Arrenurus papillator (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 : 35

Arrenurus papillator (O. F. Müller, 1776)

( Fig. 19 )

Hydrachna papillator O. F. Müller, 1776

Trombidium papillator Fabricius, 1793

Atax papillator Fabricius, 1805

Hydrarachna abstergens Gistel, 1850

Anurania alegans Neuman, 1880

Material examined: 10 larvae deriving from 3 females.

Larvae small: idiosoma 174–191 µm long.

Dorsum: Dp small (DpL: 165–176 µm; DpW: 132–140 µm), oval; anterior and posterior margins rounded. Antero-lateral indents very large, about 1/3 of dorsal plate’s width and length, strongly obtuse-angled. DpW/ Mp1-Mp1 2.0. Lp2, Mh1 smooth and thin. Mp1-Mp1 long (67–71 µm), longer than Mp2-Mp2 (49–53 µm); Mp1-Lp2 very short (26–31 µm). Venter: CpIIIm smallest (22–24 µm), CpIIm slightly longer (25–29 µm), CpIm more than twice as long (51–53 µm). CpI:CpII:CpIII ratio 2.2:1.2:1. Setae on Cp smooth. C1, C4 located close to median margins of Cp. C1-CpIm (15–16 µm) slightly longer than 2/3 of C4-CpIIIm (19–23 µm); C1-C2 relatively short (34–40 µm). Expp pentagonal, sub-rhomboid in shape due to poorly differentiated upper angles. Expp width somewhat larger than length. Exp located about centrally on plate, level with E2. Palps: PV7 very large. Chelicerae: Relatively large; first segment short, thick (58–63 µm). Legs: Very short, distinctly shorter than body; LI< LII = LIII ( Fig. 4 ). Tarsi of all legs (particularly first pair) relatively stout, IIITa8 present. IITi10, IIITi10 smooth and situated close to distal ends of tibia; IIITa13 smooth. Hosts: Lestes barbarus (Fabr.) , L. dryas , L. sponsa , Coenagrion mercuriale (Charp.) , Ischnura elegans , Sympetrum flaveolum (L.), S. fonscolombii (Sél.) , S. meridionale (Sél.) , S. sanguineum (O. F. Müll.) , S. striolatum (Charp.) , S. vulgatum (L.) ( Davids 1997; Zawal & Dyatlova 2006).

Figures

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

FIGURE 19. Arrenurus pappillator: A—ventral side, B—dorsal plate, C—excretory pore plate, D—pedipalp, E— chelicera, F— leg I, G—leg II, H—leg III (scale bars: A, B—100 µm; C, D, F, G, H —40 µm; E—20 µm).