John T Gruber, Ryan W Reihart



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Coastal tallgrass prairies are an endangered ecosystem, which is currently threatened by the invasion of rasberry crazy ants (Nylanderia fulva), especially near Houston, Texas. Since the invasion of N. fulva in 2002, this species has been able to reach extremely high densities, reduce native arthropod abundance, and has completely displaced the red imported fire (Solenopsis invicta), its invasive predecessor. Despite knowing the negative effects that N. fulva has on ecosystems, the biotic and abiotic factors that are responsible for its invasion success remain unknown. To determine the abiotic and biotic factors that contribute to N. fulva’s abundance, we utilized a fully factorial blocked experimental design, which manipulates macro- and micronutrients (N&P, Ca, K, and Na; all possible treatments = 16 combinations x 8 replicates = 128 plots) in large 32 m x 32 m plots at the University of Houston Coastal Center in a coastal tallgrass prairie near Houston, Texas. Arthropods were collected by sweep netting in May 2016, along with measurements of plant biomass, plant composition, and soil characteristics to determine which factors are most important for the invasion success of N. fulva. Arthropods were sorted and identified to species. Initial results show that biotic and abiotic factors both contribute to N. fulva abundance. N. fulva was the most abundance arthropod species in all treatments. Our preliminary data shows evidence that N. fulva is limited by calcium, and co-limited by macronutrients (N and P) and sodium. In addition, N. fulva had an overall negative effect on arthropod abundance, particularly Hemipterans (true bugs) and other Hymenopterans (ants, bees, and wasps). These results indicate that biotic and abiotic factors both contribute to the invasion success of N. fulva, and without intervention, N. fulva could devastate what is left of coastal tallgrass prairies.

Publication Date


Project Designation

Graduate Research - Graduate

Primary Advisor

Chelse Prather, Misty K. Thomas-Trout

Primary Advisor's Department



Stander Symposium project

Coastal craziness: factors that regulate an invasive ant in a coastal tallgrass prairie