Mixozercon albertaensis, 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 : 4-8

Mixozercon albertaensis sp. nov.

( Figures 1–6 , 21 , 25 , 29 , 33 )

Material examined. Holotype: female collected in stand 867- MX, plot 2 (56° 44' 36.370'' N, 118° 22' 35.480'' W) at EMEND research study site, southern area, from vascular plants and leaf-litter on forest floor, 8.09.2006, leg. Díaz-Aguilar, I. (deposited in CNC). Paratypes: stand 867- MX, plot 4, southern area, from vascular plants and leaf-litter on forest floor, 8.09.2006, leg. Díaz-Aguilar, I. (1 female deposited in HNHM); stand 852-DD, plot 1, southeastern area, from vascular plants and broadleaf-litter on forest floor, 11.09.2006, leg. Díaz-Aguilar, I. (1 female, 1 male deposited in CNC); stand 864-DD-CC, southern area, from grassed forest floor, 7 years after harvested, 10.09.2006, leg. Díaz-Aguilar, I. (1 female deposited in HNHM); stand 889-CD, plot 6, southwestern area, from mosses and needle leaf-litter on forest floor, 9.09.2006, leg. Díaz- Aguilar, I. (1 female, 1 male deposited in CNC, 1 female, 1 male deposited in HNHM); stand 862-DD, plots 2, 4 and 5, and stand 852-DD, plots 1, 2 and 6, southern and southeastern areas, from vascular plants and broadleaf-litter on forest floor, 10– 11.09.2006, leg. Díaz-Aguilar, I. (43 females, 14 males, 7 PN, 16 larvae); stand 867- MX, plots 1, 2 and 4, and stand 902- MX, plots 1, 3 and 6, southern and southwestern areas, from vascular plants and leaf-litter on forest floor, 8– 10.09.2006, leg. Díaz-Aguilar, I. (35 females, 7 males, 1 PN, 17 larvae); stand 889-CD, plot 6, southwestern area, from mosses and needle leaf-litter on forest floor, 9.09.2006, leg. Díaz-Aguilar, I. (6 females, 7 males); stand 864-DD-CC, southern area, from grassed forest floor, 7 years after harvested, 10.09.2006, leg. Díaz-Aguilar, I. (1 female, 1 male).

Diagnosis. Adult female. Central and submarginal setae of podonotum smooth, except j1 and j2. Setae J1, Z1, S1 and marginal setae R1-8 smooth, other opisthonotal setae pilose to varying degrees. Central members of J and Z setal row inserted in enlarged setal bases. Setae J5 situated above the line of dorsal cavities. Z3 not reaching the bases of Z4. Setae S1 situated lateral to Z1. Pores Po2 situated on a line connecting Z1 and Z2. Medial part of podonotum covered by tile-like pattern, the area between J setal rows densely ornamented by small, irregular depressions. Dorsal cavities weakly sclerotised, with undulate anterior margin. Posterior ending of peritrematal shield straight, reaching beyond the level of setae R1. Post-genital sclerites present.

Description. Female. Length of idiosoma 335–360μm (mean 350); width 240–260μm (mean 250) (n = 6).

Dorsum ( Figs 1 , 21 ). Podonotum with 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 densely pilose, j2 lightly pilose, s3 elongate, pilose. Other j-, z- and s-setae short, smooth and needle-like. Marginal seta r1 short and smooth, r3 and r6 elongate and plumose, others shorter and densely pilose. Pores po1 situated above the line connecting the insertions of j2 and s1, po2 lying on a line connecting j4 and s4, po3 on a line connecting s5 and s6. Peritrematal seta p1 short and smooth, and p2 elongate and pilose; both visible in dorsal view. Lateral parts of podonotum covered by small, circular, squamous ornamentation; central parts with irregular, tile-like pattern ( Fig. 33 ). Ornamentation between setae z1 weakly developed. Opisthonotum with 23 pairs of setae ( Figs 25 , 29 ): J-row with six pairs, Z-row with five pairs, S-row with four pairs and R-row with eight pairs. Setae J1 short, smooth, distance between their bases 41 μm. Setae J2-J5 similar in shape and length, pilose and pointed, J5 situated above the line of dorsal cavities, J6 elongate and plumose. Setae Z1 similar in shape and length to J1, Z2-Z3 delicately pilose. Z4 elongate, brush-like, distally expanded, Z5 short, delicately pilose. Setae S1 smooth, simple, situated laterally to Z1, the distance between their insertions 23 μm. Setae S2-S4 elongate, densely plumose, extending beyond the lateral margin of opisthonotum. Setae S2 situated posterolateral to Z2. J-, Z- and S- setae not reaching the bases of the following setae. Setal bases of J2-J5 and Z2-Z4 prominently enlarged. Marginal setae R short, smooth, thorn-like. Pores Po1 situated anterolateral to Z1, Po2 on a line connecting the insertions of Z1 and Z2, Po3 enlarged, on a line connecting J4 and Z4, Po4 inside the bases of setae S4. Lateral and posterior parts of opisthonotum densely covered by large, distinct, bulging spots. Central area between J setae with irregular depressions (foveolate) forming circles of 6–7. Dorsal cavities weakly sclerotised, uniform, with undulate anterior margin and with axes parallel to that of the body. Length of opisthonotal setae and the distances between their insertions as in Table 1 .

