Biological Pest Control and Touristic and Educational Exploitation of Zompopas(Atta cephalotes)in the Guayabo National Monument.

Biological Pest Control and Touristic and Educational Exploitation of Zompopas(Atta cephalotes)in the Guayabo National Monument.

The Guayabo National Monument, located in Turrialba (Cartago) and included in the Central Volcanic Mountain Range Conversation Area, is the most important archeological site in Costa Rica. It was recently declared World Heritage in Engineering due to the complexity and efficiency of its carriageways, aqueducts and water drainages, which still work. The monument also harbors notable structures of great cultural value such as mounds, ceremonial plazas, box graves, water capturing tanks and petroglyphs. Unfortunately the conservation of this architectural jewel is threatened due to wearing by various biological agents, being the zompopa ants (Atta cephalotes) the best example. For instance, the most significant carriageway which accessed the old city (Caragra carriageway), constructed with 150 000 large stones, meticulously placed is losing its original conformation due to sinking caused by the ants underground colonies. Likewise, various stone mounds, in which many of the “ranchos” of the original Guayabo residents, including the chief or cacique’s house lay upon, are colonized by zompopas. If no measures are taken the ant’s underground tunnels will cause all of these structures to collapse, causing irreparable damage to these pre-Columbian structures, damaging Costa Rica’s national identity in the process.

Combating zompopas is not an easy task. These ants are considered one of the most important agricultural pests in Latin America, generating losses which are in the billions of dollars each year. Each mature colony can have up to 5 million ants, and consume an approximate 250 kg of plant material (dry weight) every year, all this in an area of more than 20 meters. Zompopas have been shown to have a preference for open areas in the forests to build their colonies. Because of this behavior, there is a high density of zompopa colonies in Guayabo. This sector is a cleared island border by the dense rainforest. This raises the importance of developing integrated management strategies for the control of zompopas in order to preserve the Guayabo Monument for future generations.

The most commonplace strategy for the control of ants is the use of granulated insecticides. However, these compounds present a series of disadvantages, such as rejection by the ant, recuperation of the colonies weeks after application of the insecticide, as well as high toxicity which affects the environment, also causing the deaths of other insects and animals. These characteristics render this methodology useless in the management of ants in Guayabo. Instead, the use of biological pest control using microorganisms to control ants has been supported by various scientific studies. Also the fact that the antagonistic microorganisms are highly specific (do not affect other species), have a low cost of production, and their environmental impact is not significant make these strategies highly viable.

Although zompopa colonies are nefarious to activities such as agriculture, they are an important part in maintaining the balance of tropical ecosystems. They are also a great model to explain people the fundamental concepts of symbiosis, microbiology, ecology and evolution. Due to their size, social nature, complex task network, and the intricate agricultural system based on symbiotic interactions with beneficial microorganisms, as well as the ease to keep them in captivity, zompopa colonies are ideal to establish educative and touristic demonstrations.Capitalizing in the public’s fascination with ant biology, it has been proposed to convert the ants in Guayabo into a part of the monument. This is to be achieved by means of interactive exhibitions, educational brochures, a website, and the orienting of local tour guides.This way, the zompopas that are damaging the park can be controlled more ecologically as well as use them to teach visitors about this interesting insect.