Rocha Carlos Frederico Duarte, Bergallo Helena Godoy
Departamento de Zoologia, Instituto de Biologia, UNICAMP, C.P. 6109, 13081, Campinas, SP, Brazil.
Oecologia. 1992 Aug;91(2):249-252. doi: 10.1007/BF00317792.
The effect of defence force size in colonies of the ant Azteca muelleri on the time spent to localize, attack and expel the specialized herbivorous beetle Coelomera ruficornis from Cecropia pachystachya bushes was studied in an area of Atlantic forest in northeastern Brazil. Our results show that Azteca muelleri expel Coelomera ruficornis from Cecropia pachystachya and that the number of ants leaving a colony (defence force size) is negatively correlated with the residence time of an adult beetle on the plant. Colonies with larger defence forces recruited larger numbers of ants, resulting in faster herbivore discovery (r =0.80; n=17; P<0.001) and reduced herbivore residence time on a leaf (r =0.79 n=23; P<0.001) before being driven off by the ants. We also found a negative and significant relationship between herbivore damage on leaves and ant colony size (r =0.28; n=17; P<0.05). We conclude that larger colonies have more individuals available to patrol a plant and recruit defenders toward herbivores. This reduces the time spent to locate and expel susceptible herbivores from the plant. Since the plant probably benefits from reduced herbivory and the plant provides food for the ants, the association between Azteca muelleri and Cecropia pachystachya appears mutualistic.
在巴西东北部的一片大西洋森林地区，研究了穆勒阿兹特克蚁（Azteca muelleri）蚁群的防御力量规模对定位、攻击并驱赶专食性食草甲虫红角腔背叶甲（Coelomera ruficornis）使其离开巴拿马伞树（Cecropia pachystachya）灌木丛所需时间的影响。我们的研究结果表明，穆勒阿兹特克蚁会将红角腔背叶甲从巴拿马伞树上驱赶出去，且离开蚁群的蚂蚁数量（防御力量规模）与成年甲虫在植株上的停留时间呈负相关。防御力量较大的蚁群招募的蚂蚁数量更多，这使得食草动物能被更快发现（r = 0.80；n = 17；P < 0.001），并且在被蚂蚁赶走之前，食草动物在叶片上的停留时间缩短（r = 0.79；n = 23；P < 0.001）。我们还发现叶片上的食草动物损害与蚁群规模之间存在显著的负相关关系（r = 0.28；n = 17；P < 0.05）。我们得出结论，较大的蚁群有更多个体可用于在植株上巡逻，并向食草动物招募防御者。这减少了定位并驱赶植株上易受攻击的食草动物所需的时间。鉴于植株可能因食草动物数量减少而受益，且植株为蚂蚁提供食物，穆勒阿兹特克蚁与巴拿马伞树之间的关联似乎是互利共生的。
