Dejean Alain, Beugnon Guy
Laboratoire d'Ethologie Fxpérimentale et Comparée (URA CNRS No. 667), Université Paris XIII, Av. Jean Baptiste Clément, F-93430, Villetaneuse, France.
Laboratoire d'Ethologie et Psychologie Animale (URA CNRS No. 1837), Université Toulouse III, 118 route de Narbonne, F-31062, Toulouse, France.
Oecologia. 1996 Apr;106(1):57-62. doi: 10.1007/BF00334407.
In this study we report a case of ant-trail following by lycaenid caterpillars. Euliphyra mirifica and E. leucyana caterpillars are involved in a commensal association with the weaver ant Oecophylla longinoda. The host nests are made with leaves which over the course of time dry out or are broken open by storms, forcing the ants to migrate and build a new nest elsewhere. Euliphyra caterpillars are stimulated by recruitment behaviour which triggers the migration of their host. They then follow the host trails leading to the new nesting site. Laboratory experiments showed that these caterpillars are able to follow host trails under varied conditions: (1) fresh trails actually used by workers, (2) fresh trails in the absence of workers, (3) heterocolonial, 2-month-old trails, and (4) fresh trails washed with water (to simulate the effect of tropical rains). They can also bridge trail gaps of more than 1 cm. Under natural conditions, the trails are frequently situated along thin twigs. The forward progress of the ants in such a situation is not impeded by the presence of large Euliphyra larvae. Workers just climb over the caterpillars, even on larger trails where there is enough room to pass alongside them. This suggests that an allomone is secreted on the dorsal part of the caterpillars. When crawling along heterocolonial trails, the caterpillars are not attacked, even if about 21% of the workers from the new colony spread their mandibles when encountering them. They are then adopted and are admitted to the nest of the new host colony of O. longinoda.
在本研究中，我们报告了一例小灰蝶幼虫追踪蚁道的案例。奇妙优灰蝶和白优灰蝶的幼虫与织叶蚁（长结蚁）存在共生关系。宿主蚁巢由树叶构成，随着时间推移树叶会干枯，或被风暴吹开，迫使蚂蚁迁移并在其他地方建造新巢。优灰蝶幼虫会受到招募行为的刺激，这种行为会触发其宿主的迁移。然后它们会沿着宿主的蚁道前往新的筑巢地点。实验室实验表明，这些幼虫能够在多种条件下追踪宿主蚁道：（1）工蚁实际使用的新鲜蚁道；（2）没有工蚁的新鲜蚁道；（3）来自不同蚁群、两个月大的蚁道；（4）用水冲洗过的新鲜蚁道（以模拟热带降雨的效果）。它们还能跨越超过1厘米的蚁道间隙。在自然条件下，蚁道常常沿着细树枝分布。在这种情况下，大优灰蝶幼虫的存在并不会阻碍蚂蚁前进。工蚁会直接从幼虫身上爬过去，即使在有足够空间可以从它们旁边通过的较宽蚁道上也是如此。这表明幼虫背部会分泌一种异种信息素。当沿着来自不同蚁群的蚁道爬行时，幼虫不会受到攻击，即使新蚁群中约21%的工蚁在遇到它们时会张开下颚。然后幼虫会被接纳，并被允许进入长结蚁新宿主蚁群的巢穴。
