Porrhotegaeus catherinae, Colloff, 2023

Colloff, Matthew J., 2023, The oribatid mite superfamily Eutegaeoidea (Acari, Oribatida), with descriptions of new taxa from Australia and New Caledonia and a re-assessment of genera and families, Zootaxa 5365 (1), pp. 1-93 : 75-76

Porrhotegaeus catherinae sp. nov.

( Fig. 39 )

Dimensions. Holotype male length 980 μm, breadth 718 μm. Paratype male length 896 μm, breadth 678 μm. Paratype females (n = 3): mean length 1,097 μm (range 1,088 –1,103 μm); mean breadth 753 μm (range 735–781 μm). Ratio of prodorsum to total length: 0.39 (holotype).

Description of adult. Prodorsum: rostrum acute, prominent, anterior margin transverse; rostral setae (ro) long, with spinose ornamentation, on short tubercles on lateral margin of rostrum. Lamellae broad, with reticulate microsculpture, lateral margins strongly convex, smooth; cusps broadly separated medially, with two broadly-separated apical teeth, bases incised medially; lamellar setae (le), long, curved, with spinose ornamentation, emerging from ventral surface of lamellar cusp ( Fig. 39a ). Bothridia long, corniculate, extending beyond lateral margins of lamellae, with slight fold anterior of bothridium; bothridial seta long, smooth, bacilliform.

Notogaster: ratio of length to breadth: 0.85; notogaster rounded, flat, smooth, without obvious cerotegument; dorsosejugal scissure transverse, incomplete medially. Humeral process long, with reticulate microsculpture, pointed, reflexed ventrally, margins smooth, lateral margin slightly concave basally; medial margins convex: incised and folded over basal part of humeral process ( Fig. 39a ). Lyrifissures ia and im not visible. With nine pairs of long, stout, marginally-positioned setae with fine spines, their bases projecting vertically; with complete l, h and p series (h 1 is present); setae la positioned on central part and lm on basal part of humeral process; setae p 2 and p 3 markedly shorter than other setae; setae p 1 positioned dorsally and same length as l and h series.

Ventral aspect: subcapitulum acute, narrow; subcapitular setae h extremely long, thin; a and m shorter. Chelicerae chelate-dentate and of normal proportions. Tutorium broad, curved, with sharp apex, margin serrated ( Fig. 39b ). Epimeral plates not discrete in midline, sub-rectangular to trapezoid, plates I and II large, plates III and IV fused, much smaller than others; epimeral setation 3-1-3-3; setae well-developed, 1b longer than others. Apex of pedotectum I (pd I) right-angled; pd II broad, lobed, with blunt point, protruding laterally; discidium curved, acutely pointed apically; posterior tubercles of enantiophysis E4 present, perigenital carina absent. Ventral plate ovoid, broader than long. Genital and anal plates separated by distance of third of length of genital plate; genital plates 97 µm long, with six pairs of short setae sub-equal in length, g 4 displaced laterally; three pairs of short thin adanal setae; lyrifissure iad in para-anal position, some distance from anal plate, more than length of iad. Anal plates lozenge-shaped, 120 µm long. Pre-anal organ (po) T-shaped.

Etymology. This species is named in honour of my friend and former colleague, Cate Lemann, in honour and recognition of her many years of dedicated service to the Australian National Insect Collection.

Type designation, material examined and locality data. Holotype male, ANIC accession no. 53-1093, paratypes: one male, four females, ANIC accession no. 53-1094, leaf litter, under Syzygium fullagarii (scalybark), closed forest, 100 m east of Soldier Creek , Lord Howe Island, 31°33’10”S, 159° 4’52”E, coll. I. Hutton and K. Lees, 8.vi.2003.

Diagnosis. Porrhotegaeus catherinae can be distinguished from other species in the genus by the following combination of characters: (1) the transverse rostrum; (2) the very long rostral setae; (3) the bases of the lamellar cusps with medial incisions; (4) the lamellar cusps with two broadly-separated apical teeth; (5) the reticulate microsculpture on the lamellae; (6) the reticulate microsculpture on the humeral process; (7) the notogastral setae la and lm positioned near the centre and at the base of the humeral process, respectively, with a large gap between lm and lp; (8) the very short setae p 2 and p 3; (9) the broad tutoria with serrated margins; (10) the large, broad pedotectum II with a blunt, pointed apex.

Remarks. Porrhotegaeus catherinae is not particularly morphologically similar to P. githabul , P. ornatus or P. herminae , particularly in the morphology of the lamellae and lamellar cusp, though it shares with P. herminae the large, leaf-shaped pedotectum II, though lacks the faint perigenital carinae and posterior tubercles of enantiophyses E4 of the latter species.

Figures

FIGURE 39. Porrhotegaeus catherinae sp. nov., adult (a) dorsal aspect; (b) ventral aspect. Scale bar = 200 μm.