Florane Christopher B, Bland John M, Husseneder Claudia, Raina Ashok K
Formosan Subterranean Termite Research Unit, ARS, USDA, New Orleans, Louisiana, USA.
J Chem Ecol. 2004 Dec;30(12):2559-74. doi: 10.1007/s10886-004-7950-2.
In most social insects, intercolonial and interspecific aggression are expressions of territoriality. In termites, cuticular hydrocarbons (CHCs) have been extensively studied for their role in nestmate recognition and aggressive discrimination of nonnest-mates. More recently, molecular genetic techniques have made it possible to determine relatedness between colonies and to investigate the influence of genetics on aggression. In the Formosan subterranean termite, Coptotermes formosanus, however, the role of CHCs and genetic relatedness in inter-colony aggression has been ambiguous, suggesting the involvement of additional factors in nest-mate recognition. In this study we assess the range of aggression in this termite species and characterize the influence of genetic relatedness, CHC profiles and diet on aggression levels. We collected four colonies of C. formosanus, feeding either on bald cypress or birch, from three locations in Louisiana. Inter-colony aggression ranged from low to high. Differences in CHC profiles, as well as genetic distances between colonies determined by using microsatellite DNA markers, showed no significant correlation with aggression. However, termite diet (host tree) played a significant role in determining the level of aggression. Thus, two distantly related colonies, each feeding on different diets, showed high aggression that significantly diminished if they were fed on the same wood in the laboratory (spruce). Using headspace solid phase microextraction, we found three compounds from workers fed on birch that were absent in workers fed on spruce. Such diet-derived chemicals may be involved in the complex determination of nest-mate recognition in C. formosanus.
在大多数社会性昆虫中，群体间和种间攻击行为是领地性的表现。在白蚁中，表皮碳氢化合物（CHCs）在识别同巢伙伴和对非同巢伙伴进行攻击区分方面的作用已得到广泛研究。最近，分子遗传学技术已使确定群体间的亲缘关系以及研究遗传学对攻击行为的影响成为可能。然而，在台湾乳白蚁（Coptotermes formosanus）中，CHCs和遗传亲缘关系在群体间攻击行为中的作用一直不明确，这表明在同巢伙伴识别中还涉及其他因素。在本研究中，我们评估了这种白蚁的攻击行为范围，并描述了遗传亲缘关系、CHC图谱和食物对白蚁攻击水平的影响。我们从路易斯安那州的三个地点收集了四个台湾乳白蚁群体，这些群体分别以落羽杉或桦木为食。群体间的攻击行为程度不一，从低到高都有。CHC图谱的差异，以及使用微卫星DNA标记确定的群体间遗传距离，均与攻击行为无显著相关性。然而，白蚁的食物（寄主树）在决定攻击水平方面发挥了重要作用。因此，两个亲缘关系较远且各自以不同食物为食的群体，表现出强烈的攻击性，但如果在实验室中给它们喂食相同的木材（云杉），其攻击性会显著降低。通过顶空固相微萃取，我们发现以桦木为食的工蚁体内有三种化合物，而以云杉为食的工蚁体内没有。这些源自食物的化学物质可能参与了台湾乳白蚁同巢伙伴识别的复杂过程。