female male PN female male PN female male PN Venter ( Fig. 2 ). Slit between peritrematal shield and body margin relatively narrow. Posterior ends of peritrematal shield truncated, straight, reaching beyond the level of R1. Peritremes straight, with curved anterior section. One pair of narrow post-genital sclerites present. 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 anterolateral to adanal setae. Sternal shield with reticulate ornamentation, ventri-anal shield covered by squamous pattern.

Male. Length of idiosoma 270–278μm (mean 275); width 192–200μm (mean 195) (n = 3). Chaetotaxy, poroidotaxy and sculpturing pattern of dorsal shield ( Fig. 3 ) similar to those of female, except setae j2 and Z5 smooth. Sternogenital shield weakly sclerotised, posteriorly rounded, bearing five pairs of setae. Post-genital sclerites oblong, situated between adgenital gland openings. Peritrematal shield and ventri-anal shield fused laterally, between level of setae R2 and R3, not separated from the body margin ( Fig. 4 ). Anterior margin of ventri-anal shield with two pairs of setae. Length of opisthonotal setae and the distances between their insertions are as in Table 1 .

Deutonymph. Unknown.

Protonymph ( Fig. 5 ). Length of idiosoma 220–225 μm (mean 223); width 147–152 μm (mean 150) (n = 3). Podonotal setae s4-s5 and r3 elongate, brush-like, plumose, others short, smooth and needle-like. Opisthonotal setae J1, J2, J3, J5 short, smooth or barely pilose, J4 distinctly pilose. Setae Z1-Z2 similar to short J-setae, needle-like. Setae Z3 longer, delicately pilose, other members of J, Z and S setal-rows elongate, brush-like, densely plumose. Setae R1 short, smooth, thorn-like. Pores Po3 situated on a line connecting the bases of J4 and Z4. Dorsal cavities as in adult stages. Surface of podonotum smooth, opisthonotal shield with some irregular posterolateral pits, irregular depressions between J and Z rows weakly developed. Length of J, Z and S setae and distances between their insertions are as in Table 1 .

Larva ( Fig. 6 ). Length of idiosoma 208–230μm (mean 220); width 170–182μm (mean 178) (n = 4). Podonotal setae elongate, densely plumose. Opisthonotal setae J2, J3, J5, Z2 and S2 short and simple, others elongate, densely plumose. Well-sclerotised parts of dorsal idiosoma with a reticulate pattern, surface of opisthonotum covered by small cavities lying at intersections of a reticulate ornamentation. Dorsal cavities situated in a row, the medial pair fused.

Etymology. The species is named after the Canadian province of Alberta where it was collected.

Remarks. Mixozercon albertaensis is closely related to M. jasoniana sp. nov., and M. borealis sp. nov. by the shape of dorsal cavities and the presence of enlarged setal bases, but these species can easily be distinguished according to the features given in Table 4 .

Figures

FIGURE 1. Mixozercon albertaensis sp. nov., dorsal view of female.

FIGURES 2 – 6. Mixozercon albertaensis sp. nov. 2. Ventral view of female; 3. Dorsal view of male; 4. Ventral view of male; 5. Dorsal view of protonymph; 6. Dorsal view of larva.

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 1. Length of opisthonotal setae and longitudinal distances between their bases in Mixozercon albertaensis sp. nov. (measurements in µm).

I1	13	11	7	Z1	14	9	7	S1	15	10	21
I1-I2 I2	35 24	21 18	20 9	Z1-Z2 Z2	29 20	22 13	21 8	S1-S2 S2	34 33	31 25	22 23
I2-I3	30	23	19	Z2-Z3	27	20	15	S2-S3	45	30	20
I3 I3-I4	25 33	17 19	9 18	Z3 Z3-Z4	21 34	16 26	13 17	S3 S3-S4	33 49	25 35	24 23
I4	23	18	10	Z4	40	30	26	S4	35	28	27
I4-I5 I5	28 26	23 19	23 8	Z4-Z5 Z5	51 13	44 10	25 7
I5-I6	32	33	11
I6	34	28	27