Among checkered beetles (family Cleridae), the genus Trichodes contains among the largest and most strikingly-colored species. The 11 North American species of this predominantly Holarctic genus are primarily western in distribution, although two species (T. nuttalli and T. apivorus) do occur in the eastern U.S. The individual in these photos was one of several I encountered feeding on the flowers of a yellow composite in the Gloss Mountains of northwestern Oklahoma during early July. I take them to represent the species T. bibalteatus based on their close resemblance to the holotype of that species from the LeConte Collection in the Museum of Comparative Zoology at Harvard University. While these photographs are admittedly far from perfect, they were about the best I could manage at the time considering the gusty post-storm winds that I encountered atop the mesa where these beetles were found (along with my continuing difficulty in achieving proper exposure with subjects on bright yellow flowers).
The striking colors of adult Trichodes and their frequent association with flowers for feeding and mating belies a more treacherous aspect of their life history. While adults may serve as important pollinators of native plant species (Mawdsley 2004), they also lay their eggs on flowers. The larvae that hatch from these eggs don’t eat the flower itself, but rather attach themselves to bees and wasps that visit the flower as they gather pollen for provisioning their own nests (Linsley & MacSwain 1943). The larvae hitch a ride back to the hymenopteran’s nest, where they then prey on the developing brood and usurp pollen provisions for themselves.
Photo Details: Canon 50D w/ MP-E 65mm 1-5X macro lens (ISO 100, 1/250 sec, f/16), Canon MT-24EX flash (1/8 ratio) w/ Sto-Fen + GFPuffer diffusers. Typical post-processing (levels, minor cropping, unsharp mask).
Linsley, E. G. & J. W. MacSwain. 1943. Observations on the life history of Trichodes ornatus (Coleoptera, Cleridae), a larval predator in the nests of bees and wasps. Annals of the Entomological Society of America 36:589–601.
Mawdsley, J. R. 2004. Pollen transport by North American Trichodes Herbst (Coleoptera: Cleridae). Proceedings of the Entomological Society of Washington 106(1):199-201.
Copyright © Ted C. MacRae 2010