Holoparasitus paralawrencei, Ilinca Juvara-Bals, 2017

Ilinca Juvara-Bals, 2017, New and rare species of Holoparasitus Oudemans, 1936 (Acari, Gamasida, Parasitidae) from the Athias-Henriot Collection, Revue suisse de Zoologie 124 (2), pp. 225-239 : 234-235

Holoparasitus paralawrencei sp. nov. Figs 5 , 6 A-D, F

Holotype: slide M753 in MHNG arthropoda collection; male; Spain, Prov. Pontevedra, road from Gondomar to Tui, Sierra Grova, near Bayona, leaf litter under Quercus sp.; 5.08.1956 (Sp. 485).

Paratypes: 4 males, 3 females; same data as for holotype.

Diagnosis: Male chelicera with fixed digit straight and toothless, movable digit with 1-2 tiny denticles. Female endogynium a big sack with two rounded, slightly denticulate formations ventrally, each of them continued dorsally by a long peculiar structure with denticles apically and 1 or 2 teeth medially.

Etymology: The species name refers to similarities between the new species and H. lawrencei .

Description of male: Length of dorsal idiosoma 720- 790, cuticle brownish red; podonotal setae: j1 = 42, others 36-42 long, opisthonotal setae shorter 12-18 long. Length of peritrematal shield 252-257.

Ventral idiosoma: Genital lamina with a trapezoidal central prong and rounded lateral corners. Sternogenital region reticulated, slightly raised between setae st1 and st2, with two conspicuous lines in its central part ( Fig. 6F ). Gland pore gv1 present, gland pore gv2 double. Length of sternal setae: st1 = 48, st2 = 50-54, st3 = 48, s t4 = 55; length of opisthogastric setae 36.

Gnathosoma: Gnathotectum trispinate, its central prong long and sharply pointed ( Fig. 5B ). Palptrochanter with simple seta v1 and pilose seta v2 ( Fig. 5C ). Corniculi conical. Hypognathal groove with 10 denticulate rows. Palpcoxal setae pilose (60 long), hypostomatic setae simple, their length 54-66. Incisions absent in cuticle behind hypostomatic setae. Chelicera ( Fig. 5A ): Fixed digit straight, pilus dentilis situated medially on a toothless inner margin. Movable digit with 1-2 small teeth. Arthrodial membrane with a small brush-like process.

Legs: Coxa II with a ridge of 7-10 denticles. Armature of legs II as in Fig. 5 D-E: rounded femoral apophysis and trapezoidal axillary process; ellipsoidal genual apophysis located near anterior margin of segment; large triangular medially apophysis situated on tibia, its length 42. Measurements: tarsus I = 192-206; tarsus IV = 216-233.

Description of female: Idiosoma 840 long, cuticle brownish-red well sclerotized. Length of peritrematal shield 266.

Ventral idiosoma: Presternal plate slightly denticulate. Sternal shield, reticulated, with a pair of lines passing under pores iv2 and joining in center of shield ( Fig. 6A ); gv1 situated below setae st3. Sternal setae simple, their length around 65, only st2 longer, 72-79. Paragynial shield with a small rounded postero-lateral protrusion; metagynial shield elongated. Epigynium reticulated, with mucronate apex and rectangular subapical structure with small rounded membranous wings ( Fig. 6 B-B’). Setae st5 simple, 66 long. Endogynium ( Fig. 6 C-D) a big sack, covered at its base with a fine, pleated cuticle, formed by 2 rounded and slightly denticulate protuberances located ventrally and by 2 elongated structures with denticles on their tips situated dorsally. Opisthogaster with 9 pairs of setae, their length around 50. Gland pore gv2 with one opening and 2 glands. Measurements: Distance between sternal setae: st1-st1’ = 66; st2-st2’ = 96-108; st3-st3 ’ = 122-132; epigynium: length = 168, basis = 233, h/b = 0.72.; tarsus I = 204; tarsus IV = 228-233.

Gnathosoma: Gnathotectum similar to that of male, trispinate with a longer central prong. Hypognathal groove with 9-10 fine denticulate rows. Length of hypognathal setae: hyp.1, hyp.2 = 50; hyp.3 = 24; pc. = 54. Chelicera with movable digit (120 long) with 3 denticles and fixed digit with 2 denticles above pilus dentilis and 2 denticles below it.

Remarks: The new species found in the north of Spain is very similar to H. lawrencei . Females of H. paralawrencei sp. nov. differ from those of H. lawrencei in the following characteristics: the structure of the endogynium, the anterior margin of the epigynium which has a mucronate apex and the proportion of this shield (h/b = 0.72 versus 0.84). The two noticeable lines on the sternal shield are joined in the middle in H. paralawrencei sp. nov. but not in H. lawrencei . The male of the new species has 1 or 2 small teeth on the movable digit of the chelicera which is without teeth in H. lawrencei . The size of the Spanish specimens is smaller than those of the British specimens.

Figures

Fig 5. Holoparasitus paralawrencei sp. nov., male. (A) Chelicera, antiaxial view. (B) Gnathotectum. (C) Palptrochanter. (D) Femur, genu and tibia of leg II, anterolateral view. (E) Genual and tibial apophysis, posterolateral view.

Fig 6. Holoparasitus paralawrencei sp. nov., female (A-D), male (F) and Holoparasitus lawrencei Hyatt, 1987, female (E). (A) Presternal plate and sternal shield. (B) Apex of epigynium and endogynium, ventral view. (B’) Apex of epigynium, dorsal view. (C-D) Endogynium, ventral and (E) dorsal view. (F) Sternal shield and genital lamina.