一种新的僵尸蚂蚁行为被揭示：聚集在树干上。

A new zombie ant behavior unraveled: Aggregating on tree trunks.

机构信息

Department of Entomology, Pennsylvania State University, 501 ASI Building, University Park, PA 16802, USA.

School of Forest Resources and Conservation, University of Florida, 136 Newins-Ziegler Hall, Gainesville, FL 32611, USA.

出版信息

J Invertebr Pathol. 2020 Nov;177:107499. doi: 10.1016/j.jip.2020.107499. Epub 2020 Oct 28.

DOI:10.1016/j.jip.2020.107499

PMID:33129891

Abstract

Hosts can be manipulated by parasites to move to locations advantageous for onward transmission. To investigate the role of behavioral manipulation in creating transmission hotspots, we studied the distribution of zombie turtle ants in the Amazon rainforest. The turtle ant Cephalotes atratus nests and mostly forages in the canopy, but is found at the base of trees when infected with the zombie ant fungus Ophiocordyceps kniphofioides. We found 626 infected cadavers on 14.8% of 162 trees sampled. Cadavers were highly aggregated on the surface of the trees, explained by behavioral observations indicating infected ants as slightly attracted to zombie ant cadavers on a tree. From 1,726 h of camera footage, we recorded the removal of three zombie ant cadavers by live ants. The number of removals compared to the density of infected individuals indicates the base of a tree as an escape from the evolved ability of social insects to recognize and treat disease inside the nest, allowing the parasite to continuously remain in the environment.

摘要

宿主可能会被寄生虫操纵而转移到有利于进一步传播的位置。为了研究行为操纵在形成传播热点中的作用，我们研究了亚马逊雨林中僵尸龟蚁的分布。龟蚁 Cephalotes atratus 筑巢并主要在树冠层觅食，但当感染僵尸蚁真菌 Ophiocordyceps kniphofioides 时，会在树下被发现。我们在 162 棵抽样树木中的 14.8%上发现了 626 具感染的尸体。尸体在树上的表面高度聚集，这可以通过行为观察来解释，即感染的蚂蚁会被树上的僵尸蚁尸体稍微吸引。从 1726 小时的摄像机镜头中，我们记录了三只僵尸蚁尸体被活蚂蚁移走。与感染个体密度相比，移走的数量表明树的底部是一种逃避进化后的社会昆虫在巢内识别和处理疾病的能力的方式，使寄生虫能够持续存在于环境中。