伊大头蚁蚁巢的结构与分布

伊大头蚁Pheidole yeensis是舞草Codariocalyx motorius种子的主要搬运者, 在舞草的扩散中起着重要作用。2000年在西双版纳和思茅地区景谷县对伊大头蚁种群数量、蚁巢结构与分布进行了调查。结果表明:伊大头蚁主要在土壤中筑巢,深度可达地下50 cm;每巢蚁量一般在2 000～3 000头,最多的可达万头;伊大头蚁大多在海拔1 000～1 200 m的山腰筑巢, 以西坡的蚁巢密度最大,南坡次之,北坡最少;在丢荒2～3年的地里筑巢最多,其次为玉米和花生地,在森林里筑巢的相对较少;伊大头蚁的蚁巢呈均匀分布,但巢群间相互排斥。伊大头蚁筑巢生境与舞草生长的环境基本一致,蚁巢结构与蚁量有利于舞草的扩散与建群。

The structure and distribution of Pheidole yeensis nests

Codariocalyx motorius (Houtt.) Ohashi grows as a common perennial pioneer plant in areas of slash and burn cultivation in the tropical and subtropical mountains of Yunnan Province, China. There is mutualism between the ant, Pheidole yeensis and C. motorius. The plant provides the ant with food, and the ant carries and disperses the seeds of the C. motorius. The structure and distribution of Pheidole yeensis nests in Yunnan Province was investigated in 2000.The results show that P. yeensis mainly builds nests in soil at an altitude of 1 000-1 200 m. Nests can extend down to a depth of 50 cm with the usual depth being 20-40 cm. The number of the ants per nest ranged from 2 000 to 3 000, with the maximum being more than 10 thousand. In fields that had been abandoned for 2-3 years at an altitude of 1 000-1 200m, most nests were found on western slopes, southern slopes having the next highest nest density, and northern slopes the least. The number of nests was highest in fields that had been abandoned for 2-3 years with the next highest abundance recorded in corn and peanut fields and the lowest in forest. The spatial istribution of P. yeensis nests was regular, but ant colonies repelled one another.