Research Information System
Southwestern Entomologist, vol.30, no.1, pp.9-15, 2005 (SCI-Expanded)
Surveys were conducted during 2001-2002 of nymphal Lygus spp. to determine incidence of the braconid parasitoid Leiophron uniformis (Gahan) in Colorado. The parasitoid was collected in all eastern Colorado sites, but not in sites in the San Luis Valley or west of the Continental Divide. Average combined parasitism for all sites was 5.54 and 7.62% in 2001 and 2002, respectively. Parasites were recovered from Lygus nymphs collected from May through October, consistent with a multivoltine life cycle. Highest percentage parasitism occurred with Lygus nymphs collected on alfalfa and canola. Parasitized nymphs were also collected from lambsquarters, flixweed and kochia, but not redroot pigweed. In 2002 the Lygus sp. found in highest percentage (58.4%) was L. elisus Van Duzee, which was particularly abundant during early season collections on flixweed and alfalfa/flixweed mixtures. L. hesperus Knight was second most abundant (29.3%) and was common on weed hosts lambsquarters and kochia. L. lineolaris (Palisot de Beauvois) comprised 12.3% of the 2002 collection and was most abundant on alfalfa and canola.