直翅目虫草（肉座菌目）：物种多样性及其与寄主的关系

迄今为止,以直翅目昆虫为寄主的虫草共报道25种,本研究详细介绍了它们的种类、寄主与分布,并给出了相关的分类学注释。ITS和tef1-α基因联合数据的分子系统发育显示,直翅目虫草分别隶属于白僵菌属Beauveria、绿僵菌属Metarhizium和线虫草属Ophiocordyceps 3个属。基于直翅目昆虫六大类群的生态习性特点,分析并讨论了直翅目虫草物种多样性与寄主的关系。以两种白僵菌Beauveria及戴氏虫草Metacordyceps taii（贵州绿僵菌Metarhizium guizhouense的异名）为例,介绍了虫草的根状菌索,一种介于子实体和孢梗束形体之间的根须状结构。种类修订：蟋螽白僵菌新组合Beauveria grylli comb. nov. ≡ 蟋蟀虫草Cordyceps grylli = Beauveria loeiensis,Beauveria kirkii comb. nov. ≡ Cordyceps kirkii。寄主更正：蟋螽白僵菌的寄主由原来的蟋蟀成虫（蟋蟀科Gryllidae）更正为螽斯（蟋螽）若虫（蟋螽科Gryllacrididae）,蟋蟀线虫草Ophiocordyceps tettigonia 寄主由原来的螽斯成虫（螽斯科Tettigoniidae：螽斯属Tettigonia）更正为蟋蟀成虫（蟋蟀科）。

Species diversity and host associations of cordyceps (Hypocreales) parasitic on Orthoptera insects

Totally 25 cordyceps (Cordyceps sensu lato) species have been reported on Orthoptera insects. Their hosts and distributions are reviewed and taxonomical notes for species are given. Using combined ITS and tef1-α sequence dataset, molecular phylogeny of cordyceps species on Orthoptera insects was constructed. Current species were assigned to three clades: the Beauveria, the Metarhizium and the Ophiocordyceps clades. Based on ecology and habits of the six well known groups of Orthoptera, the relation between species diversity and host of Orthoptera cordyceps is discussed. The rhizomorphs of cordyceps, a special root-like structure situated somewhere between fruiting bodies and synnemata, were observed on Beauveria spp. and Metacordyceps taii (syn. Metarhizium guizhouense). Beauveria grylli comb. nov. ≡ Cordyceps grylli = Beauveria loeiensis and Beauveria kirkii comb. nov. ≡ Cordyceps kirkii are proposed. The hosts of Beauveria grylli and Ophiocordyceps tettigonia are corrected.