A new species of pterodectine feather mites (Acarina, Analgoidea, Proctophyllodidae) from the Little Spiderhunter Arachnothera longirostra (Passeriformes, Nectariniidae) in Meghalaya, India

Abstract The article describes a new species of the feather mite subfamily Pterodectinae from the Little Spiderhunter Arachnothera longirostra Temminck, 1826 (Passeriformes, Nectariniidae) in India. Pedanodectes angustilobus sp. n. differs from all known Pedanodectes species by having opisthosomal lobes short, at base wider than long, roughly rounded apically in males, and strongly elongated and narrowed lobar region with wide terminal appendages in females. A key to species of the genus Pedanodectes is presented.

In this paper, we describe a new species of Pedanodectes found on A. longirostra in India and we present a key for all species of this genus.

Materials and methods
The material used in the present paper was collected in Meghalaya (India), in January 2014. The birds were trapped by means of ornithological mist nets, identified and visually checked for the presence of mites and, after mites were collected, released back to the wild. Mite specimens were placed in tubes with 95% ethanol. Later, in the laboratory, the mite specimens were cleared in lactic acid and mounted on microscope slides in Hoyer's medium. Drawings were made using an Olympus CX21 microscope, using a camera lucida drawing device.
The bird specimens were identified according to Rasmussen and Anderton (2012) and Grimmett et al. (2011), and the taxonomy of the birds used in the present paper follows Clements et al. (2013). The description of new species is given according to the current format used for species of pterodectine mites (Mironov and Fain 2003, Valim and Hernandes 2006, Mironov 2006. The body chaetotaxy of mites follows that of Griffiths et al. (1990) with the modifications by Norton (1998) concerning coxal setae, and the chaetotaxy of legs follows Gaud and Atyeo (1996). The measuring techniques of particular structures used in the present paper were recently described by Mironov and Proctor (2009). We give the full set of measurements for the holotype (male) and a range of measurements for all corresponding paratypes. All measurements are in micrometers (μm). The holotype and all paratypes of the new species are deposited in the Acarological Collection of the "Grigore Antipa" National Museum of Natural History, Bucharest, Romania.
Legs I longer and thicker than legs II, femora II with ventro-basal crests, genua III with dorso-basal crest (Fig. 4A-C). Genual setae mGI and mGII noticeably thickened in basal half. Length of solenidia: ω1I [17][18] Etymology. The specific epithet refers to the narrowed lobar region of the female, and it is an adjective in the nominative singular.
Remarks. Pedanodectes angustilobus sp. n. clearly differs from all previously described Pedanodectes species because its males have well expressed opisthosomal lobes, and females have elongated and narrowed lobar region, with wide terminal appendages. Among previously known species of the genus, males of P. angustilobus sp. n. appear to be closest to that of P. mesocaulus (Gaud & Mouchet, 1957) from Deleornis fraseri cameroonensis (Bannerman, 1921) (Passeriformes: Nectariniidae). Males of both species have setae ps1 situated antero-lateral to the adanal suckers, epimerites I fused into Y, similar shape of opisthoventral shields and epimerites IVa with narrow anterior projections. Males of P. angustilobus sp. n. are easily to distinguish from those of P. mesocaulus by the following features: epimerites IVa have free the anterior projections and are connected posterior to the genital arch by a transversal sclerite, the tip of aedeagus does not extend beyond the posterior margin of idiosoma. In males of P. mesocaulus, the anterior projections of epimerites IVa are fused forming a pregenital sclerite while the transverse sclerite connecting the bases of these epimerites is absent, the tip of aedeagus extends beyond the posterior margin of idiosoma. Females of the new species are clearly different from those of the other species of the genus by the following unique combination of characters: the lobar region has the same width in anterior and posterior part; the terminal cleft is parallel-sided, with the margins almost touching, except for the anterior one third; and the terminal appendages are thick, their basal half is approximately as wide as opisthosomal lobes. In females of the other Pedanodectes species, the lobar region in the anterior part is wider than in the posterior part and the terminal appendages are narrower than lobes. The terminal cleft in females of the other species has the following shape: with the lateral margins parallel and almost touching in P. andrei and P. mesocaulus, with lateral margins sinuous and almost touching in certain parts in P. marginatus and P. latior; as a narrow inverted V in P. blaszaki, and as a narrow inverted U in P. hologaster.

Discussion
According to the diagnosis of the genus Pedanodectes, some authors considered that males of this genus practically have no opisthosomal lobes and setae ps3 are usually situated lateral or postero-lateral to the adanal suckers (Gaud and Atyeo 1996, Mironov 2008, Hernandes and Valim 2014. However in the original definition of this genus, Park and Atyeo (1971), apparently based on a some undescribed material they had on the hand, mentioned that the presence of weakly developed opisthosomal lobes and the position of setae ps3 antero-lateral to the adanal suckers can be found in some species. The new species found on A. longirostra in India and described in this paper demonstrates the example of a Pedanodectes species having distinct opisthosomal lobes and setae ps3 situated antero-lateral to the anal suckers in males.