Silvestrichiloides berkarensis Kaplin, 2021

Kaplin, Vladimir & Shakula, Georgiy, 2021, New species of bristletails of the family Machilidae (Archaeognatha) from Kazakhstan, Acta Entomologica Musei Nationalis Pragae 61 (2), pp. 435-445 : 436-439

Silvestrichiloides berkarensis Kaplin , sp. nov.

( Figs 1 , 2 )

Type material. Hඈඅඈඍඒඉൾ: ♂ (slide-mounted, VIZR), KAZAKH- STAN: Zhambyl Region, Zhualy District, near Berkara, 42°53′30.5′′N, 70°36′44.5′′E, Maly Karatau Range, Berkarinski Complex Reserve, Gorge Berkara, 955 m a.s.l., under a dry tree on the ground near the stream, July 06, 2019, G. Shakula leg. Pൺඋൺඍඒඉൾඌ: 5 ♀♀ (1 ♀ on slide), the same locality, G. Shakula leg. ( VIZR).

Description. Body length: male 12.6 mm, female 11.6– 12.8 mm. Body width: male 3.5 mm, female 3.2–3.6 mm. Cercus length: male broken, female 6.0 mm. Total width of eyes: male 1.20 mm, female 1.13–1.15 mm. Eye length: male 0.54 mm, female 0.50–0.52 mm. Paired ocellus width and length: 0.29–0.30 mm and 0.16–0.17 mm, respectively, in both sexes. Coxal stylus length: male 0.8–0.9 mm, female 0.7–0.8 mm. Ovipositor length: 2.2–2.4 mm. Antennae slightly shorter than body. General body color whitish. Antennal base, frons, gena, occiput with brown pigment of weak intensity. Color of scales on upper and lower surfaces of body brownish or light brownish, respectively. Distal chains of flagellum divided into 12–14 annuli. Cercus of female approximately 0.52 body length.

Compound eyes dark with bluish tint (in alcohol). Ratio of length to width of compound eye about 0.90 in both sexes; ratio of contact line length to eye length about 0.40, in both sexes ( Fig. 1A ). Paired ocellus sublateral, ovoid, light brown with narrow white border, in male about 1.7 and in female 1.9 times as wide as long. Distance between inner margins of paired ocelli about 0.55 and between their outer margins 0.96 times total width of compound eyes, in both sexes. Frons between paired ocelli not especially convex.

Apical palpomere of maxillary palp in male about 0.90 and in female 0.82 times as long as preceding one. Their 5 th palpomere in male 1.0 and in female 1.2 times as long as 4 th palpomere. Dorsal surface of 7 th, 6 th and 5 th palpomeres of maxillary palp, respectively, with 11–12, 10–11 and 3 hyaline spines in male and 12–13, 13 and 5 spines in female ( Fig. 1B ). Ventral surface of 1 st –7 th palpomeres of male maxillary palp as well as dorsal surface of 1 st and 2 nd palpomeres of male labial palp with relatively numerous and long ciliary chaetae. Apical palpomere of labial palp triangularly oval, in male 0.82 and in female 1.20 times as long as wide ( Figs 1C, D ). Mandibles with four distal teeth in both sexes ( Fig. 1E ).

Fore femur of male and fore and middle femora of female widened. Ratio of length of 3 rd tarsomere to total length of hind tarsus 0.27–0.28 in male and 0.31–0.32 in female. Fore femur of male with opened, well developed sensory field, which includes numerous simple, relatively short sensilla connected to distal row of strong chaetae ( Fig. 1F ). Metric ratios concerning sensory field and femur as follows: LSF/WSF: 1.65, LSF/LF: 0.57, WSF/WF: 0.65, d/LF: 0.26, d/LSF: 0.45, d/WSF: 0.74. Under surface of tarsus, tibia and femur of male and female with two rows of pigmented spines, lacking in middle femur of male ( Fig. 1G , Table 1). Middle leg of male with numerous long chaetae. Ratios of length of styli to width of middle and hind coxae about 1.6 in male and 1.5 in female.

