Arrenurus robustus Koenike, 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 : 38

Arrenurus robustus Koenike, 1894

( Fig. 22 )

Material examined: 1 larva.

Dorsum: Dp (DpL: 202 µm; DpW: 166 µm) oval, widest in mid-length, posterior margin rounded. Anterolateral indents relatively large, obtuse-angled, about 1/5 and 1/4 of plate’s length and width, respectively. DpW/Mp1-Mp1 2.8. Lp2, Mh1 smooth and thin. Mp1-Mp1 about equal to Mp2-Mp2. Venter: CpIIm, CpIIIm very short, almost equal; CpI:CpII:CpIII ratio 3.8:1.1:1. All Cp setae smooth. C1-CpIm (15 µm) half of C4- CpIIIm (32 µm); C1-C2 (42 µm) intermediate. Expp oval in outline, much wider than long. Exp located below plate’s mid-point, below E2. Palps: PIII 1 smooth. Chelicerae: First segment bottle-shaped (88 µm), one margin slightly convex, other straight. Legs: Very short. IIITa8 present. IITi10 smooth, located near distal end of tibia; IIITa13 smooth. Hosts: Lestes sponsa , Pyrrhosoma nymphula , Enallagma cyathigerum , Platycnemis pennipes ( Davids 1997) .

Figures

FIGURE 22. Arrenurus robustus: A—ventral side, B—dorsal plate, C—excretory pore plate (scale bars: A, B—100 µm; C—20 µm).