Additional contributions to the knowledge of predatory mites of the subfamily Coleoscirinae (Acari: Prostigmata: Cunaxidae) from the Philippines

Four new species of predatory mites belonging to the subfamily Coleoscirinae (family Cunaxidae) are described from the Philippines, namely, Neobonzia ermilovi n. sp., Neoscirula klompeni n. sp., N. lagunaensis n. sp. and N. lambatina n. sp. Keys based on females are provided for four species of Neobonzia, and 11 species of Neoscirula that are currently known from the Philippines. New locality and habitat data are given for four previously known species of the genera Coleoscirus and Neoscirula.


INTRODUCTION
The family Cunaxidae is one of the better-known groups of predatory mites in the Philippines. It includes 74 species described or recorded by , 1996, 2007, 2008, 2011, of which 26 belong to the subfamily Coleoscirinae. During a visit by Dr. Hans Klompen in January to early February 2016, samples of soil and litter mites collected primarily for uropodines yielded a number of new mites, including some unfamiliar cunaxids. These new collections were made in readily accessible sites where we had a collection per-mission. Surprisingly, relatively well-explored areas like Mt. Makiling and University of the Philippines Land Grant in the Laguna-Quezon border, new mite species are still showing up, indicating the rich diversity of mites in these relatively protected forested areas.
As of Den Heyer's (2011a) database for the family Cunaxidae, the Philippines ranked third (with 57 species) to South Africa (68 species) and USA (58 species). The Philippine records in named database, however, included only those reported by Corpuz-Raros et al. in 1995-1996, and failed to account for 17 other species recorded later by the same authors. Discovery of four new species described in this paper brings the total known Philippine cunaxid fauna to 78, probably now surpassing other countries worldwide. The objective of this paper is to describe one new species of Neobonzia and three of Neoscirula, both members of the subfamily Coleoscirinae. Secondary objectives are to update keys to Philippine species of both genera, and to record new localities and habitats for some previously known species of Coleoscirinae.

MATERIALS AND METHODS
Samples of litter, soil, and similar media were bagged in the field and subjected mainly to Berlese extraction in the laboratory. Most of the samples were decomposing material on the ground but litter lodged or hanging on branches of plants were also collected. Samples from ant nests hanging on trees were also taken, as well as soil samples from underground nests that were opened after trailing ant columns to their nest. Some litter samples were set up under no-light funnels in the field immediately after collection. Extracts with soil residues were floated using hydrocarbon flotation method with kerosene as the hydrocarbon agent. Extracts were preserved in absolute ethyl alcohol, and the mites separated from the rest of the arthropods contained in the samples. All mites were cleared in lactic acid, and those of interest were mounted on slides with Hoyer's as medium.
Mounted specimens were studied under a compound microscope model Zeiss Primostar. Illustrations were initially made with the aid of a drawing tube mounted on a Wild compound microscope but finer morphological details were drawn freehand after careful analysis of taxonomic characters. Measurements were made with an ocular micrometer and expressed in micrometers (µm) following a given part. Measurements of whole body parts like the entire body, gnathosoma, palps, chelicerae and legs, as well as dorsal idiosomal setae, were taken from most of the type specimens for a given species, and are expressed herein according to the following sequence: Holotype [range (mean, number of spec-imens measured)]. Measurements of other setae on gnathosoma and venter are those of the holotype.
Terms used for various structures follow those of Den Heyer (1981) except that the term hypognathum is replaced by the more widely used subcapitulum, and the term dt or dorsoterminal solenidion on the leg tarsi is renamed as dtsl as in Den Heyer et al. (2011). Nomenclature for dorsal body setae follows that of Kethley (1990), as adopted for the Bdelloidea by Den Heyer and Castro (2008a).
The chaetotaxy or number and types of setae on leg segments are given consecutively from legs I-II-III-IV for each segment. Schematic diagrams  showing setal types are provided, along with other key character states in Philippine species of Neobonzia and Neoscirula.
Diagnosis -This genus was redefined by Den Heyer (2011b) and this redefinition was adopted by Skvarla et al. (2014) and in the present paper. It includes species with 5-segmented palps that extend beyond the subcapitulum by at most the distal half of last segment. The dorsal basifemoral and telofemoral setae of palps are thin and simple but are both spine-like in N. gruezoi (Corpuz-Raros & Garcia, 1996) and the new species described herein. The palp tibiotarsus is long, basally stout and distally thin (S-shaped) as opposed to short and conelike in Neoscirula; may or may not have a tubercle, and the penultimate sts (simple tactile seta) on outer margin is rather long. There are 4 pairs of hypostomal setae, two pairs of adoral setae, and a cheliceral seta is usually present.
Neobonzia species are soft-bodied, with weakly sclerotized dorsal propodosomal shield and entirely membranous hysterosoma in females, while dorsal plates are more sclerotized and hysterosomal plates may be present in addition to the propodosomal in males. Extensive reticulated pattern is absent on the propodosomal shield but there may be lateral bands of subcuticular cells as in N. gruezoi and N. ermilovi n. sp. The hysterosoma bears setae c1-h1 and usually also c2 and f2. Coxal plates I+II are not fused medially as a sternal plate, coxal plates are usually not reticulated but some species may have a few subcuticular cells. The legs are usually shorter than idiosoma, never constricted apically as to end in lobes, and solenidia on tarsi are usually cylindrical, but basally or distally swollen in two Philippine species, N. gruezoi (as illustrated by Fuangarworn and Lekprayoon, 2004 based on specimens from Thailand) and N. ermilovi n. sp.

