The decline in water supply for irrigation in the Texas High Plains is encouraging some growers to produce dryland forages. 'WW-B.Dahl' Old World bluestem [OWB, Bothriochloa bladhii (Retz) S.T. Blake] is a drought-tolerant grass in dryland and limited-irrigation conditions. This grass reportedly repels red imported fire ants (RIFA, Solenopsis invicta Buren); however, broader insect communities associated with OWB have not been investigated. We characterized the ground-active arthropod community occurring in OWB, OWB-alfalfa (Medicago sativa L.), alfalfa, and native mixed grass pastures by using pitfall traps over 3 years. Forty-seven families among 10 insect orders and five families of five non-insect arthropod orders were collected. Beside ants (Hymenoptera: Formicidae), the most abundant taxa collected were ground beetles (Coleoptera: Carabidae) and click beetles (Coleoptera: Elateridae), house flies (Diptera: Muscidae), butterflies (Lepidoptera: Pieridae), and field crickets (Orthoptera: Gryllidae), with jumping spiders (Araneae: Salticidae) and sow bugs (Isopoda: Oniscidae) representing the non-insect taxa. Pastures containing OWB had nearly zero (P < 0.001) RIFA and harvester ants (Pogonomyrmex spp.), but no other arthropod family responded to forage treatments. Ant abundances were greatest in the native mix and intermediate in the alfalfa and teff [Eragrostis tef (Zucc.) Trotter] pastures. The relatively low abundances of RIFA and harvester ants in the OWB and OWB-alfalfa mixture compared to the other forage treatments suggest that WW-B.Dahl OWB might act to deter activity of ants, yet further studies are needed to determine the specific mechanisms and insect-deterring traits of these forage systems to support strategies for pasture management.