Two new species of Caligonellidae (Acari: Raphignathoidea) from Crimea

Female and larva of Caligonella quinqueocellata n. sp. and female, larva and protonymph of Molothrognathus tauricus n. sp. (Caligonellidae) are described from moss on the sandy soil from northern part of Crimea.


Introduction
The family Caligonellidae is a small group of predatory prostigmatid mites, which comprises 5 genera and about 60 species distributed almost worldwide, except Australia and Antarctica (Beron 2020). The caligonellid mites of Crimea are poorly studied. Previously only one species, Molothrognathus dilucidus Kuznetsov was described from Crimea (Kuznetsov 1978).
During the study of soil predatory mites, two new species, Caligonella quinqueocellata n. sp. and Molothrognathus tauricus n. sp. were collected from moss on the sandy soil in northern part of Crimea. Both species were collected from the same sample. The aim of this paper is to describe and illustrate these new species.

Material and methods
Mites were collected from the soil samples by Berlese funnels. Collected mites were mounted in Hoyer's medium. Notation applied to the body and leg setae follow that of Grandjean's system, overviewed by Kethley (1990) and Norton (1977) applied to Caligonellidae by Swift (2001); palpal setation follows Grandjean (1946). Mite morphology was studied using an AxioImager A2 compound microscope (Carl Zeiss, Germany) with phase-contrast and differential interference contrast (DIC) illumination. Photomicrographs were taken with an AxioCam ICc5 digital camera. All measurements are given in micrometers (μm) for holotype and available paratypes (in parentheses). For leg chaetotaxy, the number of solenidia is given in parentheses.
Differential diagnosis -The new species differs from all species of Caligonella in having five pairs of ocelli on prodorsum (only two in other species), The new species is most similar to Caligonella scutovata Smith-Meyer and Ueckermann described from South Africa (Smith- Meyer and Ueckermann 1989), by the presence of dorsal idiosomal shield and in having one pair of pseudanal setae. The new species differs from C. scutovata by the absence of ventral plate between coxae (present in C. scutovata) and location of setae ve on soft cuticle (ve located on dorsal shield in C. scutovata). Genus Molothrognathus Summers and Schlinger, 1955 Type species: Molothrognathus leptostylus Summers and Schlinger, 1955,
Larva (Figs 13, 14A Idiosomal venter (Fig. 13B) -Ventral idiosoma similar with that of protonymph, except absence of setae 2c, 3b and ag1. Lengths of ventral setae: 1a 25, 1b 26, 3a 35. Gnathosoma (Fig. 14A, B) -in general similar to that of female except following: subcapitulum without setae m (Fig. 14A), palptarsus with setae acm and sul simple (not eupathidia) (Fig. 14B). Length of stylophore 60, width 33, lengths of setae: or1 7, or2 8, length of palptarsal solenidion ω 3. Legs (Fig. 15) -Lengths of legs: I 165, II 125, III 145. Setation of legs as in larva of Caligonella quinqueocellata, except absence of seta p" on tarsus II. Leg I (Fig. 15A) longer than other legs. All leg setae smooth; setae (p) eupathid-like, blunt-tipped, other leg setae pointed; solenidion ω 7 digitiform, solenidia φ 3 and φp 6 baculiform. Leg II (Fig. 15B). All leg setae smooth and pointed; solenidion ω 5 digitiform. Leg III (Fig. 15C). All leg setae smooth and pointed.  Etymology -The name of the new species refers to its distribution in Crimea. Differential diagnosis -The female of the new species is most similar to Molothrognatus crucis Summers andSchlinger, 1955, described from USA (Summers andSchlinger 1955) and redescribed from Turkey (Doğan 2003), and M. mikaeeli Bagheri and Ahamazad, 2012, described from Iran (Ahanazad and Bagheri 2012), by the absence of setae ag3, and setae c2 subequal with c1 and ve and distinctly shorter than sce. The new species differs from M. mikaeeli by the presence of dorsal idiosomal shield (absent in M. mikaeeli). The new species differs from M. crucis in having dorsal idiosomal shield much shorter, its posterior margin not exceeding beyond bases of setae c1 and oval in shape (dorsal idiosomal shield very long, tongue-shaped, its posterior margin exceeding beyond bases of setae d in M. crucis) and by distinctly shorter setae sce, which about twice longer than c2 (sce much longer, about three times longer than c2 in M. crucis). The female of the new species is also similar to M. shirazicus Khanjani, Bakhshi andKhanjani, 2016, described from Iran (Khanjani et al. 2016) and M. colei Swift, 1996, described from Hawaii (Swift 1996, by the similar shape of dorsal idiosomal shield. The new species differs from both species by the absence of setae ag3 (present in M. shirazicus and M. colei). The new species differs from M. shirazicus in having setae c2 subequal with ve and sci (c2 distinctly longer than ve and sci in M. shirazicus). The new species differs from M. colei in having setae c2 twice shorter than sce (c2 and sce subequal in M. colei).

Discussion
The genera Caligonella and Molothrognathus are the most derived group of Caligonellidae (Fan 2000) and very similar morphologically. The only difference between genera is position of anterior end of peritremes. In Caligonella anterior end of peritremes situated anteroventrally and in Molothrognathus dorsomedially on stylophore. The discovery of larval stages of Caligonella quinqueocellata and Molothrognathus tauricus and description of their legs shows more derived leg setation in comparison to more primitive genus Coptocheles (Swift 2001). The only difference between larval legs setation in Caligonella quinqueocellata and Molothrognathus tauricus is the absence of seta p" on tarsus II in M. tauricus. The chaetotaxy of palptarsus in larval stage of Caligonellidae has never been described. In both described species, palptarsus of larva has the same number of setae as adults. However, setae acm and sul are not modified (not eupathid-like). In contrast to more early derivative genus Neognathus, Figure 15 Molothrognathus tauricus n. sp., larva: A-C -legs I-III respectively, dorsal aspect. palptarsus of Caligonella and Molothrognathus lacks seta lp.
The present research was supported by the Russian Science Foundation,