Male
Material -Holotype female, 1 male and 3 paratype females, Philippines, Luzon Island, Siniloan, Laguna-Real, Quezon border, University of the Philippines Land Grant, from dried fern litter hanging on roadside, 22 Jan. 2016 (R.C. Garcia, J.C.B. Naredo and H. Klompen); 1 female paratype same data as for holotype but from soil below rotten tree; 2 female and 1 male paratypes, also same data as for holotype but from soil in nest of army ant; and 2 male paratypes, same data as holotype but collected from an unknown habitat, 23 Jan. 2016. Type deposition -Holotype female, 6 paratype females and 2 paratype males are deposited in the Museum of Natural History, University of the Philippines Los Baños, College, Laguna, Philippines; and 2 paratype females and 1 paratype male in The Ohio State University Acarology (OSAL) Collection, Columbus, Ohio, USA.
Etymology -This species is dedicated to Dr. Sergey G. Ermilov, Tyumen State University, Russia, in recognition of his outstanding contributions to Philippine oribatology.
Diagnosis -Mites of the genus Neoscirula are relatively small, averaging 300 µm, lightly sclerotized and light brown with darker legs. The palps are short, stout, with thick and conical tibiotarsus, and end in a small claw which is usually undivided apically but sometimes has a subterminal tooth, giving it a bifid appearance. The subcapitulum bears 4 pairs of setae, the anteriormost (hg 1) longest and bent basally or "semi-geniculate", not truly geniculate as emphasized by Den Heyer and de Castro (2008b) against Smiley's (1992) first criterion for dividing the family Cunaxidae into subfamilies, and as basis for transferring Neoscirula to the subfamily Bonzinae where a truly geniculate hg1 is present. Adoral setae may be present or absent. Cheliceral setae may be present or absent.
Females have a weakly sclerotized dorsal propodosomal shield while the hysterosoma is entirely membranous, without dorsal shield. In the male, a hysterosomal shield is present in addition to the propodosomal. The propodosomal shield bears 2 pairs of trichobothria, vi and sce, and 2 pairs of sts, ve and sci. The hysterosoma bears 7 pairs of setae, c1-h1, c2 and h2, as well as f2 in some cases. Coxal plates I+II may be separate or fused medially as a sternal shield; coxal plates III+IV are contiguous and confined to the coxal bases. Dorsal and ventral shields are covered with fine or relatively coarser papillae and subcuticular cells may be additionally present. The legs are shorter than body, each ends in a pair of claws and rayed empodium, and the tarsus is not constricted apically as lobes. Solenidia of tarsi cylindrical, but one or two of them may be bulbous or basally swollen as in new Philippine species described in this paper.
Ventrally, coxal plates I+II contiguous, not fused medially as a sternal plate, finely papillate, with some 6 rounded subcuticular cells; III+IV also contiguous, with a few subcuticular cells. Six pairs of short sts on finely striate-papillate membrane between coxae II and genital plates. Genital plates rather small, with 2 subequal oval genital papillae and 4 pairs of subequally short (14)  tae. Paraanal setae present between genital and anal plates.
Type deposition -Both holotype and paratype females are deposited in the Museum of Natural History, University of the Philippines Los Baños, College, Laguna, Philippines.
Etymology -The specific name is coined from the Pilipino term, lambat, for net, referring to the reticulate pattern of dorsal shield and chelicerae.
Remarks -The female of N. lambatina most closely resembles the South African species, N. sevidi Den Heyer, 1980, in having distinct reticulations on propodosomal shield, spine-like setae on palp basifemur and telofemur, bifid palp tibiotarsal claw, and minute cheliceral seta. It differs from the named species by having a leg basifemoral chaetotaxy of 4-5-3-1 (vs. 3-4 or 5-3-1), presence of subcuticular cells on both coxal plates I+II and III+IV (vs. absent in both plates), and distinctly reticulate cheliceral trochanter and segment II (vs. randomly arranged papillae on trochanter, and forming irregular rows on segment II).
Distribution -Twenty-seven Neoscirula species have been described from all zoogeographical regions of the world, but the most records (12) come from the Oriental Region, 9 of which are from the Philippines alone (Skvarla et al., 2014). The addition of three new species in the present paper brings the known Philippine fauna to 12, the most diverse in the world, thus far.