Csata Enikő, Bernadou Abel, Rákosy-Tican Elena, Heinze Jürgen, Markó Bálint
Hungarian Department of Biology and Ecology, Babeş-Bolyai University, 400006 Cluj-Napoca, Clinicilor 5-7, Romania.
Department of Zoology and Evolutionary Biology, University of Regensburg, D-93040 Regensburg, Germany.
J Insect Physiol. 2017 Apr;98:167-172. doi: 10.1016/j.jinsphys.2017.01.004. Epub 2017 Jan 10.
Parasite infection often results in alterations in host behaviour. These changes vary greatly in their magnitude, from slight shifts in the time spent by the host performing a given activity to the appearance of novel behaviours. The effects of parasites can differ with the age and the physiological condition of the host. Rickia wasmannii is an ectoparasitic fungal symbiont in Myrmica ants that covers the whole body surface of the host and reduces its lifespan. The fungus is present in both young and old individuals, making it an optimal subject for the study of age-related parasitic effects. We tested the effect of fungal infection on the locomotory activity of the Myrmica scabrinodis ant in different age categories. The fat content of workers was measured as a proxy for their physiological status. Based on our findings, old workers bore more thalli and were leaner than young individuals, while they tended to move at higher speeds and with a lower degree of meandering. Young individuals covered smaller distances, at slower speeds and with a higher degree of meandering. Contrary to our expectations, the infection intensity of R. wasmannii affected neither the fat content nor the locomotory activity of ant workers. However, the two age classes seem to have different strategies with regards to the relationship between fat content and distance covered. Our results suggest that characteristics of locomotory activity differ between the age classes in many respects, and are also influenced by their physiological status, but parasitism by R. wasmannii does not seem to have a straightforward effect on any of the variables studied.
寄生虫感染通常会导致宿主行为发生改变。这些变化在程度上差异很大，从宿主进行特定活动所花费时间的轻微变化到新行为的出现。寄生虫的影响会因宿主的年龄和生理状况而有所不同。瓦氏里克氏菌是蚁属蚂蚁中的一种体表寄生真菌共生体，它覆盖宿主的整个体表并缩短其寿命。这种真菌在年轻和年老个体中都存在，使其成为研究与年龄相关的寄生效应的理想对象。我们测试了真菌感染对不同年龄类别的粗糙蚁运动活性的影响。测量工蚁的脂肪含量作为其生理状态的指标。根据我们的研究结果，年老的工蚁携带的菌体更多，且比年轻个体更瘦，而它们往往移动速度更快且曲折程度更低。年轻个体移动的距离更小，速度更慢且曲折程度更高。与我们的预期相反，瓦氏里克氏菌的感染强度既不影响工蚁的脂肪含量也不影响其运动活性。然而，在脂肪含量和移动距离之间的关系方面，这两个年龄组似乎有不同的策略。我们的结果表明，运动活性的特征在不同年龄组之间在许多方面存在差异，并且也受到其生理状态的影响，但瓦氏里克氏菌的寄生似乎对所研究的任何变量都没有直接影响。
