Shatrov A B
Parazitologiia. 1986 Jul-Aug;20(4):272-7.
When E. rotundata larvae parasitize the abdominal part of the body of their host (Clethrionomys glareolus), capsules with round terminal opening are formed from which hind part of the mite's body projects forwards. Organization of the capsules shows that their walls are formed by a substance (probably by larval saliva) which differs from host's tissues. At the bottom of the capsules there are larval adhesive sites with openings in the proximal parts of stylostomes which resemble in their structure these of N. vulgaris larvae. The latter do not form capsules when feeding on their natural hosts, Microtus arvalis. Proximal part of stylostome is formed in both cases by amorphous glutinous substance bearing imprints of mite's mobile digits of chelicerae and hypostome. Mouth parts of hungry mites and satiated larvae of both species differ only in relative sizes of constituent parts. Soft apical part of hypostome turns backwards during the feeding and forms a sucker. The feeding of larvae of trombiculids in capsules, which is formally regarded as ectoparasitism, can apparently be considered as a special type of parasitism.
当圆颚虱幼虫寄生于其宿主（棕背䶄）身体的腹部时，会形成带有圆形末端开口的囊，螨体的后部从囊中向前突出。囊的结构表明，其壁由一种物质（可能是幼虫唾液）形成，该物质与宿主组织不同。在囊的底部有幼虫附着部位，在口针近端有开口，其结构与普通新恙螨幼虫的口针相似。后者在以其自然宿主草原田鼠为食时不形成囊。在这两种情况下，口针近端均由无定形粘性物质形成，带有螨螯肢和下咽活动指节的印记。两种饥饿螨和饱食幼虫的口器仅在组成部分的相对大小上有所不同。下咽柔软的顶端部分在进食时向后弯曲并形成吸盘。在囊中恙螨幼虫的进食，虽然形式上被视为体外寄生，但显然可被视为一种特殊类型的寄生。
