Arrenurus bicuspidator Berlese, 1885

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 : 26

Arrenurus bicuspidator Berlese, 1885

( Fig. 12)

Arrenurus dubius Koenike, 1885

Arrenurus bituberusus Piersig, 1896

Arrenurus rugosus Protz, 1896

Material examined: 10 larvae deriving from 10 females.

Larvae relatively large; idiosoma 228–252 µm long.

Dorsum: Dp varies widely in size (DpL: 204–242 µm; DpW: 164–182 µm) and shield-shaped. Antero-lateral indents deep, almost right-angled, reaching to 1/5 and slightly above 1/4 of plate’s length and width, respectively. DpW/Mp1-Mp1 3.1. Lp2, Mh1 thicker than remaining ones and bipectinate. Mp1-Mp1 (54–58 µm) longer than Mp2-Mp2 (47–52 µm). Venter: CpIIm (34–38 µm), CpIIIm (35–38 µm) similar length, CpIm (66–70 µm) almost twice as long. C1, C2, C3 bipectinate; C4, Lh2, Lh3 pectinate. C1-CpIm (18–20 µm) 2/3 of C4-CpIIIm (30–33 µm). C1-C2 intermediate (45–46 µm). Expp pentagonal, its width almost equal to length. Exp in sub-central position on plate, slightly above E2. Palps: PIII 1 bipectinate; PIV1 relatively thin. Chelicerae: First segment cylindrical (71–73 µm), margins slightly curved. Legs: As long as body, LI< LII < LIII ( Fig. 3). Tarsi tapered distally. ITi8 thin, long, pectinate; ITa13, IITa13 long, pectinate. IFe2, IFe3, IGe3, ITi5, ITa7, ITa8, ITa9, ITa10, ITa12, IIFe2, IIFe3, IIGe3, IITi5, IITa7, IITa8, IITa9, IITa10, IITa12, IIIFe3, IIITi4, IIITa8, IIITa9, IIITa10, IIITa11, IIITa12, IIITa13, IIITa14 pectinate. IIITa13 located closer to proximal end of segment than IIITa14; IITi10, IIITi10 located near mid-point of tibia. IIITa8 present. Hosts: Coenagrion hastulatum (Charp.) , C. puella , C. pulchellum , Erythromma najas , Pyrrhosoma nymphula , Enallagma cyathigerum , Ischnura elegans (Vander L.) ( Davids 1997; Baker et al. 2006).