Description of a new species of Oodinychus (Acari: Uropodina: Trematuridae) from Egypt, with a key to the species

This paper reports on a collection of mites from the red palm weevil, Rhynchophorus ferrugineus (Oliver) (Coleoptera: Curculionidae) and its habitat in Ismailia governorate in Egypt. A new species Oodinychus egypticus n. sp. is described from adult females and males. This study continues work on possible biological control agents for the red palm weevil.


Introduction
Soil-dwelling mites of the suborder Uropodina are distributed all over the world, but they have not been adequately studied. They usually inhabit soil, debris, litter, manure, beach wrack, and the nests of mammals, birds and insects, (Karg 1989;Wiśniewski & Hirschmann 1993;Mašán & Krištofík 1995;Błoszyk 1999;Mašán 2001). Their maximal diversity is found in tropical rain forests (Lindquist et al. 2009). Recently a review of 300 genus-group names in this suborder was provided by Halliday (2015). Only 12 species of Uropodina have been reported from Egypt. Afifi (1980) described two new species in two genera, Zaher (1986) listed five species in five genera, El-Beshlawy & Allam (2007) described the new genus Aegyptus in the family Trachyuropodidae, Abd El-Ghani (2009) reported three species belonging to two genera of the families Trachyuropodidae and Uropodidae, and Hassan et al. (2011) listed four species from three genera. The genus Oodinychus was first reported for the Egyptian fauna by Hassan et al. (2011) and a new species in that genus is diagnosed here. A dichotomous key for the identification of the species of the genus is presented.

Materials and methods
Mites were collected from the red palm weevil, Rhynchophorus ferrugineus (Oliver) (Coleoptera: Curculionidae) and their habitats from Ismailia governorate. Mites were mounted in Hoyer's medium on glass slides for later examination, and descriptions were done using a phase contrast (Olympus, BHA) microscope. Mites were identified using the world taxonomic literature; illustrations were done with the help of an eye-piece attached to the phase contrast microscope and measured with the use of a graded ocular. Pores and lyrifissures on the idiosoma are in accordance with Athias-Henriot (1969) and Krantz & Redmond (1987), and generally follow the notation of Johnston & Moraza (1991). Notation of body setae is based on Lindquist & Evans (1965), with the modifications proposed by Lindquist (1994). Notation of the legs follows Evans (1963Evans ( , 1964Evans ( , 1972. Measurements are given in micrometres for each structure. Coordinates provided are approximate, as they were not taken at the time the samples were collected.
Genus Oodinychus Berlese, 1917 Urodinychus (Oodinychus) Berlese, 1917: 12. Oodinychus Halliday, 2015 Diagnosis -Idiosoma without long setae, surface of idiosoma covered by pits or reticulate sculptural pattern; inner margin of marginal shield crenulated; subcapitulum with laciniae pilose; only sc setae serrate; shape of hypostomal setae similar in both sexes; chelicerae with sclerotised node, with digits approximately equal in length; genital shield scutiform with process on its anterior margin; leg I with pretarsus and claws, genu I with a pair of ventral setae; adults and nymphs with peritremes.
Diagnosis -Dorsal shield with 36 pairs of aciculate setae and 16 pairs of pilose setae in female (35 and 22 pairs respectively in the male); idiosoma with small round pits; all ventral setae aciculate and smooth, except JV5, ZV4 and post-anal setae pilose (in addition to ZV3 in the male); tritosternum with a pair of lateral dentate basal loops, laciniae with dentate base, divided into three smooth laciniae, median lacinia longer than laterals in both sexes; genital shield with curved anterior sharp-tipped projection, almost reaching the base of coxa I; opisthogaster with seven pairs of opisthogastric setae (JV2, JV4, JV5, ZV1-ZV4) in female (eight pairs in males, JV1 present); anteromedian region of epistome convex, three-tined, the median tine longer with two lateral smooth denticles, and bifid median tine; fixed cheliceral digit with two teeth, movable digit with a tooth in both sexes; legs II-IV with thick and spine-like setae on telotarsus in both sexes.

Adult female (two specimens measured) (Figs 1-2)
Dorsum of idiosoma (Fig. 1A) -Dorsal shield oval, punctate and with small round pits, 533, 489 long and 402, 382 wide at widest level; with 36 pairs of aciculate setae, 16 pairs of pilose setae and a pair of lyrifissures (id1). Most dorsal shield setae of uniform length and shorter than distance to the subsequent seta, and associated with a pore. Marginal shield narrow, inner margin crenulated, ornamented with deep depressions anteriorly and with a row of irregular smooth structures posteriorly, clearly demarcated from dorsal shield, fused with dorsal shield anteriorly at level of z2; with six pairs of aciculate seate and six pairs of pilose setae, most of uniform length and associated with a pore. Lengths of recognised dorsal setae: j1 27, 25; j2 16, 14; z2 13, 10; J4 26; J5 29; Z5 21; S5 14, 12.
Venter of idiosoma (Figs 1B, C) -All setae aciculate and smooth, except JV5, ZV4 and post-anal setae pilose. Tritosternum base 10 long and 10 wide at mid-level, with a pair of lateral dentate basal loops, laciniae 42 long, with dentate base, divided to three smooth laciniae, median lacinia longer than laterals, free for about 63% of their total length (Fig. 1B). Sternal shield with anterior margin well delineated and dentate, medially convex, punctate, with four pairs of simple setae (st1-st4) and a pair of pores, st1 shortest, inserted anterior to genital shield, accompanied by a pair of lyrifissures iv1, st2-st4 lateral to genital shield, st2 close to st1, st3 accompanied by a pair of lyrifissures iv2. Endopodal plates between coxae I-II, II-III and III-IV fused to sternal shield. Genital shield tongue-shaped, punctate, 144, 143 long; with a long curved anterior sharp-tipped projection, 36 long, almost reaching the base of coxa I; posterior margin at level of coxae IV, straight, 66, 65 wide at posterior corners; shield located between coxae II-IV; genital seta st5 behind the shield; distance between genital setae 49, 42; paragenital lyrifissures (iv5) on unsclerotised cuticle posterolaterad of st5. Opisthogaster punctate and with small round pits, with seven pairs of opisthogastric setae (JV2, JV4, JV5, ZV1-ZV4) in addition to circumanal setae, eight pairs of pores and a pair of lyrifissures; anal opening small, 36, 35 long including frame. With 12 pairs of submarginal ventral setae, short and aciculate, most of uniform length and associated with a pore. Exopodal plates between coxae II-III and III-IV free from endopodal plates (Fig. 1C) 1C) -Peritrematic plate broadly fused with exopodal plate between coxae II-III; stigma located at level between coxae II-III, peritreme curved down anteriorly.
Type specimens -Holotype female, paratype female and five paratype males were collected from the red palm weevil, R. ferrugineus, October 2009 at Ismailia governorate (32°27′E, 30°58′N); deposited in the mite reference collection of Zoology and Agricultural Nematology Department, the Faculty of Agriculture, Cairo University, Giza governorate, all collected by R.A. Mahmoud.

Remarks -This new species is most similar to Oodinychus venezolanus
Dichotomous key for the separation of Oodinychus species based on adult females.
Oodinychus margaritaensis Sellnick, 1963 was not included in the following key because the original description of this species depended on only males.