Redescription of three species of phytoseiid mites (Acari, Mesostigmata) from Poland

Three species of phytoseiid mites of the genera Amblyseius and Typhlodromus (Parasitiformes, Phytoseiidae) are found for the first time in fauna of Poland. More detailed redescriptions, drawings, measurements, and diagnosis of the species, A. krantzi (Chant, 1959), A. rademacheri (Dosse, 1958) and T. pritchardi Arutunjan, 1971 as well as the data of mite locations in Poland are given.


INTRODUCTION
Phytoseiid mites are well known as effective predators of small microarthropods, particularly phytophagous pests on various plants in terraneous plant associations. Occasionally, the plantinhabiting phytoseiid mites can be found in other habitats such as moss, herbal rhizosphere, soil, and so on (Kolodochka, 2006). During the present study on mites inhabiting soil and litter in the Polish National Parks, some phytoseiid species new for Polish fauna were found. These species, namely Amblyseius krantzi (Chant, 1959), A. rademacheri (Dosse, 1958), and Typhlodromus pritchardi Arutunjan, 1971 were not included earlier in the Checklist of Animals of Poland (Razowski, 1997).
The aim of this paper is to record three phytoseiid species for Poland and to provide more detailed descriptions.

MATERIALS AND METHODS
Specimens of phytoseiid mites (Parasitiformes, Phytoseiidae) were extracted using a Berlese funnel from samples of soil, litter and moss collected in three Polish National Parks in 2010-2013. The mites were kept in 70 % alcohol, and then mounted on microscope slides in Hoyer's medium for examining under Zeiss Axioscop 2 and MBI-3 (LOMO) microscopes. A phase contrast attachment KF-1 (LOMO) and a camera Lucida apparatus were used for the drawings. The nomenclature of dorsal and ventral setae follows that of Chant and Mc-Murtry (2007), dorsal solenostomes Athias-Henriot (1975), spermathecal structures Wainstein (1973) and Kolodochka (1990). The apical tooth is not included in the number of teeth of the cheliceral digits. Measurements are presented in micrometers (µm).
For the most recent distribution records of these species see the website of "Phytoseiidae Database" (Demite et al., 2015).
Males were absent in investigated material.
Notes -The absence of ventral setae ZV3 in A. krantzi is a unique feature which clearly separate it from the other closely related species. Amblyseius krantzi resembles A. rademacheri (Dosse, 1958) and A. andersoni (Chant, 1957) by having dorsal setae s4, Z4, Z5 distinctly longer than others, j1 and j3 medium, the rest of dorsal setae very short; and large anal pores.
broader than genital shield, and anal pores inclined and not closely associated and slightly posterior to level of setae JV2 bases), by atrium of spermatheca with short neck (in A. rademacheri atrium sedentary) and by presence of 3 teeth on movable cheliceral digit (instead of 2 as in A. rademacheri).
Amblyseius krantzi distinctly differs from A. andersoni by dorsal shield without constrictions at level setae R1, by large oval anal pores associated with setae JV2 instead of in A. andersoni dorsal shield with constrictions, and fissured anal pores not associated with preanal setae.

Amblyseius rademacheri
Notes -Features which distinguish A. rademacheri from A. krantzi were given in notes for A. krantzi. Females of A. rademacheri may be differentiated from similar A. andersoni by dorsal shield distinctly reticulated, presence of 2 teeth on moveable digit of chelicerae, and dorsal setae Z4 and Z5 roughly serrate and thick, as against in A. andersoni dorsal shield smooth, moveable digit of chelicerae with 3 teeth, and dorsal setae Z4 and Z5 slightly serrate and thin.
Notes -Typhlodromus pritchardi was first described from strawberry (Fragaria sp.), 800 m a.s.l., Ijevan District, Armenia. Chant and Yoshida-Shaul (1987) gave T. pritchardi the status of species inquirenda in a world review of the "pyri species" group in the genus Typhlodromus Scheuten. These authors were unable to examine the holotype and proposed T. andrei Karg, 1982 as a possible synonym of the T. pritchardi because of its close resemblance. Revising the genus Typhlodromus, Denmark (1992) redescribed T. pritchardi adequately but established 4 teeth on fixed digit of chelicera whereas Arutunjan (1971) specified 3 teeth. Also he didn't support Chant's and Yoshida-Shaul's opinion (1987) about about close resemblance of T. pritchardi and T. andrei Karg when noted: "The spermathecae are distinct in the two species ...". Faraji et al. (2012) compared descriptions of these two species, found some differences, and identified the Iranian specimen as T. pritchardi.
After Denmark's revision, T. pritchardi was redescribed twice. But neither of these descriptions corresponds to that of Arutunjan (1971) in details. Re-description of T. pritchardi by Faraji et al. (2012) includes the following difference: "dorsal setae smooth, except for Z5, slightly serrate". On the contrary, seta Z5 smooth in original description and in the Polish specimens.
Posterior dorsal setae (Z4, Z5, S2, and S4) in figure of T. pritchardi in Papadoulis et al. (2009) are shown shorter, and atrium of spermatheca sedentary (neck absent), but setae Z5 smooth, fixed digit of chelicera with 3 teeth, and leg IV with three macrosetae as in original description.
Usually, some of morphological differences (especially metric data) may occur as a result of variability of specimens collected from different geographical distributions. But other distinctions may indicate deeper dissimilarity and testify of an interspecies distance. Thus, additional revision of discussed specimens would be useful to reach a final conclusion.
Typhlodromus pritchardi is a rare and not numerous species. As a rule, it inhabits coniferous plants but from time to time solitary specimens were found on herbs and mosses in Armenia, Iran, Greece, Russia (Moscow Province, Yaroslavl Province), and Ukraine (Demite et al., 2015).