Invasive Species Compendium

Detailed coverage of invasive species threatening livelihoods and the environment worldwide

Abstract

Larval feeding and development of Leucopis ninae Tanasijtshuk and two populations of Leucopis gaimarii Tanasijtshuk (Diptera: Chamaemyiidae) on Russian wheat aphid, Diuraphis noxia (Mordvilko) (Homoptera: Aphididae), in Washington.

Abstract

Three populations of Leucopis including L. ninae and two populations of L. gaimarii were studied to determine their relative larval development times and feeding rates at different temperatures. Using three experimental temperatures (20.0, 23.3 and 26.6°C), it was determined that the development times of all 3 populations significantly decreased with increasing temperature. Additionally, the number of Diuraphis noxia consumed per day significantly increased from the lowest to the highest experimental temperatures for each population. There were few differences among the 3 populations for the aspects studied, although one population of L. gaimarii had a significantly (P>0.005) longer 3rd stadium (and total larval duration) at the lowest experimental temperature than either L. ninae or the other population of L. gaimarii. This coincided with a higher mean number of aphids consumed for this population at this temperature. Most importantly, it was found that these Leucopis species are voracious predators on aphids, with each individual killing approximately 100 aphids throughout larval life. Also, the data suggest that the species native to the Pacific Northwest, L. gaimarii, is as effective a predator on D. noxia as the introduced species, L. ninae.