Arrenurus conicus Piersig, 1894

Zawal, Andrzej, 2008, Morphological characteristics of water mite larvae of the genus Arrenurus Dugès, 1834, with notes on the phylogeny of the genus and an identification key, Zootaxa 1765 (1), pp. 1-75 : 53

Arrenurus conicus Piersig, 1894

( Fig. 35 )

Material examined: 10 larvae deriving from 10 females.

Larvae medium-sized: idiosoma 190–212 µm long.

Dorsum: Dp relatively small (DpL: 170–194 µm; DpW: 146–170 µm), egg-shaped, widest at about 1/3 distance from anterior margin; distinctly narrowing posteriorly; posterior margin rounded. Antero-lateral indents relatively shallow, obtuse-angled, about 1/5 and 1/4 of Dp length and width, respectively. Microrelief cells elongated. DpW/Mp1-Mp1 5.0. Lp2, Mh1 smooth. Mp1-Mp1 short (30–34 µm), shorter than Mp2-Mp2 (38–46 µm); Mp1-Lp2 intermediate (38–42 µm). Venter: CpIm (68–72 µm) clearly longest, CpIIm shortest (22–28 µm) and CpIIIm intermediate (40–46 µm). CpIm:CpIIm:Cpm ratio 2.8:1:1.7. Setae on Cp smooth, relatively thick and long. C1-CpIm (21–26 µm) identical to or somewhat longer than C4-CpIIIm (21–22 µm). C1-C2 moderately long (40–45 µm). Expp triangular, margins convex, width almost equal to length. Exp located distinctly below plate’s mid-point and slightly below E2. Palps: PIII 1 bipectinate. Chelicerae: First segment cylindrical (73–77 µm), narrowing anteriorly, one margin straight or somewhat concave, other slightly convex. Legs: Somewhat shorter than body; LI< LII < LIII ( Fig. 3 ). ITi7 thick; ITi8 long; IITi8 long, smooth, thin; IITi10, IIITi10 located at centre of tibia; IIITa3 located near centre of tarsus.

Figures

FIGURE 3. Diagram of proportions of leg (LI<LII<LIII) and body length.

FIGURE 35. Arrenurus conicus: A—ventral side, B—dorsal plate, C—excretory pore plate, D—leg III (scale bars: A, B—100 µm; C, D—20 µm).