Summary The dagger nematodes of the longidorids can cause diseases of various agronomic and horticultural crops, and are consisted of more than 260 valid species. In a forest survey of ecotypes of longidorid nematodes, from the root zone soil of Brant’s oak, (Quercus brantii Lindl.) and hawthorn (Crataegus aronia L.) trees, three species of Xiphinema americanum group namely Xiphinema pachtaicum, X. oxycaudatum and X. plesiopachtaicum were collected and studied based on their morphological and morphometric characters. X. pachtaicum is prevalent Xiphinema species in Iran. In this paper additional data for X. oxycaudatum and X. plesiopachtaicum species are presented. X. plesiopachtaicum is a new record for nematode fauna of Iran.

中文翻译：

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来自伊朗洛雷斯坦省的三种美洲剑齿虫群复合体（线虫科：长臂虫科）

小结 长臂猿的匕首线虫可引起多种农艺和园艺作物的病害，由260多种有效种组成。在对长臂猿线虫生态型的森林调查中，从布兰特橡树 (Quercus brantii Lindl.) 和山楂 (Crataegus aronia L.) 树的根区土壤中，美洲剑线虫属的三个物种即 Xiphinema pachtaicum、X. oxycaudatum 和 X . plesiopachtaicum 被收集和研究基于它们的形态学和形态学特征。X. pachtaicum 是伊朗流行的 Xiphinema 物种。在本文中，提供了 X. oxycaudatum 和 X. plesiopachtaicum 物种的其他数据。X. plesiopachtaicum 是伊朗线虫动物群的新记录。