Mixozercon jasoniana, Díaz-Aguilar, Irma & Ujvári, Zsolt, 2010

Díaz-Aguilar, Irma & Ujvári, Zsolt, 2010, New zerconid mites (Acari: Mesostigmata: Zerconidae) from Canada, with a review of the genus Mixozercon Halašková, 1963, Zootaxa 2555, pp. 1-29 : 8-12

Mixozercon jasoniana sp. nov.

( Figures 7–11 , 22 , 26 , 30 , 34 )

Material examined. Holotype: female collected in stand 940-DD, plot 6 (56° 49' 5.753'' N, 118° 21' 38.284'' W) at EMEND research study site, northern area, from vascular plants and broadleaf-litter on forest floor, 8.09.2006, leg. Díaz-Aguilar, I. (deposited in CNC). Paratypes: stand 940-DD, plot 6, northern area, from vascular plants and broadleaf-litter on forest floor, 8.09.2006., leg. Diaz-Aguilar, I. (3 females, 1 DN deposited in CNC, 1 female, 2 DN deposited in HNHM); stand 928- MX, plot 1, northeastern area, from vascular plants and leaf-litter on forest floor, 9.09.2006, leg. Díaz-Aguilar, I. (2 females deposited in HNHM, 2 males deposited in CNC); stand 928- MX, plots 1, 2 and 4, northeastern area, from vascular plants and leaflitter on forest floor, 9.09.2006, leg. Díaz-Aguilar, I. (30 females, 5 males, 2 DN); stand 930-CD, plot 4, northeastern area, from mosses and needle leaf-litter on forest floor, 9.09.2006, leg. Díaz-Aguilar, I. (4 females); 940-DD, plot 6, northern area, from vascular plants and broadleaf-litter on forest floor, 8.09.2006., leg. Diaz-Aguilar, I. (23 females, 8 DN).

Diagnosis. Adult female. Central and submarginal setae of podonotum smooth, except j1, z2 and s6. J-, Z- and S-setae of opisthonotum pilose to varying degrees, R1 slightly pilose, other marginal R-setae smooth, thorn-like. Central members of J and Z setal-row inserted on enlarged setal bases. Setae J5 situated between dorsal cavities; Z3 reaching bases of Z4; S1 situated close to Z1, in posterolateral position. Pores Po2 situated inside the line connecting Z1 and Z2. Podonotum covered by circular, squamous pattern, the area between J setal-rows ornamented with relatively large, subtriangular protuberances. Dorsal cavities weakly sclerotised, with undulate anterior margin. Posterior end of peritrematal shield rounded, reaching beyond level of R3. Post-genital sclerites absent.

Description. Female. Length of idiosoma 342–360μm (mean 355); width 244–252μm (mean 250) (n = 7).

Dorsum ( Figs 7 , 22 ). Podonotum, 22 pairs of setae: j-row with six pairs, z-row with two pairs, s-row with six pairs, r-row with six pairs, p-row with two pairs. Setae j1 plumose, z2 and s6 often barbed, s3 elongate, plumose. Other j-, z- and s-setae short, smooth and needle-like. Marginal setae r3 and r6 elongate, plumose, other r setae shorter and delicately pilose (r 1 may be smooth). Peritrematal seta p1 short and smooth, p2 elongate and pilose; both visible in dorsal view. Pores po1 situated on a line connecting the insertions of j2 and s1, po2 lying on a line connecting j4 and s4, near s4, po3 inside the line connecting s5 and s6. Whole podonotum covered by small, circular, irregular squamous ornamentation, mostly arranged in curved lines in the center of the shield ( Fig. 34 ). Circular ornamentation between setae z1 well-developed, strongly sclerotised. Opisthonotum ( Figs 26 , 30 ) with 23 pairs of setae: J-row with six pairs, Z-row with five pairs, Srow with four pairs and R-row with eight pairs. Setae J1-J5 elongate, pilose and pointed, J1 situated close together, distance between their bases 16 μm, J2-J5 diverging further away from each other. Setae J5 situated between dorsal cavities, J6 elongate, brush-like and plumose. Z1–Z3 similar in shape and length to anterior Jsetae, Z3 reaching bases of Z4. Setae Z4 long, broadening distally, brush-like and plumose, Z5 short, delicately pilose. Setae S1 similar in shape and length to Z1, situated close to Z1, distance between their insertions 11 μm. Setae S2-S4 elongate, densely plumose, extending beyond lateral margin of opisthonotal shield. Setae S2 situated anterolateral to Z2. Eight marginal R-setae short, smooth and thorn-like; in some specimens R1 delicately barbed. Setae J1-J5, Z1-Z4 and S1 inserted on broad setal bases. Pores Po2-Po4 enlarged, with undulate margins, Po1 situated anterior to Z1, Po2 axial to a line connecting the insertions of Z1 and Z2, Po3 enlarged, on a line connecting J4 and Z4, Po4 on a line connecting Z5 and S4. Lateral parts of opisthonotum sparsely covered by large, bulging spots, central area around J setae with large, distinct, subtriangular protuberances forming a central star-like pattern. Dorsal cavities weakly sclerotised, uniform, with undulate anterior margin, axes parallel to that of the body. The length of opisthonotal setae and the distances between their insertions as in Table 2 .

female male DN female male DN female male DN Venter ( Fig. 8 ). Posterolateral ends of peritrematal shield arcuate, expanded posteriorly, reaching beyond level of R3 setae. Peritremes straight, with bent anterior tips. Post-genital sclerites absent. Anterior margin of ventri-anal shield with two pairs of setae. Pre-anal setae short simple, post-anal seta elongate, distally pilose. Ventri-anal pores situated lateral to adanal setae. Sternal shield with reticulate ornamentation, ventri-anal shield covered by squamous pattern.

