Nothrholaspis Berlese, 1918

Emberson, Rowan M., 2010, A reappraisal of some basal lineages of the family Macrochelidae, with the description of a new genus (Acarina: Mesostigmata), Zootaxa 2501, pp. 37-53 : 47-48

Nothrholaspis Berlese, 1918

Macrocheles (Nothrholaspis) Berlese, 1918: 169 . Type species: Holostaspis tridentinus G. & R. Canestrini, 1882 (= Gamasus tardus Koch, 1841 ), by original designation.

Macrocheles (Scleritholaspis) Mašán, 2003: 80 . Type species: Gamasus carinatus Koch, 1839 , by original designation, new synonymy.

Macrocheles carinatus species group.— Hyatt & Emberson, 1988: 90.

Medium to large-sized (female dorsal shield 1000–1500 μm in length), heavily sclerotised, litter-dwelling Macrochelini; dorsal setae distally pilose, except for a group of more or less aciculate setae in central region of dorsal shield; three pairs of post-epigynal platelets free in membranous cuticle; males with separate sternogynal and ventri-anal shields; epistome with lateral processes fused basally; dorsal cheliceral seta pectinate laterodistally.

The dorsal shield has 28−29 pairs of setae, with J3 present in addition to J 2 in some species (e. g. N. montanus Willmann ). Most dorsal setae are pilose in their distal 1/2 to 2/3, but a group of more or less simple, aciculate setae are present in the central region of the dorsal shield. These include j6, z5, J2, and J3, if present; other setae including j2, j5, z1, s2, r3, r4, and J 5 may be simple in some species. The dorsal shield is generally ornamented with reticulate patterns and sometimes with punctate microsculpture, and the posterior and lateral margins are irregularly crenulate or smooth. The ventral shields have simple or pilose setae. The sternal shield has a reticulate-punctate pattern, which is more pronounced and more punctate in the posterior 1/3. The metasternal plates are small and oval, and bear the seta and pore. The epigynal shield is generally rounded posteriorly and has a punctate lineal pattern; the associated pores are free on the membrane. The ventri-anal shield is reduced, subtriangular or rounded, with three pairs of pre-anal setae, a punctate lineal pattern and para-anal extensions to the cribrum. There are three pairs of free post-epigynal platelets in the membranous cuticle. The epistomatic lateral processes are fused basally and the stem of the median process is strongly spiculate ( Fig. 16 ). Cheliceral dentition varies from species to species, and the cheliceral dorsal seta is pectinate laterodistally. Leg setation is normal for the family, with both simple and pilose setae. The spermathecal structures are mostly indistinct, but well developed infundibula and tubuli have been illustrated by Athias-Henriot (1968) for N. carinatus (Koch) and N. tardus (Koch) .

Males have separate sternogynal and ventri-anal shields. The spermatodactyl is short, about half the length of the movable chela; it is strongly tapered and directed posteriodorsally. Femur II is armed with a simple spur and the genu and tibia have small tubercles.

Notes. Nothrholaspis is distinguished from Macrocheles by the presence of three pairs of sclerotised postepigynal platelets in the membrane between the epigynal and ventri-anal shields, a feature shared with Macrholaspis and Geotrupacarus but rarely present in Macrocheles , as here restricted. Nothrholaspis is further distinguished from Macrocheles and from Macrholaspis by the distinctive shape of the epistome ( Fig.

16), and from Macrocheles by the pectinate cheliceral dorsal seta. Both the shape of the epistome and the cheliceral dorsal setae are similar to those seen in Geotrupacarus . The large size, pattern of pilose and aciculate dorsal setae, litter-dwelling habit, and regular occurrence of males are other characteristic, though non-defining, features of the genus.

Hyatt & Emberson (1988) found that the proportion of males in the four species occurring in the British Isles varied from 1.2% (1 out of 83 adults examined) in N. montanus to 37.3% (134 out of 359 adults examined) in N. submotus .

Nothrholaspis is a Palaearctic genus with species known from Britain and Ireland to China and Japan ( Hyatt & Emberson, 1988; Takaku, 1996; Ma & Liu 2003).

Included species: N. banaticus ( Iavorschi, 1977) , new combination; N. carinatus (Koch, 1839) ; N. caucasicus ( Bregetova & Koroleva, 1960) , new combination; N. coenosus ( Takaku, 1996) , new combination; N. montanus Willmann, 1951 ; N. shennongjianensis ( Ma & Liu, 2003) , new combination; N. subcoenosus ( Takaku, 1996) , new combination; N. submotus ( Falconer, 1924) , new combination; N. tardus (Koch, 1841)

Mašán (2003) proposed the synonymy of Macrocheles biharicus Iavorschi, 1977 and M. margaretae Iavorschi, 1977 with N. montanus Willmann, 1951 . His tentatively proposed synonymy of M. banaticus Iavorschi, 1977 with M. tardus (Koch, 1841) is less convincing because of distinct differences in the number and distribution of simple setae in the central region of the dorsal shield. In the absence of known original material of M. banaticus , this synonymy is not followed here.

Figures

FIGURES 12 – 17. 12 – 15. Reductholaspis analis (Hyatt & Emberson) comb. nov., female. 12. Chelicera; 13. Epistome; 14. Anal shield; 15. gnathosoma venter, showing position of hypostomal setae. 16. Nothrholaspis carinatus (Koch), epistome. 17. Macrholaspis opacus (Koch), epistome.