Gamasiphoides rykei, Halliday, R. B., 2005

Halliday, R. B., 2005, Predatory mites from crops and pastures in South Africa: potential natural enemies of redlegged earth mite Halotydeus destructor (Acari: Penthaleidae), Zootaxa 1079, pp. 11-64 : 45-47

Gamasiphoides rykei sp. nov. ( Figs 37–42 )

Specimens examined

Holotype female, Plettenberg Bay, site 30–13 (= 94­13), 18.viii.1994, roadside picnic area, T. K. Qin coll., clover and weeds. Paratypes, 1 female, same data as holotype; 3 females, Wilderness, picnic area, site 30­11 (= 94­11), 17.viii.1994, clover and Oxalis ; 1 female, Humansdorp, site 30–14 (= 94­13), 18.viii.1994, T. K. Qin coll., clover and weeds.

Description

Female

Dorsal idiosoma ( Fig. 37 ).Dorsal shield length 512–542 µm, width 294–319 µm (n=6), anterior half smooth, posterior half with polygonal ornamentation; with 34 pairs of smooth pointed setae, all subequal in length.

Ventral idiosoma ( Fig. 38 ). Tritosternum with bell­shaped base and heavily pilose laciniae, flanked by a pair of granular pre­sternal plates. Sternal shield with polygonal ornamentation throughout, with four pairs of smooth pointed setae and three pairs of pores. Epigynial shield trapezoidal, with indistinct ornamentation and a pair of smooth pointed setae, flanked by a pair of triangular endopodal plates. Ventri­anal shield heartshaped, slightly wider than long (length 294–365 µm, width 336–386 µm, n=6), not fused to dorsal shield, with polygonal ornamentation throughout, with seven pairs of smooth pointed setae and a postanal seta. Exopodal plates split at level of coxa III; peritrematal plates extending from level of seta j2 to stigmata between coxae III and IV, fused with broad exopodal plates level with coxa IV; peritreme short, extending to anterior margin of coxae III; unsclerotised integument with a pair of small circular platelets level with posterior margin of coxa IV, and a small irregularly­shaped post­anal plate.

Gnathosoma . Epistome with a prominent central point and a series of small lateral serrations at base of central point ( Fig. 39 ). Fixed digit of chelicera with two large proximal teeth, 4 smaller distal teeth and a pilus dentilis; movable digit with two large proximal teeth and a small distal tooth; arthrodial brush very short ( Fig. 40 ). Hypostomal groove with 7 rows of denticles, ca. 15 teeth per row; palp coxal seta, internal posterior hypostomal seta, external hypostomal seta, and anterior hypostomal seta subequal in length; corniculae short, heavy and robust; internal malae long and fine, external malae fringed ( Fig. 41 ); palp tarsal claw 3­tined; seta al 1 on palp genu bipectinate, seta al 2 spatulate ( Fig. 42 ).

Legs. Chaetotaxy: Leg I: coxa 0 0/1 0/1 0; trochanter 1 1/1 0/2 1; femur 2 3/1 2/3 2; genu 2 3/2 3/1 2; tibia 2 3/2 3/2 2. Leg II: coxa 0 0/1 0/1 0; trochanter 1 0/1 0/2 1; femur 2 3/1 2/2 1; genu 2 3/1 2/1 2; tibia 2 2/1 2/1 2; tarsus 3 3/2 3/2 3 + mv, md. Leg III: coxa 0 0/ 1 0/1 0; trochanter 1 0/1 0/2 1; femur 1 2/1 2/0 0; genu 2 2/1 2/0 1; tibia 2 1/1 2/1 1; tarsus 3 3/2 3/2 3 + mv, md. Leg IV: coxa 0 0/1 0/0 0; trochanter 1 0/1 0/2 1; femur 1 2/1 2/0 0; genu 2 2/0 3/1 1; tibia 2 1/1 3/1 2;; tarsus 3 3/2 3/2 3 + mv, md. All leg setae fine, smooth pointed, except av 1, av 2 on tibia IV, which are longer and thicker than surrounding setae. All tarsi with a pair of claws and a rounded membranous pulvillus projecting slightly beyond the claws.

Etymology. This species is named in honour of South African acarologist Dr P. A. J. Ryke.

Figures

FIGURES 37 – 42. Gamasiphoides rykei sp. nov., female. 37. dorsal idiosoma; 38. ventral idiosoma; 39. epistome; 40. chelicera; 41. hypostome; 42. palp genu. Scale bar = 100 µm for 37, 38, 50 µm for 40, 41. 42, 30 µm for 39.