Brevulacus extensus, Pye, Daniel R. L., 2012

Pye, Daniel R. L., 2012, New eriophyoid mites (Acari: Prostigmata: Eriophyoidea) in Britain: one new genus, four new species, 19 new records and two incursions, Zootaxa 3578, pp. 43-68 : 60-61

Brevulacus extensus n. sp.

( Figs. 13–15 )

FEMALE: (n=7). Body fusiform, 204 (184–234), 74 (74–78) wide. Gnathosoma 39 (37–59), projecting obliquely down, chelicerae 51 (38–58), setae d 5 (5–7), simple, setae ep 9 (9–11). Prodorsal shield 39 (39–44), 59 (53–59) wide, lobe anteriorly emarginate, ornamented with thick lines creating a net-like pattern: median line complete; admedian lines complete, curving outwards towards sc tubercles, then curving back just above sc tubercles to join the median line at the posterior; median and admedian joined at about 1/2 by two curved “U” shaped cross lines, and with a cross line at 90º at about 1/4; first submedian lines, anteriorly forming a “pincer” like shape on anterolateral margins of lobe, curving posteriorly down and outwards towards sc tubercles, and joining cross line at about 1/4 from rear; second and third submedian lines curving outwards from about 1/2 to outside margin of sc tubercles. In life, with white wax along lines on prodorsal shield. Tubercles sc extended, 22 (20–22), slightly ahead of rear shield margin, 29 (29–33) apart; setae sc 45 (43–48). Leg I 45 (38–45); femur 14 (13–14), seta bv I 20 (20–25); genu 8 (7–8), seta l ʺ 41 (35–41); tibia 15 (13–15), seta l ʹ 10 (9–10); tarsus 7 (7–9), seta ft ʹ 29 (28–30), seta ft ʺ 33 (31–36); seta u ʹ 8 (6–9); tarsal solenidion ω 11 (10–12); empodium simple, 12 (12–13), 11-rayed. Leg II 41 (35–43); femur 14 (13–15), seta bv 18 (18–21); genu 7 (6–8), seta l ʺ 13 (12–13); tibia 11 (10–13); tarsus 8 (8–9), seta ft ʹ 13 (10–15), seta ft ʺ 31 (30–32); seta u ʹ 7 (5–7); tarsal solenidion ω 13 (12–13); empodium simple, 12 (12–14), 11-rayed. Coxae 1 and 2 ornamented with few lines. Setae 1b 14 (10–15), 10 (10–12) apart; setae 1a 40 (28–41), 9 (9–16) apart; setae 2a 69 (43–69), 27 (26–33) apart; tubercles 1b and 1a 6 (6–7) apart; tubercles 1a and 2a 9 (9–13) apart. Coxigenital region with 15 (13–16) annuli. Opisthosoma with 37 (34–38) dorsal annuli, with a smooth medial line with microtubercles absent and not wax producing. Dorsal microtubercles triangular and acuminate, absent medially. In life, dorsal opisthosoma with two lateral white wax ridges; 63 (63–73) ventral annuli, ventral microtubercles small and beadlike, annuli completely microtuberculate. Setae c2 35 (23–35), on annulus 6 (6–9), 56 (55–63) apart; setae d 85 (40–87), on annulus 22 (18–26), 41 (38–51) apart; setae e 39 (37–63), on annulus 36 (34–41), 27 (26–30) apart; setae f 75 (32–75), on annulus 58 (58–68), 27 (23–30) apart, 5 (5–6) from rear. Setae h2 87 (68–103), 11 (11–12) apart; setae h1 4 (4–3), 8 (8–9) apart; h2 and h1 tubercles 3 (2–3) apart. Genital coverflap unornamented, smooth, 15 (13–16), 28 (27–31) wide. Setae 3a 56 (49–68), 20 (19–21) apart.

