Gamasiphoides lootsi, 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 : 42-45

Gamasiphoides lootsi sp. nov. ( Figs 29–36 )

Specimens examined

Holotype female, Hermanus, 28.viii.1994, T. K. Qin, clover and weeds, site 30­31 (= 94­31). Paratypes, 1 female, same data as holotype; 4 females, 2 males, Humansdorp, 18.viii.1994, T. K. Qin, clover and weeds, site 30–14 (= 94­14); 8 females, 3 males, 42 km north of Cape Town, Kalbaskraal turnoff, 25.viii.1994, grass and vetch, site 30–30 (= 94­ 30).

Description

Female

Dorsal idiosoma ( Fig. 29 ). Dorsal shield length 722–781 µm, width 462–525 µm (n=13); oval shaped, surface smooth, with 37 pairs of smooth pointed setae visible dorsally; setae short, not long enough to reach the base of the next most posterior seta; arrangement of pairs slightly irregular in places.

Ventral idiosoma ( Fig. 30 ). Tritosternum with bell­shaped base and pilose laciniae. Pre­sternal area with two pairs of plates, the anterior pair smaller and irregularly shaped. Sternal shield with indistinct polygonal ornamentation anteriorly, posteriorly smooth; with four pairs of smooth pointed setae and three pairs of pores. Epigynial shield semi­circular, smooth, with one pair of smooth setae, flanked anteriorly by a pair of triangular endopodal plates, and posteriorly by a pair of oval­shaped metapodal plates each bearing a pore. Ventri­anal shield heart­shaped, approximately as wide as long (length 344–386 µm, width 353–378 µm), not fused to dorsal shield, with polygonal ornamentation medially, margins smooth, with 8 pairs of smooth pointed setae and a post­anal seta; para­anal setae inserted slightly anterior to anus. Exopodal plates split opposite coxa III; peritrematal plates extending from level of seta s1 to stigmata at a level between coxae III and IV, fused with broad exopodal plates behind coxae IV; dorsal shield encroaching onto ventral surface, with 2–3 pairs of setae not visible dorsally.

Gnathosoma . Epistome triangular, with a long medial point and two small lateral points, length of medial point 60 µm, width at base 80 µm ( Fig. 31 ). Fixed digit of chelicera with two small distal teeth, conspicuous pilus dentilis, two large triangular proximal teeth and a small basal tooth. Movable digit with a small distal tooth, a very large robust medial tooth, and two low proximal teeth, arthrodial brush very short ( Fig. 32 ). Hypostomal groove with 8 transverse rows of denticles, the posterior two of which extend well outside the groove. Palp coxal seta, internal and external posterior hypostomal setae and anterior hypostomal seta subequal in length (ca. 45 µm); corniculae very short, heavy, and robust; internal malae long and fine, external malae fringed, salivary styli conspicuous ( Fig. 33 ). Palp tarsal claw 2­tined, seta al 2 on palp genu spatulate, other palp setae smooth and pointed.

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. All tarsi with a pair of claws and a rounded membranous pulvillus projecting slightly beyond the claws.

Male

Dorsal idiosoma. Dorsal shield length 676–727 µm, width 412–458 µm (n=5), structure and chaetotaxy as for female.

Ventral idiosoma ( Fig. 34 ). As for female, except sternal and epigynial shields fused to form a sterniti­genital shield, with five pairs of setae and three pairs of pores, large genital aperture at anterior margin of shield.

Gnathosoma . As for female except fixed digit of chelicera with a small distal tooth, a small tooth adjacent to the pilus dentilis, and three large proximal teeth; movable digit with a single medial tooth, spermatodactyl fused with movable digit for most of its length, with a robust distal projection extending slightly beyond the tip of the movable digit, arthrodial brush modified into a membranous flap ( Fig. 35 ).

Legs. As for female, except femur II with a prominent ventral spur, genu II with a smaller capitate spur, and tibia II with a short thick spur­like seta ( Fig. 36 ).

Notes

In the key to species of Gamasiphoides given by Karg (1993b), G. lootsi runs to G. octosetae Karg 1976 , on the basis of the shape of the ventri­anal shield (length = width), short dorsal shield setae, shape of the epistome, and the presence of 8 pairs of setae on the ventri­anal shield. However, G. l o o t s i differs from G. o c t o s e t a e in having sternal shield setae st1 and st2 smooth and pointed (pilose in G. o c t o s e t a e). The leg chaetotaxy of G. lootsi agrees with that for African species of Gamasiphoides described by Lee (1970).

Etymology

This species is named in honour of South African acarologist Dr G. C. Loots.

Figures

FIGURES 29 – 33. Gamasiphoides lootsi sp. nov., female. 29. dorsal idiosoma; 30. ventral idiosoma; 31. epistome; 32. chelicera; 33. hypostome. Scale bar = 100 µm for 29, 30, 60 µm for 31, 32, 33.

FIGURES 34 – 36. Gamasiphoides lootsi sp. nov., male. 34. sterniti­genital shield; 35. chelicera; 36. femur, genu, and tibia of leg II. Scale bar = 100 µm for 34, 80 µm for 35, 36.