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Leaf-cutting Ants
Dátum pridania: | 30.11.2002 | Oznámkuj: | 12345 |
Autor referátu: | neuvedeny | ||
Jazyk: | Počet slov: | 3 882 | |
Referát vhodný pre: | Stredná odborná škola | Počet A4: | 11.9 |
Priemerná známka: | 2.98 | Rýchle čítanie: | 19m 50s |
Pomalé čítanie: | 29m 45s |
Bucher in 1982 found that the effects of the nests last for a long time when it is abandoned. Communication
The type(s) of communication leaf-cutting ants use is still in the process of research. What we do know is that workers produce vibrational signals while they are cutting leaves (Roces, Holldobler, Tautz, Kleineidam, Krumme). The vibrations have two purposes. They act as close-range recruitment signals and it also facilitates the cutting of leaf tissue, like a vibrating knife or jigsaw. The plant-borne vibrations produced by the workers are used by other workers in locating the cutting site(s). Roces, Holldobler, Tautz, Kleineidam, and Krumme found that the vibrations mean differently to the ants depending on the social context being used. The leaf-cutting ants also produce rapid vibrations, which are audible to humans, the ant does this by rubbing two abdominal organs –one a sharp scraper which scratches the fine ridges on the other. The vibrations radiate along the ants body all the way to her sickle, serrated mandibles. The mandibles vibrate up and down at 1,000 Hz at the ant uses one mandible to cut the leaf (Beatman 1995). Roces and company also found that the leaf-cutting ants carry several thousand chemo and mechanoreceptors but only 12 sensilla that respond to carbon dioxide. These sensilla act as measuring devices which constantly measure atmospheric carbon dioxide. The ants can scan spatial and temporal carbon dioxide gradient and using this mechanism they can locate the entrances to their nest. It was found that the ant even move their antennae in such a patter which stimulates the carbon dioxide sensillae optimally (Roces, Holldobler, Tautz, Kleineidam, and Krumme). Control
Controlling leaf-cutting ants is a major problem is some countries. The structure of the ants’ nests make it extremely difficult to destroy with pesticides and machines. Individual plants can be protected by using insecticides such as acephate (Orthene), diazinon or chlorpyrifos (Dursban), but these treatments do not affect the colonies. The Eradicator Fire Ant Eradicator System can be used on leaf-cutter ants too. It is designed to injects vaporized resmethrin. Methyl bromide gas (from Great Lakes Chemical Corporation’s Brom-O-Gas) is very effective against the ants. But this is highly toxic to humans, plants, and animals. There is also some concerns about the toxin travelling up ecosystems. Thus you have to have a special permit to use it. Production of the gas will be terminated at the end of the year 2000.