Life History, Seasonal Phenology, and Parasitoids of the Hawaiian Endemic Moth Udea Stellata (Lepidoptera: Crambidae)

Abstract

Abstract This study presents basic information on the life cycle, seasonal phenology, and parasitism of the endemic Hawaiian moth Udea stellata (Butler) (Lepidoptera: Crambidae), a species for which little biological information is available, even though it was described more than a century ago. By observation of ecdysis and measurements of corresponding head capsule widths under laboratory conditions, we determined that U. stellata undergoes six larval stages. All larval stages had distinct ranges in head capsule width. Duration of each larval stage as well as the egg and pupal stage are reported. Endemic host plants of U. stellata, Pipturus spp. (Urticacea), were sampled at eight field sites between July 2004 and July 2006. Temporal differences in density of larvae were most pronounced in medium- and high-elevation sites, possibly an effect of more marked seasonal temperature changes. The parasitoid assemblage associated with U. stellata consisted of seven species: three adventive species, two purposely introduced species, and two of unknown origin. Adventive parasitoids rather than purposely introduced parasitoids were responsible for the greater part of the apparent mortality observed.