Revista Chilena de Historia Natural 79 (1): 29-40, 2006
RESEARCH ARTICLE
Diversity, distribution and floral specificity of tangle-veined flies (Diptera: Nemestrinidae) in
north west Patagonia, Argentina
Tangle-veined flies (Nemestrinidae) constitute a primitive and rather widespread family
among Diptera. The genus Trichophthalma occurs in Australia and South America and is the only one in the family with a
typically Gondwanian, disjoint distribution. The ecology and distribution of most southern South American species of this genus
remains virtually unknown. We studied the diversity, distribution and flower specificity of flower-visiting species of the genus
Trichophthalma in the temperate forests of southern South America in ten sites along an east-west rainfall gradient (37-
40° S) on the eastern slope of the Andes. We recorded nine species of Trichophthalma, which showed an overlapped
distribution along the gradient and different degrees of floral specificity. Three species are reported for Argentina for the first time and
three are first recorded as flower visitors to the local flora. Our results show that while in southern Africa tangle-veined flies are
engaged in highly specialized pollination interactions with long-tubed species, the Trichophthalma spp. Of Patagonia share
their flowers with a diverse and rather unspecialized visitor fauna among which several species of flies, bees and birds are
present.
Key words:
Diptera, Nemestrinidae,
Trichophthalma, pollination Patagonia
