Arrenurus castaneus Neuman, 1880

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 : 58

Arrenurus castaneus Neuman, 1880

( Fig. 40 )

Material examined: 10 larvae deriving from 5 females.

Larva very similar to A. truncatellus . Slight differences in dorsal plate shape. Idiosoma 230–238 µm long.

Dorsum: Dp large (DpL: 222–230 µm; DpW: 174–184 µm), egg-shaped, widest at mid-length. Antero-lateral indents small, almost right-angled, reaching to about 1/7 and 1/4 of plate’s length and width, respectively. Anterior margin of dorsal plate, relative to its width, slightly wider than in A. truncatellus . DpW/Mp1-Mp1 3.8. Lp2, Mh1 smooth. Mp1-Mp1 (45–52 µm) distinctly shorter than Mp2-Mp2 (54–61 µm); Mp1-Lp2 intermediate (41–45 µm). Venter: Median margins of CpI, CpII, CpIII measure 66–69, 28–31, 50– 54 µm, respectively, their ratio 2:1:1.5. C3, C4 pectinate, C1, C2 smooth. C1-CpIm (18–20 µm) about 3/4 of C4-CpIIIm (24–28 µm). C1-C2 intermediate (44–49 µm). Legs: Shorter than body; LI< LII = LIII ( Fig. 4 ). ITa13 located closer to mid-point of tarsus than in A. truncatellus , IITi10, IIITi10 located closer to distal end of tibia. IITi10, IIITa13 smooth; ITa13 located about 1/3 of distance to proximal end of tarsus.

Figures

FIGURE 4. Diagram of proportions of leg (LI<LII=LIII) and body length.

FIGURE 40. Arrenurus castaneus: A—ventral side, B—dorsal plate, C—excretory pore plate, D—leg I (scale bars: A, B—100 µm; C, D—20 µm).