southern California, and T. bisetosa (Coquillett), an oligophagous congener that attacks only a few hosts in the tribe Heliantheae, are described and illustrated. Detailed examination with the aid of scanning electron microscopy of the eggs, all 3 instars, and puparia of this taxonomically closely allied generalist and specialist revealed many similarities and very few differences, for instance, most puparia of T. nigricornis were shorter and narrower than those of T. bisetosa. Therefore, major differences in the host-plant specificities of these cryptic, possibly sibling, species were not reflected by substantial morphological differences among their immature stages.