Zercon hibernia Moraza, Arroyo & Bolger

Moraza, María Lourdes, Arroyo, Julio & Bolger, Thomas, 2009, Three new species of mites (Acari: Zerconidae) from canopy habitats in Irish forests, Zootaxa 2019, pp. 29-39 : 34-36

Zercon hibernia Moraza, Arroyo & Bolger , sp. nov.

( Figs 9–13 )

Material examined Holotype. Female: Ireland, Co. Laois, Baunreagh, Sitka spruce ( Picea sitchensis ) 85 year old plantation (~ 53º 07' N, 7º 34' W), from middle canopy, slide C5ME-2, altitude: 360 m., 7 November 2005, deposited at MZUNA. Paratypes: 2 females, 4 males, same locality and date, collected in the canopy at different heights (females and one male deposited at MZUNA, 3 males deposited at UCD); 3 females, 2 males, Ireland, Dooary, Co. Laois, in a 17 years old Sitka spruce plantation (~ 52 º 57' N, 7º 15' W), altitude: 260 m., 12 December 2007, in the tree canopy at different heights (2 females and all males deposited at MZUNA, 1 female at UCD); 7 females, Ireland, Co. Kerry, Rennadinna Wood ( Taxus baccata ) in Killarney National Park (~ 52º 02' N, 9º 31' W), altitude 30 m., 6 July 2007, from canopy and moss occurring at different heights in the trees (4 deposited at UCD, 3 at MZUNA); 2 females, Ireland; Co, Kerry, Tomies Wood ( Quercus petreae ) in Killarney National Park (~ 52º 03' N, 9º 35' W), altitude 60 m., 5 July 2007, from moss mats in the lower canopy, deposited at MZUNA; 2 females, Ireland, Co. Offaly, Kinnity oak ( Q. petraea ) forest (~ 53º 10' N, 7º 26' W), from moss collected in the lower canopy, altitude 200 m., 2 August 2007 (deposited at MZUNA).

Diagnosis Anterior margin of ventri-anal shield with two pairs of setae. Dorsal fossae of similar size and appearance. Glands gdZ3 (Po3) situated between setal rows Z and S-, lateral to the line connecting setae Z3 and Z4. Setae J1–J3, not reaching the bases of following setae, similar in length; J4 and J5 longer. Setae Z1, Z2 and Z3 similar in length; setae Z4 and Z5 slightly longer. Seta r3 thicker and with a serrate outline. All dorsal setae with 2–3 spines, sligthly bicarinate. Opisthonotal shield with distinct reticulation in the anterior region and pits in the posterior half. Peritreme bifurcate near stigma, anterior tip curved.

Description FEMALE. Length of idiosoma: holotype 590 (580–605 in 5 paratypes), width 430 (410–430). Length of podonotal shield: 315 (315–345). Length of opisthonotum: 275 (255–275) (N=6).

Dorsum ( Fig. 9 ). Podonotal shield with reticulate pattern; opisthonotal shield showing a reticulate pattern on anterior corners; central opisthonotum and posterior corners have small pits arranged in a reticulate pattern. Podonotum with 20 pairs of setae, setae variable in length ( Fig. 10 ); setae s1, z2 and z3 shorter than other podonotal, setae r1 and r3 on dorso-peritrematal shield. Gland openings distinct; gdj2 (po1) situated between s1 and z2; gdj 4 set on the line connecting j4 and z4; gds4 postero-paraxial to insertion of setae s4. Four pairs of podonotal lyrifissures. Opisthonotum with 20 pairs of setae: setal row J with 5 pairs; J5 longest; setal row Z with five pairs of setae: Z1, Z2 and S2 similar in length to J1, Z3 = S3 and longer than Z1; S4 reaching beyond lateral margin of idiosoma and similar in length and shape to Z3; Z5 similar in length to S5. Marginal setae S1 and R1-R6 not reaching beyond bases of following marginal setae, similar in shape to other marginal dorsal setae, smooth or slightly bicarinate (1–3 spines). Glands gdz6 (Po1) on line connecting setae z6 and Z1, glands gdZ2 (Po2) on line connecting setae S1 and S2; large glands gdJ4 (Po3) antiaxial to line connecting setae Z3 and Z4, and enlarged glands gdS5 (Po4) behind line connecting setae Z5 and S5. Dorsal opisthonotal fossae rounded, of general appearance, similar in size. Dorsal lyrifissures as in Fig. 9 . Length of the opisthonotal setae and distance between setal bases within longitudinal I-, Z-, and S-rows as follows: J1 – J3 (35-37), J4 - J5 (45–48), Z1 = Z2 (33–36), Z3 (47), Z4 (53), Z5 (49), S1 (28–30), S2 (38), S3 (45), S4 (45–48), S5 (53), R (26–29); J1-J2> J2-J3 = J3-J4> J4-J5 (42), Z1-Z2> Z2-Z3 (53) <Z3-Z4 <Z4-Z5 (93), S4-S5 (72); J1-J1 = J2-J2 <J3-J3 = J4-J4<J5-J5.

