Egg parasitoids of tabanids in Manitoba : prevalence, taxonomy, behaviour, and use of polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) to establish host-parasite interrelationships
Tabanid egg masses were collected from different locations in Manitoba (Canada) during the summers of 1996-2000. Two scelionid parasitoids (Telenomus species A and B) were reared from horse fly egg masses (Hybomitra spp.) and another scelionid parasitoid (Telenomus species C) along with one trichogrammatid parasitoid (Trichogramma semblidis (Aurivillius)) were reared from deer fly egg masses (Chrysops spp.). The taxonomy and host-associations of ten Telenomus species recorded from eggs of Tabanidae in different geographical regions of the world were reviewed and type specimens of these species were compared with specimens reared in Manitoba. Based on characters on the metasoma, mating behaviour and host partitioning, three scelionid parasitoids reared from tabanid eggs in Manitoba were undescribed. These three species were described and an identification key for New World species (including new species from Manitoba, and one Palaearctic species) was provided.... There was a small degree of intraspecific variation among fragment patterns observed when multiple individuals of a species were examined. The rDNA IGS therefore provided a target sequence with sufficient variation to identify individual tabanids to the species level. Then using molecular markers, 56 egg masses of horse flies and deer flies collected in Manitoba were matched with their associated adults. Descriptions of egg masses of five species (H. n. nuda, Hybomitra lasiophthalma (Macquart), Chrysops mitis Osten Sacken, C. aestuans, and Chrysops excitans Walker) of tabanids along with colour pictures are provided.