Kretschmarr Cave Mold Beetle - Threats

Threats

The Kretschmarr Cave mold beetle was first listed on the endangered species list on September 16, 1988. Threats to the beetle include loss of habitat due to urban development, invasive species, and mining. Urban development is the number one threat to the beetle and affects their karst environment in many different ways. For instance, urban development may lead to the filling in or collapse of caves, alteration of drainage patterns, alteration of surface plant and animal communities, as well as contamination and human visitation. Many caves are filled in or collapsed during road and building construction. A solid foundation is required for construction to take place so if there is a cave in the way it will be collapsed and filled for a sturdy foundation. Road development destroys a majority of the karst habitats where the beetles live. It is estimated that 10% of all caves in Travis County are destroyed every ten years. Some ranchers even lead to the problem. Many of them fill the entrances to the caves so their livestock do not roam into the caves. This blocks the air movement in the cave changing the conditions in the cave. If conditions are not just right the beetle will die. Large paved areas and drainage systems that are put in during urban development alter the natural drainage patterns causing major problems to karst environments. This environment depends on air filled gaps and infiltration from water above, diverting water away from a cave can dry it up killing all the species inside. If water is diverted into a cave it can flood and alter living conditions. Altering surface plant and animal communities affects karst environments as well. When these communities are removed for development many of the nutrients that originally entered the cave are now lost. Without nutrients the beetle and other karst invertebrates can not survive. If a substantial amount of vegetation is removed, infiltration will increase changing their delicate habitat. The caves also face the threat of contamination when developing close to their habitat. Karst is very susceptible to groundwater contamination so when sewer and drainage systems are put in contaminated water can enter the caves. Many of the caves in Travis County are used for disposal of refuse and have probable killed most organisms within the cave. Farming as well leads to the contamination of habitat. Fertilizers, pesticides, and other agricultural waste can infiltrate through the ground contaminating the groundwater that enters the cave. The final way urban development has increased the loss of habitat is by increased human visitation. When humans build close to a species habitat it likely that visitation to the cave will increase. Some species are scared off by this new visitation. If one species leaves it often affects the whole chain of that ecosystem. Some caves are vandalized so much so that it changes the environment in which the beetle lives.

The introduction of invasive species, mainly the red fire ant, has been known to disrupt the beetle’s environment. Shallow caves in which the beetle live are relatively easy to enter and make them vulnerable to invasion of fire ants and other exotic species. . Fire ant colonies occur in two different forms, single queen colonies and multiple queen colonies. It is the multiple queen colonies that pose a threat because they occur in very dense concentrations of about 750-5000 mounds per acre. They can enter through the cave entrance or crawl through small holes or cracks and attack the karst species where humans cannot observe. Slow moving adults, nymphs, and eggs are most vulnerable to fire ant predation. More than 50% of the caves observed had fire ants present. This is a large sign that the fire ant has taken over or will eventually take over the habitat. Even if the fire ant does not prey on the beetle it is likely to change the links that are critical in the food chain.

Mining and quarrying pose a threat to all species, cave dwellers and land dwellers that live in or around the karst habitat. Karst offers a good amount of limestone and there are several limestone quarries in the area. They blast the limestone first then haul it off with heavy machinery. The roads that are built to mine the limestone can break up habitat for miles. All of this destroys caves and surrounding land where the Kretschmarr Cave mold beetle and other karst fauna live.