Marler Thomas E, Matanane Frankie C, Terry L Irene
Western Pacific Tropical Research Center, University of Guam, Mangilao, GU, USA.
School of Biological Sciences, University of Utah, Salt Lake City, UT, USA.
Commun Integr Biol. 2020 Jun 2;13(1):74-83. doi: 10.1080/19420889.2020.1774310.
Guam's established population of non-native coconut rhinoceros beetle (CRB, L.) began creating burrows in stem apices of several cycad species in a managed garden. We conducted an island-wide survey to determine the spatial patterns of CRB burrowing of stems of . We also measured starch of healthy and unhealthy coconut leaf tissue and compared this with starch of cycad stem tissue. The starch concentration of the central unexpanded leaf in healthy Philippine coconut trees was ≈90 mg·g, and that of unhealthy Guam coconut trees was ≈40 mg·g. The starch concentration of the tissue within the CRB burrow locations on trees was 145 mg·g. Burrowing of was restricted to female CRB adults and was found throughout the full latitudinal gradient of Guam. Our findings indicate Guam's unhealthy coconut trees are no longer nutrient-dense, and the female CRB population may have exhibited a phylogenetically distant host shift to the abundant plants for a starch-rich diet within the concepts of the 'ecological fitting' hypothesis. We add proximity to coconut tree habitats as a new threat to Guam's endangered population.
关岛已有的非本地椰心叶甲种群（CRB， ）开始在一个管理花园中几种苏铁科植物的茎尖处挖掘洞穴。我们进行了全岛范围的调查，以确定CRB在 茎上挖掘洞穴的空间模式。我们还测量了健康和不健康的椰子叶组织中的淀粉含量，并将其与苏铁茎组织中的淀粉含量进行比较。健康的菲律宾椰子树中未展开的中心叶的淀粉浓度约为90毫克·克，而不健康的关岛椰子树的淀粉浓度约为40毫克·克。 树上CRB洞穴位置内组织的淀粉浓度为145毫克·克。 的挖掘仅限于雌性CRB成虫，在关岛的整个纬度梯度上都有发现。我们的研究结果表明，关岛不健康的椰子树不再营养丰富，雌性CRB种群可能在“生态适应”假说的概念范围内，向丰富的 植物表现出系统发育上较远的宿主转移，以获取富含淀粉的食物。我们将靠近椰子树栖息地作为对关岛濒危 种群的一种新威胁。
