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