Picobia corcoracus, Skoracki & Glowska & Sikora, 2008

Skoracki, Maciej, Glowska, Eliza & Sikora, Bozena, 2008, Four new species of the quill mite genus Picobia Heller, 1880 (Acari: Syringophilidae) parasitizing birds in the Australian Region, Zootaxa 1961 (1), pp. 58-68 : 64-67

Picobia corcoracus sp. nov.

( Figs 20–27 )

Description. Female. ( Figs 20–27 ). Total body length 2530 in holotype (physogastric form). Gnathosoma . Chelicerae edentate. Hypostomal apex hilly ( Fig. 20 ). Each transverse and longitudinal branch of peritremes with 7–8 chambers ( Fig. 20 ). Length of stylophore 270. Idiosoma . Propodosomal shield divided into two sabre shaped lateral sclerites bearing setae ve and sci ( Fig. 23 ). Setae vi and ve subequal in length, both 1.4 times shorter than sci. Bases of setae vi and ve set at the same level. Setae vi, ve and sci strongly knobbed ( Fig. 22 ). Bases of setae d1 situated anterior to the level of setae sce bases. Hysterosomal shield invisible. Pygidial shield well sclerotized and punctated, bearing bases of setae d4 and l4 ( Fig. 25 ). Length ratio of setae d4:l4 1:1.8. Bases of setae ic1 fused ( Fig. 21 ). Paragenital setae pg1 slightly longer (1.3 times) than pg2. Length ratio pg2:pg3 1:1.7. Setae pg1 set anterior to level of setae pg2. Two pairs of anal setae present. Genital setae short and thick ( Fig. 26 ). Opisthosomal lobes developed. Legs. Coxal fields I–IV well sclerotized. Dorsal setae of legs I and II slightly knobbed. Antaxial and paraxial members of claws pair III and IV subequal in size ( Fig. 27 ). Setae cxIII2 about 3 times longer than cxIII1. Lengths of setae: vi 250; ve 205; sci 285; sce 420; l1 405; l4 185; d1 355; d4 95; d5 95; pg1 155; pg2 115; pg3 195.

MALE. Unknown.

Type material. Female holotype (Syr. 123) from the White-winged Chough Corcorax melanorhamphos (Vieillot) ( Passeriformes : Grallinidae ), Australia, no other data. Host specimen is deposited at MNHW. Holotype is deposited at AMU.

Etymology. The name corcoracus refers to the generic name of the host and is a noun in apposition.

Differential diagnosis. Picobia corcoracus sp. nov. is closely related to P. sturni Skoracki, Bochkov et Wauthy, 2004 described from Sturnus vulgaris Linnaeus (Sturnidae) ( Skoracki et al. 2004). In females of both species, the hypostomal apex is hilly, the bases of setae vi and ve are situated at the same transverse level, the bases of setae d1 are situated anterior to the level of setae sce bases, and the pygidial shield and two pairs of anal setae are present. This new species differs from P.sturni by the following characters: in females of P. corcoracus sp. nov., the peritremal transverse branch has 7–8 chambers; the sabre shaped propodosomal shields bear setae ve and sci; and the bases of paragenital setae pg2 are situated closer to bases of setae pg1 than to pg3 bases. In females of P. sturni , the peritremal transverse branch has 3–4 chambers; the lateral propodosomal shields bear setae ve, sci and sce; and the bases of paragenital setae pg2 are situated closer to pg3 than to pg1 bases.

Figures

FIGURES 20–27. Picobia corcoracus sp. nov. (female). 20, gnathosoma in dorsal view; 21, propodosoma in ventral view; 22, seta ve; 23, Propodosoma in dorsal view; 24, opisthosoma in ventral view; 25, opisthosoma in dorsal view; 26, opisthosomal lobe; 27, tarsus III. Scale lines 100 µm (Fig. 25); 75 µm (Figs. 21, 23, 24); 50 µm (Figs. 20, 26), 20µm (Figs. 22, 27).