Leaf cutting-ants: Control methods and sustainability

• Autor(a) principal: Ortiz, Gabriela [UNESP]
• Data de Publicação: 2012
• Outros Autores: Mathias, Maria Izabel Camargo [UNESP]
• Tipo de documento: Capítulo de livro
• Idioma: eng
• Título da fonte: Repositório Institucional da UNESP
• Texto Completo: http://hdl.handle.net/11449/220092

The fungus-growing ants belong to the genus Atta and Acromyrmex and individuals are causing serious damage to various types of plantations due to the habit of cutting leaves and shoots of economic importance for use in cultivating the garden symbiotic fungus colonies, causing serious damage. The ants attack is harmful at any stage of the cycle, but the damage is greater in the training phase of the plant, when temporarily paralyzes growth. In an attempt to reduce the damage caused by these insects farmers make the control of fire ants through the use of mechanical methods, biological and chemical. The mechanical control is to dig the nest to remove the queen (individual responsible for placing the eggs that give rise to other individuals in the colony), which are larger in size than workers, causing a disruption of the nest, since the queen controls all activities and individuals in the colony. This type of control has been recommended only for newly formed nests, otherwise, the queen will be housed in great depth, making its removal. It should be noted that in practice such control is not a good alternative in commercial plantations due to the large extent of the property. Chemical control can be accomplished by applying powder, liquid insecticide, thermonebulization and granulated bait. The powder is a type of insecticides formulated in solid vehicles, such as talc, and the application is through hand pumps. The death of ants occurs by direct contact with the chemical. However, this type of control has limitations such as the impossibility of penetration of the product in the deepest chambers of nesting adults, and has now been replaced by liquid thermonebulized, through which the product is injected into the nest with the help of hose, and toxic bait, which is considered more efficient due to easy handling, fast action and lower costs. The bait is distributed on the tracks near the colony of ants to be transported into the nest by workers. This method can cause much damage to non-target ants and even other bodies. Finally, it has been used the biological control, which is the introduction of natural enemies in plantations, such as birds, some species of spiders, beetles, mites and even other species of ants, and much research is currently focused on creating natural insecticides that have repellent action or lethal to the ants, such as castor oil, or fungicidal against the garden of fungus that feeds the colony, as is the case of sesame. Studies on the morphology of the reproductive organs of these ants could also be an important tool in the search for new methods of control. Some studies have been conducted on the morphology of the spermathecae of ants, the body that produces all the elements capable of maintaining viable sperm inside, where it was observed that products circulating in the hemolymph, due to the thin wall thickness of the the spermatheca, also could enter the environment within this structure, where are the sperm and thus affect their viability. © 2012 by Nova Science Publishers, Inc. All rights reserved.