The genus Gaura (Onagraceae) comprises 21 species native to North America, ranging from central and southwestern United States to Mexico and Guatemala, centering on Texas. Five species are self-pollinating, and of the 16 outcrossing species, 13 are reported to be pollinated by small moths, one by hawkmoths, and two by bees, butterflies and flies. As part of an analysis of the evolution of pollinating mechanisms in the genus, we studied G. villosa, a species characteristic of sandy soils, at the Monahans Sandhills and nearby sites in western Texas, with repeated visits throughout the daily and seasonal flowering cycle. The pattern that emerged was unexpectedly complex: a total of 505 individuals of at least 34 species of insects were collected while visiting the flowers, including beetles, flies, bees, butterflies, moths, and antlions. Five species were overwhelmingly important as floral visitors and pollen vectors: two species of halictid bees (Sphecodogastra), two noctuid moths (species of Bulia and Melipotis), and the antlion Scotoleon minusculus. At least four other species of antlions visit the flowers and carry pollen; all visits by antlions occurred between midnight and 5:00am, which may explain why this phenomenon has not been reported before. This is the first documentation of pollination by antlions, and may be the first for any member of the insect order Neuroptera.

Key words: antlions, Gaura villosa, Neuroptera, Onagraceae, pollination