Crassacarus

Bochkov, Andre V, Oconnor, Barry M. & Klompen, Hans, 2015, A review of the mite subfamily Harpirhynchinae (Acariformes: Harpirhynchidae) — parasites of New World birds (Aves: Neognathae), Zootaxa 4023 (1), pp. 1-130 : 66

Genus Crassacarus Bochkov, OConnor and Klompen, gen. nov.

Type species: Crassacarus alexfaini sp. nov., designated here.

Diagnosis. FEMALE. Subcapitulum bearing setae n. Palp with full set of setae, typically elongate (not elongate in C. melanerpes sp. nov.). Setae vF smooth or serrate. Idiosoma not flattened dorso-ventrally, slightly wider than long or its length and width subequal. Anterior part of propodonotum between peritrematal branches and striated cuticle smooth. Dorsal shield distinctly developed, entire, without ornamentation or finely ornamented. Dorsal idiosomal striae not accompanied by tubercles or verrucosities. Idiosomal venter weakly striated, without scales or verrucosities. Full set of idiosomal setae present, except h1 absent. Setae vi, ve, and si not clustered; h2 thickened, whip-like, smooth or serrate; setae 3a situated distinctly anterior to pocket-like vulvar structure. Setae 1a and 3a distinctly shorter than 1c, closely situated to each other. Vulvar slit not longer than 1/3 of idiosomal length. Vulvar apodemes indistinct. Legs I and II inserted laterally; legs III and IV inserted ventro-laterally. Legs I and II consisting of 4 (more rarely 5) articulated segments, without or with weakly developed basal lobes; their pretarsi bearing paired claws without basal angles and ciliated empodium. Tarsi and tibiae I and II with full complement of setae, genua I and II without setae or with 1 seta (l ’), femora I and II with 2 setae (d and v). All leg setae smooth. Leg III consisting of 1–2 articulated segments; basal segment bearing 1 seta (in C. melanerpes sp. nov., this seta probably triplicate), apical segment with several setae. Leg IV consisting of 1 articulated segment bearing several setae.

MALE. Gnathosoma and idiosoma as in female. Genital opening situated in anterior or middle part of dorsal shield. Genital setae 3 pairs. Penis situated posterior to genital opening, straight. Idiosomal and leg I and II setation as in female. Setae vi thin, smooth and short. Legs I and II with 5 articulated segments. Leg I and II setation as in female, except genua I and II each with 3 setae (d, l’, v’). Leg III consisting of 2 articulated segments, preapical segment with 1 seta, apical with several setae. Leg IV consisting of 1 articulated segment with several setae.

Species included: Crassacarus alexfaini sp. nov., C. cylindripalpus ( Fritsch, 1954) comb. nov., C. fritschi sp. nov., C. melanerpes sp. nov., C. sialia sp. nov., C. tinae sp. nov.

Hosts: Passeriformes : Bombycillidae , Cardinalidae , Emberizidae , Fringillidae , Parulidae , Turdidae .

Piciformes : Picidae .

Microhabitats: in ears or in skin cysts; female not remaining in tritonymphal skin.

Etymology. Crassacarus is a noun with masculine gender and is formed by a combination of the Latin words, crassus (adjective—thick, fat, referring to shape of the idiosoma in these mites) and acarus (noun - mite).

Differential diagnosis. The new genus is closest to the genus Harpirhynchus . In females of both these genera, the idiosoma is clearly saccate or at least not flattened dorso-ventrally without a basket-like structure posteriorly, the dorsal idiosomal striations are devoid of tubercles or verrucosities, the full set of the gnathosomal and idiosomal setae, excluding h1, is present (setae 3a absent in some Harpirhynchus ), setae h2 are slightly thickened, whip-like, legs I and II are inserted laterally with well developed paired claws and ciliated empodium, legs III and IV are present, moderately developed. They differ from each other by the following character states. In females of Crassacarus gen. nov., the idiosoma is wider than long or length and width are subequal (vs. longer than wide in Harpirhynchus ), setae d of genua I and II are absent (vs. present; absent only in some specimens of H. nidulans ), setae 1a and 3a are distinctly shorter than 1c (vs. subequal to 1c), setae 1a are situated significantly posterior to leg I insertions and close to setae 3a (vs. close to level of leg I insertions and distinctly separated from 3a (if present)).

Remarks. Crassacarus cylindripalpus ( Fritsch, 1954) comb. nov. is transferred from the subgenus Pseudoharpirhynchus of the genus Harpirhynchus (see remarks to the genus Harpirhynchus ).