Emery Virginia J, Tsutsui Neil D
Department of Environmental Science, Policy and Management, University of California, Berkeley, CA, 94720, USA.
J Chem Ecol. 2016 Apr;42(4):277-85. doi: 10.1007/s10886-016-0692-0. Epub 2016 Apr 29.
Chemical recognition systems are crucial for maintaining the unity of social insect colonies. It has been proposed that colonies form a common chemical signature, called the gestalt odor, which is used to distinguish colony members and non-members. This chemical integration is achieved actively through social interactions such as trophallaxis and allogrooming, or passively such as through exposure to common nest material. When colonies are infiltrated by social parasites, the intruders often use some form of chemical mimicry. However, it is not always clear how this chemical mimicry is accomplished. Here, we used a three-species nesting symbiosis to test the differences in chemical integration of mutualistic (parabiotic) and parasitic ant species. We found that the parasite (Solenopsis picea) obtains chemical cues from both of the two parabiotic host ant species. However, the two parabiotic species (Crematogaster levior and Camponotus femoratus) maintain species-specific cues, and do not acquire compounds from the other species. Our findings suggest that there is a fundamental difference in how social mutualists and social parasites use chemicals to integrate themselves into colonies.
化学识别系统对于维持社会性昆虫群落的统一性至关重要。有人提出，群落会形成一种共同的化学特征，称为整体气味，用于区分群落成员和非成员。这种化学整合通过诸如交哺和互舐等社会互动积极实现，或者通过接触共同的巢穴材料等被动方式实现。当群落被社会寄生虫侵入时，入侵者通常会采用某种形式的化学拟态。然而，这种化学拟态是如何实现的并不总是很清楚。在这里，我们利用一种三种物种的筑巢共生关系来测试互利共生（共生）和寄生蚂蚁物种在化学整合方面的差异。我们发现，寄生虫（黑褐小家蚁）从两种共生宿主蚂蚁物种中都获取化学线索。然而，两种共生物种（淡色举腹蚁和大腿木工蚁）保持物种特异性线索，并且不会从其他物种获取化合物。我们的研究结果表明，社会互利共生者和社会寄生虫在如何利用化学物质将自身融入群落方面存在根本差异。
