Lanceacheyla whartoni Xia, Klompen and Childers

Xia, Bin, Klompen, Hans & Childers, Carl C., 2011, A new genus and species of Cheyletidae (Acariformes: Prostigmata) from citrus trees in Florida, Zootaxa 2796, pp. 29-36 : 30-34

Lanceacheyla whartoni Xia, Klompen and Childers , sp. n.

( Figs. 1 –12)

Diagnosis. As for genus.

Description. Female (N=5) ( Figs. 1–8 ). Body length (including gnathosoma ) 401 (390; 378–401), maximum width 253 (230; 207–253).

Gnathosoma ( Fig. 3 ). Length 135 (136; 130–141), width 117 (117; 111–120). Rostrum broadly conical, with two pairs of apical (ao1, ao2) and one pair of ventral (n) setae. Rostral shield with granular surface. Peritremes arched, with 6–7 pairs of links. Palp femur length 52 (52; 49–55), width 62 (61; 57–64); with three setae, one lanceolate dorsal (d) 57 (51; 48–57) and two smooth and filiform ventral (l’, v). Palp genu with one lanceolate dorsal (d) [38 (38; 36–38)], and one filiform ventral (l”) seta. Palp tibia with three filiform setae (d, l’, l”). Palp tibial claw with 5–6 teeth. Palp tarsus wider than long, bearing 2 comb-like (acm, sul) and 2 sickle-like (ul’, ul”) setae; seta acm with about 12 teeth, sul with about 17.

Idiosoma ( Figs 1, 2, 4 ). Length 301 (296; 282–310). Dorsum largely covered by two well-sclerotized shields. Anterior dorsal shield length 122 (122; 117–129), maximum width 211 (200; 188–211); posterior dorsal shield with a straight anterior margin, abutting anterior shield; length 132 (137; 132–147) and width 199 (193; 179–199). Eyes absent. All dorsal shield setae squamiform. Anterior shield with 12 pairs of setae: 4 pairs of anterior-lateral setae, vi, ve, sci, and sce (length 33–41, width 8–12), and 8 pairs of “ c ” setae (length 25–28, width 8–10). Humeral setae (c2) situated off anterior shield, lanceolate, length 69 (71; 66–75); almost twice as long as anterior-lateral setae. Posterior shield with 9 pairs of setae (d1, d2, e1, e2, f1, f2, h1, h2, h3), slightly shorter than those on the anterior shield. Interscutal membrane striate, without additional ornamentation. Venter: without shields. Coxal field I–IV with, respectively, three (1a, 1b, 1c), one (2b), three (3a, 3b, 3c), and three (4a, 4b, 4c) setae. Genital and anal region adjoining. Anal region with three pairs of ps setae, genital area with two pairs of genital (g) setae; three pairs of aggenital (ag) setae anterior to the genital region. All ventral setae smooth, filiform.

Legs ( Figs 5–8 ). All legs shorter than idiosoma. All tarsi with smooth claws and well developed empodia. Lengths of legs I–IV 202 (203; 197–207), 168 (164; 160–168), 175 (169; 166–175), and 201 (196; 188–201), respectively. Chaetotaxy of legs I–IV (number of solenidia in brackets): tarsi 9(1)-7(1)-7-7, tibiae 4(1)-4(1)-4-4, genua 2(1)-2-2-2, femora 2-2-1-1, trochanters 1-1-2-1. Tibia I seta v” and femur III seta v absent. Tarsal setae u ’ and u ” with very distinct barbs, vs I–II with few small barbs; p ’, p ” and a ' I blunt tipped, slightly wider in middle than at base or tip, a' I with a few barbs near distal end. Other leg segments: dG I–IV, l’G I and dF I–IV squamiform, dTi I –II, l’Ti I, l”Ti II– IV, l’G II–IV and l’Tr III lanceolate, all other leg setae smooth, setiform. Tarsal solenidia located median on tarsi I–II, at level of seta vs.; solenidion ω I of medium length, with a small guard seta ft (5); ω II short. Tibial solenidion Φ I of median length, Φ II short. Genual solenidion σ I short. Empodia I–IV each with 4 (rarely 3–5) pairs of tenant hairs.

