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The semiarid Texas High Plains has a declining water supply for irrigated crop production because of unsustainable pumping from the Ogallala aquifer. Conversion of land from annual crops to limited‐irrigated perennial forages is an option for profitable land use. ‘WW‐B.Dahl’ old world bluestem [Bothriochloa bladhii (Retz) S.T. Blake, OWB] is a well‐adapted grass known for deterring some soil‐dwelling insects, but effects of OWB on insect pollinators are unknown. The aim of this study was to determine whether adapted forage types (species or mixtures) affected insect pollinator abundance in pastures. Foraging insects were collected using bee bowls and compared among OWB alone, OWB mixed with alfalfa (Medicago sativa L.), alfalfa, and a native grass mix. Twenty‐one families from four orders of insects were recovered over 3 yr. Sweat bee (Hymenoptera: Halictidae) was the most abundant family, with 59% of the total number of insects collected. Honey bees (Hymenoptera: Apidae) constituted an additional 17% of the total number of insects collected, with hover flies (Diptera: Syrphidae) and skippers (Lepidoptera: Hesperiidae) found in lesser abundances. Interactions between forage type and years restricted consistent forage‐type effects. In general, the lowest abundances of foraging insects were commonly found in OWB growing alone, especially of the native, ground‐nesting sweat bee, whereas greater abundances were more commonly found in native grass and alfalfa pastures. Widespread adoption of WW‐B.Dahl OWB may reduce local numbers of foraging insects in the Texas High Plains, which could negatively affect pollinators in managed grasslands.

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Core Ideas Red imported fire ants and harvester ants account for most of the arthropods found. Forage types did not differ in numbers of non‐pest and beneficial insects. Old World bluestem provided an unfavorable habitat for ants but not desirable insects. Deterrence towards deleterious ants promotes resilience of Old World bluestem 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.

Aspergillus flavus refers to a diverse group of saprophytic soil fungi that includes strains producing aflatoxins (toxigenic strains) in the kernels of corn (Zea mays L.) and other crops, causing pre-harvest and post-harvest aflatoxin contamination. Some A. flavus strains are atoxigenic, and the introduction of such strains into the crop environment helps reduce toxigenic aflatoxin contamination. Corn growers in Texas have used the product FourSure™, which contains four atoxigenic strains of A. flavus; however, effects on soil microbial communities associated with these applications are unknown. We compared soil fungal and bacterial communities in corn fields treated with FourSure™ to nearby untreated (control) corn fields in Texas during the summer of 2019. Analysis of soil microbial community structure showed that total fatty acid methyl esters (FAMEs), fungal, and bacterial populations were not significantly different (p = 0.31) between the FourSure™-treated and control fields, yet corn fields located in the northern counties had more (p < 0.05) Gram—bacteria, actinobacteria, and total bacteria than fields in the southernmost county. The Gram—bacteria and actinobacteria were positively correlated (p = 0.04; r = 0.48 and 0.49, respectively) with soil water content. Similar fungal and bacterial abundances between FourSure™-treated and control fields indicated that atoxigenic A. flavus had no negative effects on soil microbial communities.