Venter ( Fig. 11 ). Ventral chaetotaxy, adenotaxy, poroidotaxy and shape of ventral shields typical of the genus. Opistogastric soft cuticle smoothly striate. Sternal shield 93–100 long, 87 wide at level of setae st2, posterior margin slightly concave. Sternal setae smooth and thin; st1 11 long; and st 4 14–19 long; st2, st3 and st4 longer (17–19). Anterior margin of ventri-anal shield with two pairs of setae; 8 pairs of thin and smooth pre-anal setae (17–28); setae JV5 similar shape to other dorsal thickened setae, 43 long. Post-anal seta (30) smooth and longer than pre-anal ones (22). Anal valves with euanal setae and anal lyrifissures. Four gland openings gv2 on rounded platelets, gv3 conspicuous.

Peritreme with distinctive shape, clearly bifurcate and bent at posterior tip, anterior tip strongly curved back towards stigma; peritrematal glands in distinctive area ( Fig. 12 ). Tectum as in Fig. 13 .

MALE. Length of idiosoma 440–485, width 320–340. Dorsum similar to female. Sternogenital shield fused with endopodal elements between coxae II–III and III–IV; with five pairs of setae (st1-st5), and a poorly sclerotized band between setae st1 and st2. Gland openings gv2 located on platelets, similar to female. Ventrianal shield with two pairs of setae in anterior margin. Peritreme shape similar to female but not so strongly curved in the anterior tip.

Notes The new species is closely related to Z. guttulatus Athias-Henriot , Z. subguttulatus Moraza , Z. arcuatus Trägårdh and Z. zelawaiensis Sellnick. These five species have the glands Po 3 in position gdZ3, medially along the line connecting Z3 and Z4 or slightly outwards towards the S setae row. However, the length and/or structure of the opisthonotal setae are different.

Zercon subguttulatus has setae Z3-Z5, S4 and S5 with flattened and hyaline rounded tips and the body size is clearly smaller, while Z. guttulatus has setae J3-J5 different in length (longer, reaching the bases of the following setae) and structure (hyaline rounded tips). Neither of these species has the characteristic peritremal structure of Z. hibernia . Zercon zelawaiensis also has setae of series S with different lengths, but seta S2 is remarkably shorter than in Z. hibernia , up to 5 times shorter than S5, which does not happen in the new species. Another difference is that seta Z4 is extremely long in Z. zelawaiensis .

The most similar species, Z. arcuatus , differs mainly from the new species in the structure of the dorsal setae, which are needle like. The absence of pits in the opisthonotal shield is another difference. The characteristic arcuate and branched peritreme are also distinctive in the new species.

Etymology The species name refers to Hibernia , the old Roman name for Ireland.

The species of Zercon that occur in Britain may be separated in the following key. Details of the geographical distribution of most of these species can be found in Skorupski & Luxton (1996) and Luxton (1998).

Figures

FIGURES 9 – 13. Zercon hibernia Moraza, Arroyo and Bolger, sp. nov.. Female. 9. Dorsal idiosoma; 10. Detail of several dorsal setae; 11. Ventral idiosoma; 12. Detail of peritreme and peritrematal gland; 13. Tectum.