Chiu Chun-I, Yeh Hsin-Ting, Li Pai-Ling, Kuo Chih-Yu, Tsai Ming-Jer, Li Hou-Feng
Department of Entomology, National Chung Hsing University, Taichung, Taiwan.
The Experimental Forest Administration, College of Bio-Resources and Agriculture, National Taiwan University, Jhushan Township, Nantou County, Taiwan.
Environ Entomol. 2018 Dec 7;47(6):1509-1516. doi: 10.1093/ee/nvy140.
Fungus-growing termites are major contributors to litter decomposition and an agriculture pest in tropical and subtropical Africa and Asia. The foraging behavior of fungus-growing termites was hypothesized to be seasonal and may associate with climatic factors and the occurrence of natural enemies. In this study, we tested the effects of climatic factors and the presence of ants on the foraging activity of the fungus-growing termite Odontotermes formosanus (Shiraki) (Blattodea: Termitidae). Termite-foraging activities were quantified monthly based on the number of wood stakes occupied, amount of wood consumed, and foraging population size. The rate of wood-stake decomposition was measured by monitoring 484 wood stakes in a tropical forest over the course of nearly 6 yr. The results revealed that temperature and rainfall are the major climatic factors influencing the foraging seasonality of O. formosanus. Termites occupied fewer wood stakes during hot-wet seasons when fewer ants were present. The results of a path analysis supported that termite-foraging seasonality correlated mainly with climatic factors rather than the presence of ants. A new foraging hypothesis, the eat-and-run strategy, is proposed to explain the inconsistent seasonal foraging behaviors observed in fungus-growing termites.
培菌白蚁是热带和亚热带非洲及亚洲枯枝落叶分解的主要贡献者,也是农业害虫。据推测,培菌白蚁的觅食行为具有季节性,可能与气候因素和天敌的出现有关。在本研究中,我们测试了气候因素和蚂蚁的存在对培菌白蚁黑翅土白蚁(Shiraki)(蜚蠊目:白蚁科)觅食活动的影响。基于被占据木桩的数量、消耗的木材量和觅食群体大小,每月对白蚁的觅食活动进行量化。通过在近6年的时间里监测热带森林中的484根木桩,测量木桩的分解速率。结果表明,温度和降雨是影响黑翅土白蚁觅食季节性的主要气候因素。在炎热潮湿季节,当蚂蚁数量较少时,白蚁占据的木桩也较少。通径分析结果支持白蚁觅食季节性主要与气候因素相关,而非与蚂蚁的存在相关。我们提出了一种新的觅食假说——“吃了就跑”策略,以解释培菌白蚁观察到的不一致的季节性觅食行为。