Pedrocortesella impedita, Hunt, 1996

Hunt, Glenn S., 1996, A review of the genus Hexachaetoniella Paschoal in Australia (Acarina: Cryptostigmata: Pedrocortesellidae), Records of the Australian Museum 48 (3), pp. 223-286 : 258-262

Pedrocortesella impedita n.sp.

Figs 27, 28

Type material. Western Australia: HOLOTYPE adult, WAM, Mount York , ca 31°53'S 116°48'E, berlesate of she-oak litter, J. Bannister, 16 November 1991 . PARATYPE adults. ANIC, same data as holotype, 2 adults ; AM KS46541 , SEM stub no. S/40l (ill), same data, 3 adults ; AM KS46542 , SEM stub no. S/420, York , 31°53'S 116°46'E, berlesate Powder bark! Mallee litter, J. Bannister, 2 November 1991, 1 adult .

New South Wales: ZMK, 9.6 km S. of Gilgandra , 31°49'S 148°39'E, dry sc1erophyll, ANIC berlesate 89, L.A. Mound, 6 June 1968, 2 adults .

Other material examined. New South Wales: ANIC, 13 km S. of Collarenebri , 29°34'S 148°35'E, berlese extraction Geijera leaf litter, ANIC berlesate 88, L.A. Mound, 5 June 1968, 1 adult ; ANIC, 9.6 km S. of Gilgandra , 31°49'S 148°39'E, dry sc1erophyll, ANIC berlesate 89, L.A. Mound, 6 June 1968, 13 adults ; AM KS4368l , same data, 2 adults ; FMNH, same data, 2 adults ; CNC, same data, 2 adults ; AM KS46543 SEM stub no. S/244, same data, 1 adult .

South Australia: AM KS46501 , SEM stub no. S/222, 3.2 km W. Sherlock , ANIC berlesate 182, R.W. Taylor, 12 Jan 1970, 4 adults ; AM KS46545 , SEM stub no. S/216, 25 km E. by N. of Kimba , 33°05'S 136°41'E litter at base of Mallee, ANIC berlesate 741, A. Calder, 4 Sept. 1981 3 adults .

Diagnosis. Body medium, length about 500-600 flm; scalps rarely (if at all) carried by adult; sensillus with long flattened tuberculate blade; notogaster reticulatealveolate; 5 pairs of notogastral setae, each arising from a large pit set on a conspicuous mound, genitoanal chaetotaxy 7:1:2:3, genital setae in slightly arcuate file, insertion of seta ad3 adjacent to posterior half of anal valve; claw stalk very short.

Description

ADULT: Body: brown; length 570 /lm. Cerotegument: body generally with thin veneer of cerotegument; reticulations on prodorsum and notogaster and rim of bothridium highlighted with crests of cerotegument (Fig. 27 e-E). Setae ro and le and notogastral setae without obvious cerotegument. Legs with cerotegument capping surface sculpturing, setae without obvious cerotegument. Prodorsum: integument reticulate-alveolate; no carina between le and ro; le dorsolateral, distance between them about 0.5 distance between ra, arising from small pit, ro ventrolateral. Pedotectal tooth similar to P propinqua . Bothridium abutting notogaster (Fig. 27D,G), wall depressed posteromesad, posterolateral carina weak, situated away from notogaster; sensillus length subequal to interbothridial distance, with long flattened tuberculate blade (Fig. 27G), posterior margin of prodorsum forming a smooth arc between bothridia. in small, set about 0.5 bothridial diameter from bothridial wall, at edge of dorsosejugal furrow (Fig. 27D). Exuvial scalps: very dirty scalps loosely held on Gilgandra specimen (not illustrated). Notogaster: oval, length:width 420:300. Intramarginal depression U-shaped. Notogaster reticulate-alveolate particularly mesally but regular pattern breaking down with horizontal crests predominantly more laterally into alveolate-rugose pattern (Fig. 27A); posterior margin not invaginate when viewed from above, with a carina between setae pi when viewed posteriorly (Fig. 27H). Fissura ia oblique, im and ip subparallel to sagittal plane; 5 pairs of moderately short notogastral setae arising from pits atop mounds; hi close, each located just inside posterior margin; pi inserted low on posterior flank, further apart than hi; Ipx, p2x and p3x arise just inside posterolateral flank, their insertions easily visible from above, Ipx closest to fissura ip, inserted posterior to it (Fig. 27F). Gnathosoma : chelicera with prominent shelf ventrolaterally on antiaxial surface of movable finger. Pedipalp tarsus with setae (vt) and I" with very long barbs, cm barbs short; tubercle supporting seta aem moderate height; solenidion omega reaching to base of aem (Fig. 28F). Rutella basally with moderate concave flexure and strong lateral buttressing and with pointed mesad process, transverse striations absent (Fig. 28E). Epimeral region: with depressed area immediately anterior to genital valves (Fig. 28B). Genitoanal region: separation of anal and genital vestibules relatively broad but with interruption to ventral plate microsculpture an with mesal triangular-diamond shaped structure between vestibules (Fig. 28A). Aggenital and adanal areas alveolate-reticulate without pores; genital and anal valves with smaller alveoli of similar depth on both valves. Genitoanal chaetotaxy 7:1:2:3; genital setae in slightly arcuate file (Fig. 28C), but all placed close to mesal suture compared with P. propinqua , gi of similar size to other setae, inserted in notch at inner anterior corner; g5 situated at about 0.5 valve length, g7 inserted well anterior to inner posterior corner; setae ag inserted at level just posterior to g6; setae adi more postanal than P propinqua , ad2 about level with posterolateral corner of anal valve, ad3 level at about 0.5 length of anal valve. Legs. Distal apophysis of tibia overlaps about 40% of tarsus (Fig. 271). Tarsal cluster of leg I placed distodorsally on apophysis, slightly proximodorsal to setae te; ft", omega i and 2 enclosed in welldeveloped almost circular common rim, no partition separating ft" from omega i and 2 (Fig. 27J); ft" longer than solenidia; tarsus with distal recess for receiving retracted unguinal complex (Fig. 27J), stalk very short.

Comments. Pedrocortesella impedita can be mistaken for P. semiretieulata because of a superficial similarity in notogastral sculpturing. It differs in having seven rather than six pairs of genital setae, but the two species are evidently very closely related. They share the condition of a broad separation of the genital and anal vestibules with a mesal triangular-diamond shaped structure between them. The specimens collected near Sherlock and Kimba, South Australia, were noted by Hunt & Lee (1995) under their description of P semiretieulata but not placed in a species.

Etymology. The specific epithet is Latin for "embarrassed" and refers to the fact that my technical assistant recognised two species in a sample from Western Australia where I had recognised one.