Lasioseius lacunosus Westerboer, 1963

Mašán, Peter, 2023, On some blattisociid mites (Acari: Mesostigmata: Lasioseius, Cheiroseius) from Slovakia, with notes on the genus Hyattella sensu Krantz, 1962, Zootaxa 5361 (2), pp. 159-180 : 168

Lasioseius lacunosus Westerboer, 1963

( Figs 16‒23, 25 , 30, 31 )

Lasioseius (Lasioseius) lacunosus Westerboer, 1963: 238 .

Lasioseius lacunosus .— Karg, 1971: 248; 1993: 249; Treat, 1975: 121; Farrier & Hennessey, 1993: 36; Gwiazdowicz et al., 2008: 36; Çakmak et al., 2011: 583; Moraes et al., 2016: 173 .

Lasioseius (Crinidens) lacunosus .— Karg, 1980: 349; Christian & Karg, 2006: 156.

Material examined

One female, three males: SW Slovakia, Little Carpathians Mts., Bratislava Capital, Záhorská Bystrica Settlement, Kačín Forest , elevation 335 m, decidouous forest, in bark crevices of a maple ( Acer sp. ) soaked with xylem sap , 27 June 2019 (leg. author). All specimens were deposited in the Institute of Zoology of the Slovak Academy of Sciences, Bratislava , Slovakia.

Taxonomic notes

This is the first record of L. lacunosus for Slovakia. Some specific morphological structures of a female from Slovakia, which are important for verifying its identity, can be seen on the micrographs ( Figs 16, 17 , 20 , 23, 25 , 31 ). I also examined a fairly well preserved female, clearly conspecific with the female from Slovakia, on a slide deposited in the Bavarian State Collection of Zoology in Munich and labeled ʻ Lasioseius lacunosus n. sp. ʼ (No. W34/14). Unfortunately, this available specimen (slide) does not bear a type designation or specific collection data, but according to Gwiazdowicz et al. (2008) it belongs to the original series of Westerboer.

As also noted in the taxonomic notes on the new species above, L. lacunosus has specially modified macrosetae on the tarsi II‒IV, and this fact was not illustrated or mentioned in the original description by Westerboer (1963). Similar to the legs, the males have not been described before, so I include the following description of some of the most important morphological structures:

Description (Male) ‒ ( Figs 18, 19, 21, 22 , 30 )

Dorsal shield 500‒555 long, shorter than legs IV (525‒575), with coarse reticulate pattern and setae similar to those of female; all anteromarginal setae (r2‒r6) on dorsal shield, but all posteromarginal setae (R1‒R6) on soft cuticle adjacent to shield margin; UR setae of submarginal cuticle completely reduced, absent (four pairs in female); opisthogastric region normally with six pairs of pre-anal setae on ventrianal shield (JV1‒JV3, JV5, ZV1, ZV2, and asymmetrically sometimes ZV4) and two pairs on soft cuticle (ZV4 and ZV5), but setae JV4 and ZV3 absent (present in female); chelicerae with elongate middle article, fixed digit with one small subapical tooth and a row of five teeth, movable digit with one distal tooth and an intricately formed spermatodactyl, with club-shaped proximal and medial parts and mushroom-shaped distal part ( Fig. 18 ); epistome as in female ( Fig. 19 ); legs II slightly thickened and stouter than the others, and partially armed ‒ some anteroventral setae, namely av on femur II ( Fig. 21 ) and av2 on tarsus II ( Fig. 22 ), modified into a stout spur.

Figures

FIGURES 15–17. Lasioseius spp., females. 15. L. cheiroseioides sp. nov., sperm-reception structures, lateral view; 16. L. lacunosus, dorsal idiosoma; 17. L. lacunosus, ventral gnathosoma. Scale bars: 25 µm (Fig. 17), 50 µm (Fig. 15), 100 µm (Fig. 16).

FIGURE 18–22. Lasioseius lacunosus. 18. Chelicera (male), lateral view; 19. Epistome (male); 20. Chelicera (female), lateral view; 21. Femur II (male), ventral view; 22. Tarsus II (male), ventral view. Scale bars: 25 µm (Figs 18‒20), 50 µm (Figs 21, 22).

FIGURES 23–26. Lasioseius spp., females. 23. L. lacunosus, ventral shields; 24. L. cheiroseioides sp. nov., dorsal shield sculpture of hexagonal area; 25. L. lacunosus, dorsal shield sculpture of hexagonal area; 26. L. epicrioides, dorsal shield sculpture of posteromedial area. Scale bars: 50 µm (Fig. 23), 25 µm (Figs 24‒26).

FIGURES 27–31. Lasioseius spp., dorsoventral habitus. 27. L. cheiroseioides sp. nov. (female); 28. L. epicrioides (female); 29. L. diffindatus (female); 30. L. lacunosus (male); 31. L. lacunosus (female). Scale bar: 300 µm.