Feeding habits of Hymenoptera and Isoptera in a tropical rain forest as revealed by nitrogen and carbon isotope ratios
Feeding habits of Hymenoptera and Isoptera in a tropical rain forest as revealed by nitrogen and carbon isotope ratios
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DOI：
10.1007/s00040-011-0159-9
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发表时间：
2011-08-01
期刊：
影响因子：
1.3
通讯作者：
Itioka, T.
中科院分区：
文献类型：
--
作者：
Hyodo, F.;Takematsu, Y.;Itioka, T.
膜翅目昆虫（蚂蚁、蜜蜂和黄蜂）和等翅目昆虫（白蚁）在热带生态系统中的功能作用已得到公认，但其详细的摄食习性尚不清楚。为了研究这些群体的摄食习性，我们测量了在马来西亚沙捞越热带雨林中收集的膜翅目昆虫（12科，1千分之一的yen16属和1千分之一的yen32种）和等翅目昆虫（1科，10种）的氮(N)和碳(C)稳定同位素比率（δ N-15和δ C-13）。我们将这些昆虫的同位素特征与之前报道的在同一森林中收集的其他消费者的同位素特征进行了比较。这些昆虫的N-15和C-13值与其他昆虫的N-15和C-13值重叠，表明它们在森林中获得了不同的C和N来源。蚂蚁和白蚁的δ N-15值表明，它们的取食习性分别从草食（即依赖蜜露和花蜜）到捕食，从食木到食土。此外，小黄蜂的N-15值在-0.1 ~ 8.6℃之间变化很大，表明它们的摄食习性也从杂食性到捕食性。蚁种Camponotus gigas的δ C-13值与无脊椎腐食动物和杂食动物相似，而与无脊椎食草动物相似，尽管该蚁种的食物主要由蜜露组成。这种差异表明蚂蚁使用碳水化合物作为能量来源，其同位素特征在身体组织中没有很好地保留。掠食性军蚁（Leptogenys diminuta）和食土白蚁（diuspiditermes nemorosus）的δ N-15和δ C-13值差异不显著，说明营养水平和食土基质腐殖化都能增加陆食者的同位素特征。
Despite the recognition of the functional role of Hymenoptera (ants, bees and wasps) and Isoptera (termites) in tropical ecosystems, their detailed feeding habits are not well known. To examine the feeding habits of these groups, we measured nitrogen (N) and carbon (C) stable isotope ratios (delta N-15 and delta C-13) of hymenopterans (12 families, a parts per thousand yen16 genera and a parts per thousand yen32 species) and isopterans (one family and 10 species) collected in a tropical rain forest, Sarawak, Malaysia. We compared the isotopic signatures of these insects to those previously reported for other consumers collected in the same forest. The delta N-15 and delta C-13 values of these insects overlapped with those of the other consumers, indicating that they have access to diverse C and N sources in the forest. The delta N-15 values of ants and termites indicated that their feeding habits range along a continuum from herbivory (i.e. dependent on honeydew and nectar) to predation and from wood-feeders to soil-feeders, respectively. In addition, the delta N-15 values of wasps varied greatly from -0.1aEuro degrees (Braconidae sp.) to 8.6aEuro degrees (Bembix sp.), suggesting that their feeding habits also range from omnivory to predation. The ant species Camponotus gigas had delta C-13 values similar to those of invertebrate detritivores and omnivores rather than to those of invertebrate herbivores, although the diet of this species consists mostly of honeydew. This discrepancy suggests that the ant uses carbohydrates as an energy source, the isotopic signatures of which are not well retained in the body tissues. Values of both delta N-15 and delta C-13 of the predatory army ant Leptogenys diminuta and the soil-feeding termite Dicuspiditermes nemorosus did not differ significantly, indicating that both trophic level and the humification of feeding substrates can increase the isotopic signatures of terrestrial consumers.