Prosopis farcta (Fabaceae) is a native and common perennial weed plant in Iran. In search of environmental-friendly control methods against P. farcta, we discovered the seed feeder moth Nephopterygia austeritella (Lepidoptera; Pyralidae) in central Iran and studied its bioecology for the first time from 2008 through 2009. Infestation pattern, larval feeding behaviour, developmental period, seasonal occurrence and the adverse impact of the moth on the reproductive organs of P. farcta were investigated. Diagnostic morphological characters of the fifth larval instar of N. austeritella are provided. Two gregarious ectoparasitoids were reared and identified as Apanteles subcamilla and Phanerotoma leucobasis (Hymenoptera: Braconidae). Mortality rates of the larvae were 3.03 and 13.44% in 2008 and 2009, respectively. Larvae destroyed 29.6-38.4% of the pods of their host plants. The potential of N. austeritella as an efficient biological control agent in IPM programs against P. farcta is discussed.
