Ruano Francisca, Hefetz Abraham, Lenoir Alain, Francke Wittko, Tinaut Alberto
Department of Animal Biology and Ecology, University of Granada, 18071 Granada, Spain.
J Insect Physiol. 2005 Oct;51(10):1158-64. doi: 10.1016/j.jinsphys.2005.06.005. Epub 2005 Aug 1.
In slave-making ants, the invasion of the host colony by newly mated queens is a critical stage. We studied the strategy used by Rossomyrmex minuchae queens to invade their host Proformica longiseta. Field observations revealed that queens enter the host nest unchallenged by the host workers in the vicinity of the nest entrance. Pre-usurpation queens were found to possess a highly inflated Dufour's gland, which considerably reduces in size after successful usurpation. Chemical analysis of these queen glands revealed tetradecanal to be the major product in pre-usurpation Rossomyrmex queens, but to be almost absent in queens that have been adopted by P. longiseta. We consequently hypothesized that tetradecanal is a repellent that is used by queens to prevent host worker aggression. We tested its repellent effect by attempting to deter starved, highly motivated workers from a droplet of honey. Tetradecanal indeed proved to be highly repellent both to host worker P. longiseta and non-host worker Formica selysi. It was even more powerful than limonene, a reported general ant repellent. These results are consistent with the hypothesis that R. minuchae queens use Dufour's gland secretion as a weapon during nest usurpation. The general use of tetradecanal as a defensive compound, and its seemingly non-specific repellent effect on ants, indicate that it may act as a general ant repellent. Its adoption by R. minuchae queens thus provides them with an efficient defensive and offensive chemical weapon during their long and risky search for new host nests.
在蓄奴蚁中，新交配的蚁后入侵宿主蚁群是一个关键阶段。我们研究了米氏罗蚁蚁后入侵其宿主长柄原蚁所采用的策略。野外观察发现，蚁后在巢穴入口附近进入宿主巢穴时未受到附近宿主工蚁的阻拦。研究发现，篡位前的蚁后拥有一个高度膨胀的杜氏腺，成功篡位后其大小会大幅减小。对这些蚁后腺体的化学分析表明，十四醛是篡位前米氏罗蚁蚁后的主要产物，但在被长柄原蚁接纳的蚁后中几乎不存在。因此，我们推测十四醛是一种驱避剂，蚁后用它来防止宿主工蚁的攻击。我们通过尝试阻止饥饿且积极性很高的工蚁接近一滴蜂蜜来测试其驱避效果。结果表明，十四醛对宿主长柄原蚁工蚁和非宿主赛氏蚁工蚁都具有很强的驱避作用。它甚至比柠檬烯更有效，柠檬烯是一种已报道的一般蚂蚁驱避剂。这些结果与米氏罗蚁蚁后在巢穴篡位期间利用杜氏腺分泌物作为武器的假设一致。十四醛作为一种防御性化合物的普遍使用，以及它对蚂蚁看似非特异性的驱避作用，表明它可能作为一种一般的蚂蚁驱避剂起作用。米氏罗蚁蚁后采用十四醛，从而在它们漫长而危险的寻找新宿主巢穴的过程中为它们提供了一种有效的防御和进攻性化学武器。
