After nearly a century of dominance, the red imported fire ant (Solenopsis invicta) has met its match in the southeast United States. In 2002, rasberry crazy ants (Nylanderia fulva) invaded Houston, Texas, and has since, completely displaced S. invicta, reduced native ant and non-ant arthropod abundance, and has shown the potential to cause even greater environmental and economic harm than its invasive predecessor. The negative effects of N. fulva and potential for further damage to native ecosystems highlight the necessity of understanding the biotic and abiotic factors responsible for their invasion success. To determine the abiotic and biotic factors that contribute to the abundance of N. fulva, 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 was utilized at the University of Houston Coastal Center in a tallgrass prairie near Houston, Texas. Arthropods were collected by sweep netting in May 2016, and were sorted and identified to species. In addition, plant biomass, plant composition, and soil characteristics were measured to determine which factors are most important for the invasion success of N. fulva.
Initial results show that biotic and abiotic factors both contribute to N. fulva abundance. N. fulva was abundant in all treatments; however, fertilized plots had a higher abundance of N. fulva when compared to the control. Overall abundance of other arthropods (particularly, Hemiptera and Hymenoptera) decreased as N. fulva abundance increased, indicating that N. fulva had a negative effect on native arthropod abundance and diversity. This experiment provided evidence that both abiotic and biotic factors contribute to the invasion success of N. fulva in a coastal tallgrass prairie.