Morphological characteristics of water mite larvae of the genus Arrenurus Dugès, 1834, with notes on the phylogeny of the genus and an identification key Author Zawal, Andrzej text Zootaxa 2008 2008-05-07 1765 1 1 75 https://biotaxa.org/Zootaxa/article/view/zootaxa.1765.1.1 journal article 10.11646/zootaxa.1765.1.1 1175­5334 5123752 Arrenurus bisulcicodulus Piersig, 1892 ( Fig. 43 ) Material examined: 10 larvae deriving from 10 females . Larvae relatively large: idiosoma 220–230 µm long. Dorsum : Dp egg-shaped (DpL: 220–224 µm ; DpW: 168–174 µm ), widest at mid-point, slightly rounded proximal and strongly rounded distal margins. Antero-lateral indents intermediate in depth, slightly obtuseangled, extending to 1/6 and 1/4 of plate’s length and width, respectively. DpW/Mp1-Mp1 equals 3.8. Lp2, Mh1 smooth. Mp1-Mp1 intermediate ( 44–46 µm ), equal length to Mp2-Mp2 ( 43–48 µm ); Mp1-Lp2 intermediate ( 38–43 µm ). Venter : CpI, CpII, CpIII measure 62–67, 31–32, 38– 42 µm , respectively, their ratio being 2.1:1:1.3. Setae on Cp smooth. C1-CpIm ( 20–22 µm ) about 2/3 of C4-CpIIIm ( 30–31 µm ). C1-C2 intermediate ( 42–45 µm ). Expp oval, its width almost equal to its length. Exp located below plate’s mid-point and below E2. Palps : PIII 1 smooth; PV5 pectinate. Chelicerae : First segment long ( 80–86 µm ), bent cylindershaped, distinctly narrowing in distal part. Legs : Somewhat shorter than body; LI< LII < LIII ( Fig. 3 ). ITi8 thin, short; IITi10, IIITi10 smooth, short, situated at about 2/3 of distance to distal end of tibia. IIITa8 present. Hosts : Nematocera ( Münchberg 1938 ).