两种鼻白蚁之间的入侵关系

摘要

设计了5个实验以研究台湾乳白蚁(Coptotermes formosanus)和黄肢散白蚁(Reticulitermes flavipes)的种间斗争关系.所试白蚁采自阿拉巴马州.实验1将两组白蚁的兵蚁和工蚁以自然比例混合(台湾乳白蚁工蚁∶兵蚁=20∶5,黄肢散白蚁工蚁∶兵蚁=24∶1);实验2观察了双方同数量(各25头)工蚁的种间斗争能力;实验3观察两者同数量(各5头)兵蚁的种间斗争关系;实验4、5分别研究双方工蚁与兵蚁的斗争关系.因两种工蚁形态相似,所以在实验前用0.1% Nile blue A染过的滤纸饲喂一方白蚁24 h使虫体着色以便观察.所有实验在22℃,65% RH荧光灯下进行.每个实验将两方白蚁同时放入一培养皿中,观察至一方100%受伤,然后把培养皿移到培养箱内,24小时后统计死亡率.结果表明,实验一开始,双方的工蚁和兵蚁都立即进入残酷的厮杀斗争,台湾乳白蚁兵蚁和工蚁的斗争能力都明显强于黄肢散白蚁;兵蚁的斗争行为不受工蚁的影响,工蚁的斗争能力也不受兵蚁的制约.实验中台湾乳白蚁的工蚁与黄肢散白蚁的兵蚁攻击能力相当,但黄肢散白蚁的工蚁却远弱于台湾乳白蚁的兵蚁.上述结果说明,自然界中不可能出现此两种白蚁群体的偶然性融合;外来的台湾乳白蚁很可能在其群体建立的地区占据优势.%The aggressive relationship between the Formosan subterranean termite, Coptotermes formosanus, and the eastern subterranean termite, Reticulitermes flavipes, was investigated. Though both species displayed an immediate mutual aggressiveness, C. Formosanus was much more aggressive than R. Flavipes. Interspecific conflict involved both soldier and worker castes. Soldier's aggressive behaviors were not influenced by the absence of workers. Likewise, worker's aggressive behaviour was independent of the presence of soldiers. Interestingly, workers not only displayed strong aggression towards workers of the other species, but also vigorously attacked soldiers of the other species. The aggressive capability of C. Formosanus workers were comparable to that of R. Flavipes soldiers, but R. Flavipes workers were less aggressive than C. Formosanus soldiers in this study. These results indicate that mixed colonies of these two species can not be formed in nature by chance, and the exotic C. Formosanus is likely to prevail in areas where it has established.