A new species of Gaeolaelaps Evans and Till (Acari: Laelapidae) on Acinopus sp. (Coleoptera: Carabidae) from Iran

A new mite species of the genus Gaeolaelaps, Gaeolaelaps saboorii n. sp., collected from under the elytra and on the abdomen of Acinopus sp. (Coleoptera: Carabidae) in Iran, is described and illustrated.


INTRODUCTION
The mite family Laelapidae Berlese includes hundreds of species that are free-living predators in soil, as well as many others that have varying degrees of association with other animals, both vertebrates and invertebrates (Faraji and Halliday, 2009). Most Gaeolaelaps species were reported from soil-litter habitats, some others were collected from nests of vertebrates, from arthropods (or their nests), including mygalomorph spiders, millipedes, cockroaches, termites, mole crickets, cerambycid, passalid, carabid beetles and ants (Bregetova, 1977;Rosario, 1981;Tenorio, 1982;Karg, 1993;Strong and Halliday, 1994;Fain et al., 1995;Beaulieu, 2009). A large numbers of Gaeolaelaps species have been described in a loosely-defined genus Hypoaspis sens. lat.
Gaeolaelaps was considered at different taxonomic levels by some authors but we herein consider it as a separate genus (Beaulieu, 2009).
In Iran, only Gaeolaelaps nolli (Karg, 1962) was previously encountered on ground beetles (Nemati and Babaeian, 2010). It is probably that this record is accidental because G. nolli is typically known from soil and litter (Karg, 1962).
A large proportion of species identified or described as Hypoaspis appear to belong to Gaeolaelaps Evans and Till, 1966, as currently defined in previous publication (Karg, 1979;Tenorio, 1982;Beaulieu, 2009).
In the present work, one new species of Gaeolaelaps is described based on adult female and male taken from Acinopus sp. of the family Carabidae from northern Iran.

MATERIALS AND METHODS
Laelapidae phoretic on beetles were collected mainly in some regions of northern Iran over a period of two years. Beetles of the family Carabidae were collected using light traps, and then placed individually in vials of 70 % ethanol. Mites were removed from the beetles, cleared in Nesbitt's solution and mounted in Hoyer's medium. The nomenclature used for the dorsal idiosomal chaetotaxy is that of Lindquist and Evans (1965), the leg chaetotaxy is that of Evans (1963a), the palp chaetotaxy is that of Evans (1963b), and names of other anatomical structures mostly follow Evans and Till (1979). We use the term "lyrifissures" to refer to slitshaped sensilli (not true pores), and "pore" for circular or oval-shaped cuticular openings of unspecified function. Holotype and male paratype of the new species are deposited in the Acarological Collection, Department of Plant Protection, Yazd Branch, Islamic Azad University (YIAU). Two paratypes are also deposited in the Jalal Afshar Zoological Museum, College of Agriculture, University of Tehran, Iran (JAZM) and in the Australian National Insect Collection, CSIRO Ecosystem Sciences, Canberra, Australia (ANIC). All measurements in the descriptions are given in micrometres (µm).
Insemination structures -( Figure 1I). Laelapidtype sperm access system, tubulus long, wider at the solenostoma level of coxa III and entering sac-culus via a pair of circular openings. Sacculus an irregular, the proximal ends of the tubulus slightly swollen at junction with ramus.
Gnathosoma -Triangular epistome and subcapitular characters similar to female. Fixed digit with one blunt tooth, large distal hook and slender pilus dentilis. Movable digit of chelicera with one large tooth, spermatodactyl longer than movable digit, slightly tapered and with blunt tip, fringed hyaline arthrodial process at its base ( Figure 2D). Palpi with normal setation and similar to those of female.
Etymology -This species is named in honour of Prof. Alireza Saboori (Department of Plant Protection, University of Tehran, Iran), who devoted many years to teaching Acarology and training Acarologists in Iran.
Notes -This species is similar to G. blattae (Strong and Halliday, 1994) and G. concavus (Faraji and Halliday, 2009) in general appearance. The new species can be readily distinguished from them by following characters: peritreme shorter and extending to near the posterior level of coxa I only (longer and extending beyond anterior margin of coxa I in G. blattae), fixed digit in the female with four teeth (9-10 in G. blattae and 11 in G. concavus) and in the male with one blunt tooth large distal hook and slender pilus dentilis (as same as G. blattae and G. concavus), epistome triangular, projecting medially and almost smooth with a few denticles (rounded and denticulate in G. blattae and G. concavus), deutosternal groove with 6-10 denticles per row (12-17 in G. blattae and 16-20 in G. concavus), a smaller genital shield (more extensive and almost reaching anal shield in G. blattae and G. concavus), spermatodactyle longer, with narrower tip and bending apically as in Figure 2D (spermatodactyle shorter, with expanded tip and curved towards digit in G. blattae and G. concavus), femur II with av and pv1 slightly thickened (spine-like in G. blattae and G. concavus).
Remarks -Most Gaeolaelaps species described to date were collected from soil-litter habitats, whereas several ones were collected in association with arthropods. Most species that have been placed in Hypoaspis actually belong to Gaeolaelaps Evans & Till, 1966(reviewed by Beaulieu, 2009), because they lack long setae on the dorsal shield and on some leg segments (Joharchi and Halliday, 2011).
Gaeolaelaps saboorii n. sp. was collected under elytra and on the abdomen of the Acinopus sp.. This species morphologically similar to most other Gaeolaelaps species were collected from arthropods (or their nests). It is conceivable that most species associated with arthropods differ from the others in the genus by having concave posterior margin of sternal shield (deeply or slightly) and having triangular epistome with reduced denticulation and with apical point sometimes. It is possible that these mites are not parasites of beetles at all, but harmless feeders on exudates from the beetles' body (Costa, 1971), or predators that feed on other small invertebrates in the microhabitats created by the beetles (Joharchi and Halliday, 2011).