Pachygnathus nasutus, Uusitalo & Ueckermann & Theron, 2020

Uusitalo, Matti, Ueckermann, Edward A. & Theron, Pieter D., 2020, A review of the family Alycidae (Acari, Acariformes) from South Africa, Zootaxa 4858 (3), pp. 301-340 : 305-311

Pachygnathus nasutus sp. nov.

( Figs. 16–28 )

Description. Dorsum ( Figs. 16, 17 ). Length 400–420 μm; holotrichous number of setae per segment dorsally, ad- ditional setae of small size on ventral side, soft integument slightly undulating; sclerotic crista from naso to sensillar area, microplates of setae vi inseparably linked to crista, setae exp small, barbed, medial to anterior pair of lateral eye spots.

Venter ( Fig. 21 ). Genital valves each with 13–15 genital setae per valve; 4 anal setae per valve.

Gnathosoma ( Figs. 18–20 ). Chelicera beak-like with a few minute teeth on both chelae, and without cheliceral setae; subcapitulum with three pairs of setae and one pair of smooth adoral setae; four sparsely barbed palpal eupathids, clearly separate from each other.

Legs ( Fig 22 ). Solenidial formula for tarsi, tibiae, genua and femora on legs I, II, III and IV, respectively: 2- 1-0-0, 2-2-2-0, 3\4-2-2-2, 3-0-0-0, solenidion ω2 well moved anteriorly from adaxial end of lyrifissure, famulus I peg-like distally, famulus II a tiny rod abaxially.

Larva (n=1, Figs. 27, 28 )

Dorsum. Length 180 μm, holotrichous, sensillae ve and sci slightly swollen, setae longest on caudal segments.

Venter. Genital area absent, 3–4 anal setae per valve.

Gnathosoma . 1 pair of palpal eupathids.

Legs. Empodia clawless, solenidial formula for tarsi, tibiae, genua and femora on legs I, II and III, respectively: 1-1-0, 2-2-2, 3-2-2, 1-0-0.

Other life stages:

Protonymph (n=3, Figs. 25, 26 ), 1 genital seta per valve, subcapitulum with 2 pairs of setae and one pair of adoral setae.

Deutonymph (n=4; Fig. 24 ), 5 genital setae per valve.

Adult male (n=5; Fig. 23 ), 13−15 genital setae per valve, 10 pairs of eugenitals.

Adult female (n=7; Fig. 21 ), 13−15 genital setae per valve, 1 pair of eugenital setae.

Type material. Holotype female, 6 paratype females, 5 paratype males, 4 paratype deutonymphs, 3 paratype protonymphs and 1 paratype larva, from soil under Maytenus cymosa (Celastraceae) , vicinity of Potchefstroom, NORTH-WEST PROVINCE, 13 April 1972, J.A. van Huyssteen. Deposited at ARC-Plant Health and Protection, Pretoria, South Africa.

Differential diagnosis. This species can easily be differentiated from the neotrichous species of the genus by having a holotrichous dorsum in all stages ( Fig. 27 ), and femora I with 3 solenidia (instead of 2 or 5–7).

Etymology. The species name refers to the prominent naso.

Figures

FIGURES 16−22. Pachygnathus nasutus sp. nov. 16—Prodorsum, sclerotized crista, filamentous sensilla ve and sci ciliated, setae exp small; 17—Swollen naso; 18—Beak-like chelicerae, typical to genus; 19—Palp tarsus with 4 pseudacanthoid eupathids; 20—Subcapitulum, 1 pair of adoral setae; 21—Genital valve of female, 13 genital setae, 2 eugenital setae; 22—Tarsus I (2 solenidia), famulus I (arrow), Tibia I (2 solenidia).

FIGURES 23−28. Pachygnathus nasutus sp. nov. 23—Genital valve of male, 15 genital setae per valve, 10 pairs of eugenitals; 24—Deutonymph, genital area, 5 genital setae per valve; 25—Protonymph, genital area, 1 genital seta per valve; 26—Protonymph, subcapitulum; 27—Dorsal habitus of larva, holotrichy, sensilla ve and sci slightly swollen, 1 pair of palpal eupathids; 28—Ventral habitus of larva, genital area absent, 3–4 anal setae per valve. 16−28 from RSA, near Potchefstroom.