MALE: (n=2). Similar to female. Body fusiform, 173–198, 63–70 wide. Gnathosoma projecting obliquely down, 35–44, chelicerae 45–48, setae d 10, simple. Prodorsal shield 36, 42–48 wide, ornamentation same as female. Tubercles sc slightly ahead of rear shield margin, same as female, 17–18, 28–30 apart; setae sc 34–41. Leg I 40–41, femur 11–13, seta bv 18; genu 7, seta l ʺ 32–35; tibia 14, seta l ʹ 9–10; tarsus 7–8, seta ft ʹ 27–29, seta ft ʺ 25–31; seta u ʹ 6–7; tarsal solenidion ω 10–11; empodium simple, 11, 9-rayed on each side. Leg II 38, femur 12, seta bv 18–19; genu 6–7, seta l ʺ 9–11; tibia 11; tarsus 8, seta ft ʹ 8–12, seta ft ʺ 29–30; seta u ʹ 6–7; tarsal solenidion ω 11–12; empodium simple, 10–11, 9-rayed on each side. Coxae ornamented same as female. Setae 1b 12–13, 8–10 apart; setae 1a 30–32, 8–9 apart; setae 2a 56–62, 22–28 apart; tubercles 1b and 1a 6 apart; tubercles 1a and 2a 8–11 apart. Coxigenital region with 18 annuli. Opisthosoma with 36–37 dorsal annuli, 62–67 ventral annuli, microtubercles same as female. Setae c2 26, on annulus 4–5, 49–60 apart; setae d 56–73, on annulus 20–21, 38–44 apart; setae e 40–50, on annulus 31–34, 25–30 apart; setae f 38–40, on annulus 57–62, 24–27 apart, 6 from rear. Setae h2 62–97, 11 apart; setae h1 7, 7 apart; h2 and h1 tubercles 3 apart. Genital shield ornamented with fine granules, with short lines basally, 18–20, 21–25 wide. Setae 3a 31–53, 20–21 apart.

Host plant. Quercus robur L. ( Fagaceae ).

Relation to the host. Vagrant on the under surface of the leaves, causing no apparent damage.

Type locality. England, North Yorkshire, York, Strensall Common (54° 2ʹ 40.2ʺ N, 1° 0ʹ 41.76ʺ W), collected by C. Malumphy, 14.vii.2009.

Type material. Holotype female, on one slide, and two further paratype slides, each of one specimen, have been deposited at the Natural History Museum, London. Twenty one paratype slides, each of one specimen, have been retained in the collections of Fera.

Etymology. The specific name, extensus (masculine), relates to the elongate sc tubercles.

Discussion. This is the fourth species to be described in Brevulacus , the other three being: Brevulacus carpathicus Ripka 2011 , from Quercus petraea (Mattuschka) Liebl. (Fagaceae) , Hungary; Brevulacus jilinensis Xue, Song & Hong 2009 , from Quercus sp., China; and Brevulacus reticulatus Manson 1984 , from Quercus sp., New Zealand.

Differential diagnosis. Brevulacus extensus is most similar to B. carpathicus in the form and modification of the elongate scapular tubercles and the prodorsal shield ornamentation, but differs in the number of empodial rays (9-rays in B. carpathicus ), the smooth medial area on the dorsal opisthosoma (opisthosoma completely microtuberculate in B. carpathicus ), smooth genital coverflap (granules basally in B. carpathicus ), and also differences in the length of coxal setae 1b (28–41 in B. extensus , 14–21 in B. carpathicus ) and genital setae 3a (49–68 in B. extensus , 17–21 in B. carpathicus ).

Figures

FIGURE 13. Semi-schematic line drawings of Brevulacus extensus n. sp.: A. Lateral anterior region of female; B. Lateral annuli with microtubercles; C. Lateral posterior region of female; D. Full dorsal view; E. Leg I; F. Empodium; G. Coxigenital region of female; H. Internal female genitalia; I. External male genital shield. Scale bar: 50 µm for A, C & D; 25 µm for G, H & I; 17 µm for E; 12.5 µm for B; 10 µm for F.

FIGURE 14. Digital micrographs of Brevulacus extensus n. sp.: A. Dorsal anterior region of female; B. Coxigenital region of female. Scale bar 20 µm for both.

FIGURE 15. Digital micrographs of Brevulacus extensus n. sp.: A. Dorsal anterior region of male; B. Coxigenital region of male. Scale bar 20 µm for both.