Euryparasitus occidentalis Hagele, Kaufman, Whitaker & Klompen

Hagele, Thomas, Kaufman, Bruce, Whitaker, John O., Jr & Klompen, Hans, 2005, The genus Euryparasitus in North America (Mesostigmata: Euryparasitidae), Zootaxa 1036, pp. 1-20 : 5-10

Euryparasitus occidentalis Hagele, Kaufman, Whitaker & Klompen n. sp.

( Figs. 1 A, 1B, 2A, 3)

Diagnosis. Deutonymph relatively small. Idiosomal setae smooth, setae r 4, Z 3, and Z 5 distinctly longer than remaining dorsal setae. Chelicerae with 5 teeth on fixed digit, 3 teeth on movable digit. Gnathotectum with smooth anterior free margin. Tarsus I with a distinct acrotarsus.

Description. Idiosomal length 639 (51) and width 421 (33) (N=6).

Gnathosoma. Chelicerae well developed, fixed digit with 5 teeth, movable digit with 3 distinct teeth ( Fig. 1 B). Dorsal seta stout and smooth, dorsal lyrifissure present, poorly developed, lateral lyrifissure i not observed (only two specimens had the chelicerae in a lateral position, and in both the relevant part of the chelicerae was unclear); pilus dentilis small and thin. Gnathotectum with smooth anterior margin extending to a prominent, median prong with a semi blunt point ( Fig. 1 A). Hypostomal setae smooth; setae hyp 1 and hyp 3 much longer than hyp 2. Subcapitular setae (cs) with a few small barbs. Corniculi smooth, hornlike; inserted slightly dorsal. Deutosternum with 7–9 files of teeth; teeth vary in sharpness, relative size, and number per row (from 4–11), and are irregularly distributed within rows. Palps with five distinct segments, tibia and tarsus not fused. Setation standard for free living Dermanyssina ( Evans, 1963b), with 2 setae on the trochanter, 5 on the femur, 6 on the genu, and 14 on the tibia; sensilla on tarsus not counted. Palp pretarsus with three tines, one of which very small.

Idiosoma. Dorsum almost completely covered by two shields of subequal size; shields covered with a reticulate pattern ( Fig. 3 A). Off shield cuticle weakly striate (see Fig. 5 ). All dorsal setae smooth, setiform. Setae r 4, Z 3, and Z 5 relatively long, median and marginal opisthosomal setae shorter; setae j 1 and z 1 short; setae Z 3 about three times the length of setae j 6; setae Z 5 distinctly longer than Z 3. One pair of lateral propodosomal setae, designated px, associated with the peritrematal shield. Dorsal setal complement nearly complete for jJ, zZ, and sS series (only s 1 lacking). Most R and Rv setae (designations tentative) inserted in soft cuticle. Complement of dorsal lyrifissures and glands similar to that listed for Zerconidae ( Johnston & Moraza, 1991) , but lacking lyrifissures idz 4, idS 2, and, possibly idR 3, and opisthosomal glands gdJ 2, gdJ 3, gdJ 4, and gdZ 1. The pairs of lyrifissures and glands designated in Zerconidae as ids 4 and gds 5 ( Johnston & Moraza, 1991) are most probably homologous to the pair designated as ids5 and gds 6 in Parasitidae ( Al­Atawi et al., 2002) . Glands gds 6 relatively large.

Venter ( Fig. 3 B). Tritosternum with well developed laciniae. Large sternal shield with faint reticulation, including insertions of setae st 1– st 4. Setae st 5 inserted in soft cuticle, flanking posterior end of sternal shield. Relative size of sternal setae decreases gradually from st 1 to st 5. Endopodal shields distinct, exopodal shields weakly developed, not fused to peritrematal shields. Stigmata at level of middle of coxal acetabula IV; peritremes extending anteriorly until the middle of coxal acetabula I. Peritrematal shields not very extensive. Metapodal shields small, without setae, glands or lyrifissures. Anal shield nearly round; para­anal setae inserted at the level of center of the anal valves; unpaired postanal seta slightly longer than para­anal setae. Cribrum transverse, linear, poorly developed. Opisthogastral setae relatively short, only Sv 5 slightly longer. All ventral setae smooth and setiform. All 3 sternal lyrifissures well developed, peritrematal shield with lyrifissures ip 1 and ip 2, and gland gp. Opisthogastral glands gv 2 close to coxae IV, multiple; glands gv 3 at margin of anal shield; sternal glands gv 1 not observed. Opisthogastral lyrifissures as in Zerconidae ( Johnston & Moraza, 1991) , but lyrifissure pair ivo 3 may be absent (the identity of the lyrifissure between setae Rv 3 and Rv 4 is unclear; it may be homologous to ivo 3 or idR 3).

