Eotetranychus queenslandicus Manson 1967
Creators: name: Zhang, Lanni
Publisher: name: Zenodo
Year: 2017
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Arachnida
Prostigmata
Tetranychidae
Eotetranychus
Eotetranychus queenslandicus

description: Eotetranychus queenslandicus Manson, 1967
Figures 46–59.
Eotetranychus queenslandicus Manson, 1967: 671.
Eotetranychus sexmaculatus.— Waite, 1991: 427 (misidentification). Eotetranychus sexmaculatus.— Learmonth, 2016: 1 (misidentification).
Diagnosis. Both sexes: Peritreme terminating in small hook; dorsal setae with numerous small barbs, all dorsocentral setae (c1, d1, e1, f1) much longer than distance to base of respective dorsocentral seta in next row. Tibiae III–IV with transverse striae; tarsi I–IV with transverse striae dorsoproximally and longitudinal striae distally; ventral tarsal striae pattern with mostly longitudinal striae and two bands of transverse striae, one mesally and one proximally. Female: Pregenital striae longitudinal; genital striae longitudinal in anterior half, transverse in posterior half. Leg setal counts: trochanters 1, 1, 1, 1; femora 10, 7, 4, 3; genua 5, 5, 4, 4; tibiae 10 (1), 8, 6, 7; tarsi 19 (3+3), 16 (2+3), 11 (1+0), 11 (1+0). Male: Aedeagus directed posteriorly and almost linear and without medial curve, tapering to blunt point, without head, tip not deflexed ventrally.
Type material examined. 2 ♂ paratypes, 6 ♀ paratypes, E. queenslandicus, Australia, ex Codiaeum sp. (Euphorbiaceae), Queensland, 28.iv.1964, J.H. Strickett. P.Q. A607. (USNM). All specimens on same slide. No specimen is marked as the holotype, but as the slide is coloured red, one specimen could be the holotype (we assume it is the laterally mounted male).
Non-type material examined (all misidentified as E. sexmaculatus). Australia. 11 ♀, 7 ♂, ex avocado leaves, Birdwood Nursery, Woombye, Queensland, 4.ix.1986, G. Waite, D. Smith. 3 ♀, 4 ♂, ex grape Vitis vinifera (Vitaceae), Western Australia, 6.vi.2006, S. Learmonth. 2 ♀, 2 ♂, ex V. vinifera, Resolution Vineyard, 4 Sunnybanks Rd, Middleton, Tasmania, 17.iii.2015, P. Brown. All in QM.
Comparative material examined, E. sexmaculatus. United States of America. 2 ♀, ex citrus fruit (Rutaceae), California, 1948, P. De Bach, Lot 51–2406. 1 ♀, 1 ♂, ex avocado (Lauraceae), Morrow [Morro] Bay, California, 3– iv.1986, J.M. McMurtry. Possible misidentification: 1 ♂, ex Citrus sp. (Rutaceae), Capistrano, California, 7.ix.1951, L.R. Jeppson, Lot 51–10088. All in USNM.
Remarks. Eotetranychus queenslandicus is almost identical to what is currently accepted to be E. sexmaculatus, differing only in the shape of the aedeagus. Initially, we considered synonymising these species, but published descriptions of the aedeagus of E. sexmaculatus differ considerably (Figs 42–44), and unfortunately Riley (1890) did not provide any details of the male. The illustrations of North American specimens by McGregor (1950), Pritchard & Baker (1955), Jeppson et al. (1975) and Baker & Tuttle (1994) show E. sexmaculatus with a serpentine aedeagus: i.e., it curves medially, then again at its tip (Figs 42–43). However, the only other drawing of the aedeagus of E. sexmaculatus is provided by Gupta & Gupta (1994) of specimens from India (Fig. 44), and does not match the earlier illustrations. Based on this illustration, the morphology of these Indian specimens appears closer to that of E. asiaticus Ehara, 1966 (Fig. 45) and E. queenslandicus (Figs 47–50), and the specimens identified as E. sexmaculatus in Australia (Figs 51–59). Our considerations of synonymising E. queenslandicus and E. sexmaculatus mirrors the taxonomic history of E. asiaticus, which was synonymised under E. sexmaculatus by Ehara (1973), but later considered separate again (Ehara, 1993, 1996; Ehara & Gotoh, 2009). This decision was based solely on aedeagal morphology.
The aedeagus of E. queenslandicus is very similar to that of E. asiaticus, and the former may in fact be a junior synonym of the latter. However, we refrain from making this synonymy as we have not examined any types of E. asiaticus, and because there are several species involved in this complex of species further synonymies may be required. For instance, Eotetranychus lewisi (McGregor, 1950), also found on citrus in the USA, and Eotetranychus talisiae (Hirst, 1920), are morphologically similar to E. sexmaculatus and to E. asiaticus, respectively. In addition, it should be noted that there are 13 species of Eotetranychus known from Citrus, some of which are difficult to separate from each other—such as E. sexmaculatus and E. lewisi. A further complicating factor is that one of the specimens we examined, which had been examined by Pritchard and Baker (1955) and identified as E. sexmaculatus, is not this species. In summary, the multiple species of Eotetranychus on citrus, misidentifications within the examined material of Pritchard & Baker (1955), coupled with the fact that McGregor (1950) and Pritchard & Baker (1955) did not examine Riley’s (1890) type specimens of E. sexmaculatus, means that the current concept of E. sexmaculatus may not match that of Riley (1890).
A further outcome of these observations is that E. sexmaculatus is no longer considered present in Australia. All specimens we examined, including those from the original 1986 record, are here considered to be E. queenslandicus.
description: Published as part of Zhang, Lanni, 2017, A new Australian species of Eotetranychus (Acari: Tetranychidae) from buck spinifex Triodia mitchelli (Poaceae), intraspecific variation in Eotetranychus, and the synonymy of Platytetranychus with Eotetranychus, pp. 491-517 in Zootaxa 4324 (3) on pages 508-509, DOI: 10.11646/zootaxa.4324.3.5, http://zenodo.org/record/998438