In both sexes, urocoxites I–VII with 1 + 1 eversible vesicles. Ratios of lengths of urostyli (without apical spines) and urocoxites II–VII 0.50–0.58, in both sexes; VIII 1.00 in male and 0.92 in female, IX 1.30 in male and 0.84 in female. Ratios of lengths of apical spines and urostyli II–VII 0.30–0.32, VIII about 0.25, IX 0.15–0.16, in both sexes. Posterior angle of urosternites II–VI 103°–106°, in both sexes. Urocoxites VII of female with protruding lobes between eversible vesicles. Ratio of length to width of one lobe about 0.90. Thoracic tergites, urotergites I– III, urosternites and urocoxites I–VIII without sublateral spines, in both sexes ( Fig. 2A ). Urocoxites IX with 9–10 + 9–10 inner sublateral hyaline spines in male and 6–9 + 6–9 ones in female. Number of sublateral hyaline spines on urotergites IV 3 + 3 in male and 4 + 4 in female; V 5 + 5 in male and 4–6 + 4–6 in female; VI 5 + 5, in both sexes; VII 6–8 + 6–8 in male and 5 + 5 in female; VIII 7–9 + 7–9 in male and 7 + 7 in female; IX 8–9 + 8–9 in male and 6–7 + 6–7 in female; X 3 + 3, in both sexes.

Male genitalia with parameres on urites VIII and IX. Parameres VIII with 1 + 3–4, IX with 1 + 6 divisions ( Fig. 2B ). Ratios of lengths of parameres VIII and IX 1.8. Parameres IX slightly surpassing apex of penis, clearly not attaining level of apex of urocoxites IX. Ratio of distance between apices of parameres of urocoxites IX to width of distal division of penis about 3.3. Basal division of penis about 1.2 times as long as its distal division.

Ovipositor sclerotized in distal part, thickened, almost completely covered by urocoxites IX, stout, typical of the genus Silvestrichiloides . Gonapophyses VIII and IX with 27 and 28 divisions, respectively ( Figs 2C, D ). Apical spines of gonapophyses as long as three distal divisions combined. Two or three distal divisions of anterior gonapophysis and three divisions of posterior gonapophysis with 4–5 and 7–8 large inner lateral fossorial teeth, respectively. The following 11–12 divisions of posterior gonapophysis with one inner and one outer lateral rows of large pigmented macrochaetae and fossorial spines, respectively. One basal division of anterior gonapophysis and 8–9 basal divisions of posterior gonapophysis glabrous. Distribution of chaetae on gonapophyses as shown in Figs 2C, D .

Differential diagnosis. Silvestrichiloides berkarensis sp. nov. differs from the other species of this genus in the number of annuli in the distal chains of the antennal flagellum, the structure of the apical palpomere of the labial palp, the number of ovipositor divisions, and the number of digging teeth on the posterior gonapophysis ( Table 2).

Etymology. The new species takes its name from the type locality, Berkara; adjective.

Habitat. Mountain shrub steppe.

Distribution. Kazakhstan (Zhambyl Region, Maly Karatau Range).

Genus Allopsontus Silvestri, 1911

Subgenus Kaplinilis Mendes, 1990

Kaplinilis Mendes, 1990: 28–29 . Type species: Machilanus bifarius Wygodzinsky, 1970 .

Figures

Fig. 1. Silvestrichiloides berkarensis sp. nov. (A–C, E–G – male, holotype; D – female, paratype): A – eyes and ocelli, front view; B – maxillary palp; C, D – labial palp; E – apex of mandible; F – fore femur; G – part of middle leg. Scale bar: 0.1 mm.

Fig. 2. Silvestrichiloides berkarensis sp. nov. (B – male, holotype; A, C, D – female, paratype):A – urocoxite VIII; B – urocoxite VIII (part) with parameres and urocoxite IX, with parameres and penis; C – anterior gonapophysis; D – posterior gonapophysis. Scale bar: 0.1 mm.