Investigation of the Relationship between Ceuthophilus secretus and Solenopsis invicta with the Application of the Hot Water Treatment
To protect endangered karst invertebrates in Texas cave ecosystems, the relationship between Ceuthophilus secretus (secret cave cricket) and Solenopsis invicta (red imported fire ant) as related to the use of a hot water treatment on fire ant mounds was analyzed. Cave crickets are an important source of nutrient input for caves, making them vital in supporting cave biodiversity. Since the 1980's, the red imported fire ant has spread over the Southern region of the United States, constructing mounds near caves and potentially having a negative effect on cave crickets. Fire ants are aggressive omnivores and scavengers, meaning predation of cave crickets or competition for food resources could occur between the two species. Both Government Canyon and Camp Bullis in Bexar County use treatments of boiling water mixed with soap on fire ant mounds within 50 meters of cave entrances known to contain cave crickets. The number of treated fire ant mounds was compared to the number of observed fire ant mounds at control caves at Camp Bullis and it was found that the hot water treatment reduced the number of fire ant mounds by over 60%. The bivariate analyses displayed significant relationships between cave cricket abundance and external temperature and the average number of fire ant mounds prior treatment. The number of fire ant mounds was related to external relative humidity and average number of fire ant mounds prior to treatment. By monitoring and treating fire ant mounds near caves, the biodiversity of the cave might be maintained and protected.