Odontacarus robbinsi Loomis and Spath, 1969

Stekolnikov, Alexandr A., Capek, Miroslav & Literák, Ivan, 2022, New species and records of chiggers (Acariformes: Trombiculidae) from birds of the Neotropics, Zootaxa 5141 (6), pp. 501-552 : 544-546

Odontacarus robbinsi Loomis and Spath, 1969

( Fig. 27 )

Odontacarus robbinsi Loomis and Spath, 1969: 187 , fig. 1.

Odontacarus (Odontacarus) robbinsi: Goff & Loomis 1977: 373 ; Hoffmann 1990: 180, fig. 148.

Diagnosis. SIF = 7B-B-3-2111.1000; fsp = 6.6.6; fCx = 2.1.1; fSt = 0.2; fPp = B/B/BNN; fSc: PL> AM> AL; Ip = 1238–1283; fD = 2H-[5-8]-8-10-8-6(7)-5; DS = 52–53; V = 49; NDV = 101–102. Cheliceral blade with 5 dorsal teeth; stigmata situated at base of gnathosoma, tracheae extend to caudal third of idiosoma; scutum nearly pentagonal, with pointed nasus on anterior margin and angulate posterior margin, with dense puncta; two AM at level of AL; sensilla flagelliform, with ca. 6 long branches in distal half, far anterior to level of PL (PSB—P-PL = 7–11 µm); onychotriches present; parasubterminala (z) branched; f 1 proximal to S 1, f 2 proximal to S 2; microgenuala II present; mastitarsala ciliated. Standard measurements of two examined specimens (ZIN 9004 and ZIN 9037): AW 64, 68; PW 84, 86; SB 27, 27; ASB 28, 35; PSB 29, 29; SD 57, 64; P-PL 18, 22; AA 12, 13; NL 16, 18; NW 8, 9; AP 35, 36; AM 39, 37; AL 36, 34; PL 55, 58; S -, 50; H 52, 56; D min 32, 32; D max 50, 41; V min 23, 25; V max 35, 40; pa 452, 430; pm 380, 371; pp 452, 437; Ip 1283, 1238; DS 52, 53; V 49, 49; NDV 101, 102; TaIIIL 119, 110; TaIIIW 16, 19.

Distribution. Mexico ( Loomis & Spath 1969) and Paraguay (this study).

Hosts . Sceloporus zosteromus Cope (= S. magister zosteromus ), S. licki Van Denburgh (= S. orcutti licki ), Urosaurus nigricaudus (Cope) ( Squamata : Phrynosomatidae ) ( Loomis & Spath 1969).

New host records: Coryphistera alaudina and Zonotrichia capensis .

Material examined. One larva ( ZIN 9004 ) ex C. alaudina No PG 303, PARAGUAY: Teniente Agripino Enciso Nat. Park, 2 September 2012; 1 larva ( ZIN 9037 ) ex Z. capensis, Tres Gigantes Biological Station , 6 September 2012 .

Remarks. According to the original description, this species has 4 dorsal and 3 ventral teeth on the cheliceral blade. We did not observe ventral teeth, but recorded 5 dorsal teeth; insufficient sample size does not allow estimation of the reliability of this difference. The difference in the dorsal setal formula of idiosoma (10-8-6-10-8+27, according to the original description) was caused most probably by differently traced borders between setal rows; however, the total number of setae in our specimens is almost the same (NDV = 101–102 vs. 103). Branched parasubterminala (z) of this species was evidently treated by the authors of original description as a non-specialized seta and thus was omitted. We should note that there is no way to distinguish “branched subterminala” from “subterminala replaced with a non-specialized branched seta” by a morphological examination. Finally, our measurements of the scutum and setae are in good agreement with those given in the original description.

Figures

FIGURE 27. Odontacarus robbinsi Loomis and Spath, 1969, specimen ZIN 9004 (one leg II lost). A—general view, B—dorsal aspect of idiosoma, C—scutum, D—ventral aspect of idiosoma. Scale bars: 100 µm (A), 50 µm (B–D).