An infestation of miltogrammine Sarcophagidae (Diptera: Sarcophagidae) in a population of Hybomitra lasiophthalma (Macquart) (Diptera: Tabanidae)

A second isolation of Macronychia sp. near to M. aurata (Coq.) from adult tabanids in Texas [see RAE/B 66, 2997] was made in April 1977 from examples caught in the flood plain near College Station, but this time the host tabanid was Hybomitra lasiophthalma (Macq.). The apparently high incidence of parasites (22%) in this tabanid population is partly accounted for by the observed frequency of superparasitism; 3 of 4 parasitised Hybomitra females contained 2-5 Macronychia larvae. Macronychia was also found parasitising Tabanus subsimilis subsimilis Bellardi [loc. cit.], and the timing of parasitism of H. lasiophthalma and of T. s. subsimilis suggests that the first tabanid species acts as host to the first generation of Macronychia, and the second species (and perhaps also other species of Tabanus) to the subsequent generations of the parasite.