Legs. Tarsus I with distinctly delineated acrotarsus, and partial basitarsal fissure. Legs II thickened. Leg setation: Coxae: 2–2–2–1; Trochanters: 6–5–5–5; Femora I: 2 3/1 2/3 2; II: 2 3/1 2/2 1; III–IV: 1 2/1 2/0 0. Genua I: 2 3/2 3/1 2; II: 2 3/1 2/1 2; III: 2 2/1 2/1 1; IV: 2 2/1 3/1 1. Tibiae I: 2 3/2 3/2 2; II: 2 2/1 2/1 2; III: 2 1/1 2/1 1; IV: 2 1/1 3/1 2. Tarsi II–IV 3 3/2 1/1 3/2 3/3; setae ad 1, pd 1 small. thin and somewhat ribbon like, occasionally not observed. Ventral setae of tarsus and tibia II smooth, setiform, only slightly thicker than dorsal setae. All legs with a well developed pretarsus including two claws.

Material examined (all deutonymphs). CANADA: British Columbia, Hope, 11.5 mi SW of, 49°23'N, 121°26'W, ex Neurotrichus gibbsii (Talpidae) (GSJ1746), 8 Jul 1973, coll. Jones, G. S., OSAL 013769 (Holotype). Paratypes: Same locality and date, ex Neurotrichus gibbsii (GSJ1741), coll. Jones, G. S., OSAL 013768; Jct BC16 & "Nantleg" Rd, ex Microtus sp. ( Muridae ) (GSJ1244), 2 Aug 1972, coll. Jones, G. S., OSAL 013766.

U.S. A: Colorado, Grand Co., Jones Pass, 1 mi S of, 39°46'25"N, 105°53'19"W, 3475 m, ex Microtus longicaudus (DMA2021), coll. Armstrong, D. M., OSAL 013795; Oregon, Benton Co., Mary's Peak, 4 mi from jct. sr344 & forest rd 1244, 44 °30'16"N, 123°33'00"W, ex Sorex bendirii (Soricidae) (GSJ1035), 14 Jul 1972, coll. Jones, G. S., OSAL 013763; Mary's Peak, 32 km SW Philomath, ex Sorex pacificus (GSJ1047), 14 Jul 1972, coll. Jones, G. S., OSAL 013764; Mary's Peak, station 1, 32 km SW Philomath, ex Arborimus albipes (Muridae) (GSJ1645), 28 Jun 1973, coll. Jones, G. S., OSAL 013767; Benton Co., 44°30'N, 123°25'W, ex Sorex pacificus (CM1034), 24 Mar 1968, coll. Maser, C. O., OSAL 013772–73; ex Sorex trowbridgii (CM1042), 21 Mar 1968, coll. Maser, C. O., OSAL 013771; Clackamas Co., Estacada Quadrangle, 4517'23"N, 122°19'57"W, ex Mustela erminea (Mustelidae) , 31 Jul 1969, coll. Maser, C. O., OSAL 013787–90; Coos Co., Bandon, SE of, 43°07'09"N, 124°24'26"W, ex Sorex pacificus (CM2962), 27 Dec 1971, coll. Maser, C. O., OSAL 013780; Bandon, 4 mi NNE of, ex Peromyscus maniculatus (Muridae) (CM2511), 25 Feb 1971, coll. Maser, C. O., OSAL 013776; Bandon, E of, ex Peromyscus maniculatus (CM3267), 16 Jul 1972, coll. Maser, C. O., OSAL 013804; Coos Co., 43°29'N, 124°00'W, ex Sorex trowbridgii (CM2495), 21 Jan 1971, coll. Maser, C. O., OSAL 013759; ex Arborimus albipes (RML59592), 3 Jun 1970, coll. Maser, C. O., OSAL 013756; Curry Co., Brookings, 16 km E of, ex Scapanus orarius (Talpidae) (CM3144), 21 Apr 1970, coll. Maser, C. O., OSAL 013803; Curry Co., 42°30'N, 124°13'W, CM2462, ex Neurotrichus gibbsii (CM2462), 4 Dec 1970, coll. Maser, C. O., OSAL 013785–86; Douglas Co., Reedsport, SW of, 43°42'09"N, 124°05'44"W, 3 m, ex Arborimus albipes (RML62993), 22 Mar 1972, coll. Maser, C. O., OSAL 013760; Douglas Co., 43°20'N, 123°10'W, ex Sorex pacificus (CM2091), 5 Feb 1970, coll. Maser, C. O., OSAL 013775; Lane Co., H. J. Andrews Exp. Forest, 43°55'N, 122°50'W, ex Neurotrichus gibbsii (CM6115A), 14 Aug 1972, coll. Maser, C. O., OSAL 013793–94; ex Sorex pacificus , (CM3387), 12 Aug 1972, coll. Maser, C. O., OSAL 013784; ex Peromyscus maniculatus , 5 Apr 1972, coll. RAN, OSAL 013791; Lincoln Co., Cascade Head Exp. Forest, 45°02'03"N, 123°55'20"W, ex Sorex bendirii (CM3305), 13 Aug 1972, coll. Maser, C. O., OSAL 013781; ex Sorex bendirii (CM3310), 15 Aug 1972, coll. Maser, C. O., OSAL 013782; ex Sorex pacificus (CM2600), 27 Apr 1971, coll. Maser, C. O., OSAL 013778; ex Arborimus albipes (RML59829), 4 Aug 1972, coll. Maser, C. O., OSAL 013757; ex Arborimus albipes (RML59835), 7 Aug 1972, coll. Maser, C. O., OSAL 013758; ex Arborimus albipes (RML63008), 12 Aug 1972, coll. Maser, C. O., OSAL 013761; ex Arborimus albipes (RML63010), 19 Aug 1972, coll. Maser, C. O., OSAL 013762; ex Microtus oregoni (CM2573), 14 Apr 1971, coll. Maser, C. O., OSAL 013777; ex Zapus trinotatus (Dipodidae) (CM2743), 8 Aug 1971, coll. Maser, C. O., OSAL 013779; Lincoln Co., 44°40'N, 123°50'W, ex Sorex bendirii (CM3329), 18 Aug 1972, coll. Maser, C. O., OSAL 013783; ex Sorex pacificus , 16 Aug 1972, coll. Maser, C. O., OSAL 013792; Linn Co., 44°30'N, 122°35'E, ex Peromyscus maniculatus (CM1949), 2 Nov 1969, coll. Maser, C. O., OSAL 013774; Washington, Clallam Co., Olympic Nat. Pk., forest rd. 304, 48 °16'00"N, 124°40'30"W, ex Peromyscus sp. (GSJ1090), 18 Jul 1972, coll. Jones, G. S., OSAL 013765; Snohomish Co., Gold Bar, 48°03'N, 121°43'W, ex Neurotrichus gibbsii ( JOW 6953), 24 Jun 1971, coll. Whitaker, J. O., Jr., OSAL 013770.

