Department of Parasitology, Institute of Ecology and Biological Resources, Vietnam Academy of Science and Technology, Ha Noi, Vietnam.
Graduate University of Science and Technology, Vietnam Academy of Science and Technology, Ha Noi, Vietnam.
J Helminthol. 2023 Feb 17;97:e23. doi: 10.1017/S0022149X22000827.
Various dung beetle species of the family Scarabaeidae have been reported as intermediate hosts of from different geographical locations, but there has been no data from south-east Asian countries. In the present study in Vietnam, by using morphological and molecular approaches, we identified the third-stage larvae of for the first time in two dung beetle species, and , adding them as new intermediate hosts of this nematode. In addition, both beetle species were infected with larvae of another spirurid nematode of sp. At large magnifications above 200×, these two spirurid larvae can be differentiated from each other by their body size (1880-2662 vs. 1417-1635 μm) and detailed morphological features of the anterior and posterior ends, such as the length of the buccal cavity, the position of the nerve ring and excretory pore, and tail characters. However, it is difficult to distinguish them at a lower magnification due to their minute size. Moreover, morphometric data of larvae vary among reports and the body length may overlap with that of sp., thus, misidentification may occur, indicating the necessity of careful examination for accurate identification. The findings of the present study also supposed that larvae of and more spirurid nematodes may be concurrently found in various dung beetle species, including and , in other south-east Asian countries. Thus, more investigations in various countries should be conducted to identify spirurid larvae from dung beetles in order to fully understand their role as intermediate hosts of and other spirurid nematodes.
已报道多种粪金龟科（Scarabaeidae）甲虫种类是来自不同地理位置的旋尾目线虫（Spirurida）的中间宿主，但来自东南亚国家的数据尚缺。本研究在越南，通过形态学和分子方法，首次在两种粪金龟（ 和 ）中鉴定出旋尾目线虫的第三期幼虫，将它们添加为该线虫的新中间宿主。此外，这两种甲虫均感染了另一种旋尾线虫（ sp.）的幼虫。在 200×以上的大放大倍数下，这两种旋尾线虫幼虫可以通过其体长（1880-2662μm 与 1417-1635μm）和前端和后端的详细形态特征，如口腔腔的长度、神经环和排泄孔的位置以及尾部特征来区分。然而，由于它们的微小尺寸，在较低的放大倍数下很难区分它们。此外，旋尾目幼虫的形态测量数据在不同报道中存在差异，并且体长可能与 sp.的体长重叠，因此可能会发生误识别，这表明需要仔细检查以进行准确识别。本研究的结果还表明， 和更多的旋尾线虫幼虫可能同时存在于各种粪金龟种类中，包括 和 ，在其他东南亚国家也是如此。因此，应在各国开展更多调查，以从粪金龟中鉴定旋尾线虫幼虫，以便充分了解它们作为旋尾目线虫和其他旋尾线虫的中间宿主的作用。
