Delphacodes scolochloa Cronin and Wilson is a newly discovered delphacid planthopper that feeds and oviposits exclusively on the stems of sprangletop (Scolochloa festucacea; Poaceae) in the prairie pothole region of northeastern North Dakota, USA. Delphacodes scolochloa is bivoltine. It is also wing-dimorphic but populations are composed predominantly of flightless brachypters. Macropters incur a substantial cost in terms of reduced longevity and fecundity relative to brachypters. The parasitoid complex attacking D. scolochloa consists of two egg parasitoids, Anagrus nigriventris Girault and A. columbi Perkins (Hymenoptera: Mymaridae), and one undescribed dryinid. The proportion of eggs parasitized averages 21% and is density independent.
Keywords: Anagrus nigriventris, egg parasitoid, planthopper, prairie potholes, Scolochloa festucacea