Deposition of types. Holotype deutonymph, OSAL 013769, in OSAL. Paratypes in collection of OSAL, CNC, JOW, NMNH, UMMZ, and ZIN.

Etymology. The species name refers to the western North American distribution of this species.

Remarks. Euryparasitus tori , E. longicheta , E. goncharovi , and E. occidentalis differ from all other described Euryparasitus deutonymphs by the complete absence of barbed setae on the idiosoma, the presence of a gnathotectum with a completely smooth margin, the presence of an acrotarsus on legs I, and the presence of 5 teeth on the movable digit, and 3 teeth on the fixed digit of the chelicerae. However, E. longicheta has much longer setae than all others ( Bondartchuk & Buyakova, 1978), and E. goncharovi has a more or less pentagonal shaped anal shield with dorsal setae that are all subequal in length ( Bondartchuk & Buyakova, 1976). Euryparasitus occidentalis and E. tori share elongate setae Z 5 and an almost round anal shield (especially distinct in E. tori ). However, setae Z 3 in E. tori are similar in length to setae Z 2 and S 3 ( Davydova, 1970), while they are distinctly longer in E. occidentalis . Setae Z 5 in E. occidentalis are almost half as long as the opisthosomal shield, in E. tori those setae are at most 1/3 the length of that shield.

The presence of an acrotarsus on legs I is an unusual character for Dermanyssina, and is more commonly associated with deutonymphs of Parasitidae . Continued assignment of the above group of species to Euryparasitus , rather than some genus of Parasitidae is based in part on the morphology of the cribrum (a thin row lining most of the posterior margin of the anal shield in all Euryparasitus , a triangular field in parasitid deutonymphs), and the multiplication of ventral glands gv 2 (single in Parasitidae ). There is also evidence from the adults. While only the deutonymphs of E. occidentalis , E. longicheta , and E. tori are known, E. goncharovi is known from both nymphal instars and the adults. Its female has the sternal and metasternal shields fused, with seta st 4 on the sternal shield, and a subrectangular genital shield, characteristics of, respectively, Rhodacaroidea, and Euryparasitidae sensu Anthony (1980) . The male shows a free spermatotodactyl (fused in Parasitidae ) with the massive elongate shape typical for Euryparasitus and Cyrtolaelaps . Based on this evidence we continue to assign these species to Euryparasitus . This assignment implies that the occurence of an acrotarsus on legs I of the deutonymph is homoplasious, with separate origin or retention in Parasitidae and some Euryparasitus .

Lee (1970) noted a ventral setal complement in adult E. emarginatus of 3 Jv, 3 Zv, 3 Sv, and 3 Rv setae. E. occidentalis deutonymphs carry one less Rv seta.

Figures

FIGURE 1. Euryparasitus deutonymphs, gnathotectum (A, C, E) and chelicerae (B, D, F). A, B: E. occidentalis n. sp.; C, D: E. maseri n. sp.; E, F: E. calcarator (Banks).

FIGURE 3. Euryparasitus occidentalis n. sp., deutonymph. A: dorsal view; B: ventral view.

FIGURE 5. Euryparasitus maseri n. sp., deutonymph. A: dorsal view; B: ventral view.