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Piatok, 22. novembra 2024
Leaf-cutting Ants
Dátum pridania: 30.11.2002 Oznámkuj: 12345
Autor referátu: neuvedeny
 
Jazyk: Angličtina 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
 

This is when the ants panic because of some enemy and all sizes of ants use matter to close the nest entrances. Avoiding can lead to their not being a battle. This is when ants avoid each other and one or both nests leave the feeding site. The armadillos are the main vertebrate predator of the leaf-cutter ants (Whitehouse & Jaffe 1996). The armadillos dig up the nests to get at the eggs and the many ants tending the nest. As soon as there is a mechanical disturbance of the nest the percentage activity of soldier ants outside of the nests is increased approximately 49%. The number of small ants decreased by an average of 47% on top of the nests (Whitehouse & Jaffe 1996). Thus soldier ants with their large mandibles are a better deterrent against large enemies then small ants. Leaf-cutter ants must also defend against other ants and even against ants of its own species. Ant battles are rare but when they occur they are spectacular. Battles occur when at least 50 ants are fighting. Fighting is done by one ant biting the leg or body part of another ant with its mandibles. Fighting usually occurs in balls of ants with a ball having about 14 ants. Ants start dying usually if the fighting lasts more than one hour. Usually when ants from other nests meet there is a short skirmish and then avoidance. The ant battle operates on the square law which predicts that is all individuals are equally vulnerable to attack then the side with the most attackers will win. Thus many smaller ants are more beneficial then a few large soldier ants. Small ants fight but they also lay down scent or territorial markers. It is found that the better a nests territory is marked, the more likely the nest will win the battle. Thus the more small ants a nest has, the more territory will be marked and more opposition ants will be killed. Also it appears that the large soldier ants are primarily to protect the nest while the small ants and workers fight the intraspecific battles. The substances the ants use to mark their territory are hexadecanoic acid heptadecane. Hexadecanoic acid is a special compound produced by the metapleural glands and is always being released by the workers. Heptadecane is produced by the Dufours gland and is actively secreted as a territorial marker and also as am alarm pheromone. The overlying theme of leaf-cutting ant’s defense is to protect its food supply.
 
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