Male (N=1) ( Fig 9 ). Body length (including gnathosoma ) 311, maximum width 175. Gnathosoma as in female. Idiosomal length 228, with two dorsal shields. Anterior dorsal shield length 99, maximum width 137; bearing 8 pairs of narrowly squamiform setae (including 4 pairs of “ c ” setae). Humeral setae (c2) situated off dorsal shields, narrowly squamiform, 1/3 longer than anterior-lateral setae. Posterior dorsal shield length 102 and width 132, bearing 5 pairs of narrowly squamiform (d1, d2, e1, e2, f2) and 2 pairs of filiform (h1, f1) setae; setae h2, ps1 and ps2 inserted off the shields, filiform. Ventral setation reduced relative to female, setae g1, g2, and ag3 absent. Leg chaetotaxy as in female, but solenidiotaxy different. Relative to the female, solenidion ω added on tarsi III–IV and solenidion Φ added on tibiae III–IV.

Teleonymph (N=3) ( Figs. 10 –12). Body length (including gnathosoma ) 338 (327–352), maximum width 206 (197–217). Gnathosoma as in female. Idiosomal length 255 (248–263), with 6 dorsal shields: one large anterior and five smaller posterior shields. All dorsal shield setae narrowly squamiform. Anterior dorsal shield length 100 (98– 102), maximum width 172 (169–179), bearing 9 pairs of setae (including 5 pairs of “ c ” setae). Humeral setae (c2) situated off dorsal shields, lanceolate, 70 long (70–71), almost twice as long as anterior lateral setae. Among the 5 posterior shields, the anterior median shield with setae d1, paired anterior lateral shields with setae d2, e1, and e2, and posterior lateral shields with setae f2; setae h1 and h2 inserted off the shields, lanceolate. The genito-anal regions are fused (not adjoining as in the female), and carry the h3, ps1, ps2 and ps3 setae, setae g1, g2 absent. As in the male, the nymph carries only 2 pairs of ag setae (ag3 absent). Leg chaetotaxy and solenidiotaxy as in female.

Collection information. Holotype female: U.S.A.: Florida, Hardee Co., 10 km S of Ona, Lilly, 27°21’59”N 81°57’56”W (test plot 98-5), coll. C. C. Childers, 1 Jun 1998. Paratypes female (same locality and collector), male, 18 Dec 1998, and two nymphs, 20 Jan 1999 (all lot E20098177-2); two paratype females and one nymph from Florida, Lake Co., vicinity of Monteverde, 28°35’53”N 81°40’19”W (test plot 98-6), coll. C. C. Childers, 19 Jan 1999 (OSAL106573–5); one paratype female, Florida, Highlands Co., 6 km SE of Avon Park (27°33’09”N 81°27’23”W) (test plot 2000-3), collector C. C. Childers, 10 Jul 2000 (OSAL106576). All specimens were collected in leaf samples from ‘Hamlin’ oranges.

Deposition types. Holotype female (E2009-8177-1), paratype female (E2009-8177-2a), male (E2009-8177- 2b), and 2 nymphs (E2009-8177-2c–d) in FSCA. Paratype female (OSAL0106573) and paratype nymph (OSAL0106575) in OSAL; paratype female (OSAL0106574) in ZIN.

Etymology. We are pleased to name this species in honor of Dr. George W. Wharton, founder of the Acarology Laboratory, Ohio State University, who made outstanding contributions to acarology.

Figures

FIGURES 9. Lanceacheyla whartoni gen. nov., sp. nov., male. 9, Dorsal view.

FIGURES 1 – 4. Lanceacheyla whartoni gen. nov., sp. nov., female. 1, Dorsal view; 2, Ventral view; 3, Gnathosoma, dorsal view; 4, Genito-anal region.

FIGURES 5 – 8. Lanceacheyla whartoni gen. nov., sp. nov., female. 5, Leg I; 6, Leg II; 7, Leg III; 8, Leg IV.

FIGURES 10 – 11. Lanceacheyla whartoni gen. nov., sp. nov., teleonymph: 10, Dorsal view; 11, Ventral view. Detail view genito-anal region.