Arrenurus truncatellus (O. F. Müller, 1776)

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 : 57

Arrenurus truncatellus (O. F. Müller, 1776)

( Fig. 39 )

Hydrachna truncatella O. F. Müller, 1776

Arrenurus oblongus Piersig, 1893

Material examined: 10 larvae deriving from 10 females.

Larvae large: idiosoma 236–264 µm long.

Dorsum: Dp large (DpL: 230–244 µm; DpW: 180–196 µm), egg-shaped, widest at mid-length. Antero-lateral indents small, slightly obtuse-angled, about 1/7 and 1/4 of plate’s length and width, respectively. DpW/ Mp1-Mp1 3.8. Lp2, Mh1 smooth. Mp1-Mp1 intermediate (48–50 µm), somewhat shorter than Mp2-Mp2 (51– 52 µm); Mp1-Lp2 short (37–40 µm). Venter: Median margins of CpI, CpII, CpIII 71–73, 32–34, 42– 44 µm, respectively; their ratios 2:1:1.5. C3, C4 pectinate; C1, C2 smooth. C1-CpIm (19–22 µm) about 3/4 of C4- CpIIIm (24–28 µm). C1-C2 intermediate (40–42 µm). Expp oval, somewhat wider than long. Exp located slightly below plate’s mid-point and below E2. Palps: PIII 1 bipectinate. Chelicerae: First segment bottleshaped (74–78 µm), one margin slightly convex, other slightly concave. Legs: Shorter than body; LI< LII < LIII ( Fig. 3 ). ITi8 thin, intermediate length; IITi10 very long; ITa13 located about1/4 of distance to proximal end of tarsus. Hosts: Dixidae , Culicidae ( Stechmann 1976 /77, 1978).

Figures

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

FIGURE 39. Arrenurus truncatellus: A—ventral side, B – dorsal plate, C – excretory pore plate, D—leg I (scale bars: A, B—100 µm; C, D—20 µm).