Male. Length of idiosoma 263–267μm (mean 265); width 180μm (n = 2). Chaetotaxy, poroidotaxy and sculpturing pattern of dorsal shields ( Fig. 9 ) similar to female, but setae r 5 may be slightly pilose. On the ventral side ( Fig. 10 ), sternogenital shield with straight posterior margin and five pairs of setae. Peritrematal shield and ventri-anal shield fused laterally, on the level of R3 setae, not separated from the body margin. Post-genital sclerites absent. Ventri-anal shield with one pair of setae on the anterior margin and 17 ventri-anal setae ( Fig. 10 ). The length of opisthonotal setae and the distances between their insertions as in Table 2 .

Deutonymph ( Fig. 11 ). Length of idiosoma: 275–283μm (mean 280); width 178–188μm (mean 185) (n = 3). Setae j1 barbed, s3, r3 and r6 long, brush-like, plumose, other podonotal setae smooth, simple. Chatetotaxy and poroidotaxy of opisthonotum as in adult stages. Podonotal circular, irregular-squamous pattern and circular sclerotised markings weakly developed, central and lateral parts of opisthonotum covered by circular protuberances. The length of J, Z and S setae and the distances between their insertions as in Table 2 .

Protonymph and larva. Unknown.

Etymology. The species is dedicated to Mr. Jason Edwards, EMEND field coordinator.

Remarks. There is a difference in the number of setae on the anterior margin of the ventri-anal shield between male and female specimens. All females observed bear two pairs of setae on the anterior margin of ventri-anal shield, in contrast to male specimens, which generally had one pair of setae but sometimes two. Mixozercon jasoniana is closely related to M. albertaensis sp. nov., and M. borealis sp. nov. by the shape of the dorsal cavities and the presence of enlarged setal bases, and also resembles M. s tellifer on the basis of the similar sculpturing pattern and the pilosity of J-, Z-, and S-setae. The four species can be distinguished from each other according to the particular characteristics given in Table 4 .

Figures

FIGURE 7. Mixozercon jasoniana sp. nov., dorsal view of female.

FIGURES 8 – 11. Mixozercon jasoniana sp. nov. 8. Ventral view of female; 9. Dorsal view of male; 10. Ventral view of male; 11. Dorsal view of deutonymph.

FIGURES 21 – 24. Females of the new species, dorsal view, SEM photos (scale bar 100 µm). 21. Mixozercon albertaensis sp. nov.; 22. Mixozercon jasoniana sp. nov.; 23. Mixozercon borealis sp. nov.; 24. Boreozercon emendi sp. nov.

FIGURES 25 – 28. Central surface of opisthonotum of the new species, SEM photos (scale bar 25 µm). 25. Mixozercon albertaensis sp. nov.; 26. Mixozercon jasoniana sp. nov.; 27. Mixozercon borealis sp. nov.; 28. Boreozercon emendi sp. nov.

FIGURES 29 – 32. Lateral surface of opisthonotum of the new species, SEM photos (scale bar 25 µm). 29. Mixozercon albertaensis sp. nov.; 30. Mixozercon jasoniana sp. nov.; 31. Mixozercon borealis sp. nov.; 32. Boreozercon emendi sp. nov.

FIGURES 33 – 36. Central surface of podonotum of the new species, SEM photos (scale bar 25 µm). 33. Mixozercon albertaensis sp. nov.; 34. Mixozercon jasoniana sp. nov.; 35. Mixozercon borealis sp. nov.; 36. Boreozercon emendi sp. nov.

Tables

TABLE 2. Length of opisthonotal setae and longitudinal distances between their bases in Mixozercon jasoniana sp. nov. (measurements in µm).

I1	23	16	13	Z1	22	14	11	S1	24	16	17
I1-I2 I2	40 24	30 16	32 16	Z1-Z2 Z2	34 28	23 17	29 16	S1-S2 S2	28 36	22 25	24 32
I2-I3	29	19	21	Z2-Z3	25	21	23	S2-S3	45	32	37
I3 I3-I4	24 26	19 17	16 23	Z3 Z3-Z4	28 27	18 23	19 23	S3 S3-S4	36 55	26 34	30 40
I4	29	17	18	Z4	39	23	34	S4	37	27	33
I4-I5 I5	31 28	28 18	25 15	Z4-Z5 Z5	57 16	38 11	38 10
I5-I6	29	20	18
I6	35	26	33