Hoplandrothrips hylaius, Mound, Laurence A. & Tree, Desley J., 2013

Mound, Laurence A. & Tree, Desley J., 2013, Fungus-feeding thrips from Australia in the worldwide genus Hoplandrothrips (Thysanoptera, Phlaeothripinae), Zootaxa 3700 (3), pp. 476-494 : 487-488

Hoplandrothrips hylaius sp.n.

( Figs 17–21 )

Male macroptera. Body bicoloured, light brown and yellow; antennal segment III mainly yellow, IV–VI light brown with base yellow; pronotum yellow browner medially, head light brown with pair of longitudinal submarginal yellow areas; pterothorax brown, abdomen variably brown with II–VII yellow submedially; mid and hind legs light brown, tarsi yellow; fore wing uniformly but weakly shaded with base slightly darker; major setae dark on head and pronotum, pale on tergites II–VIII.

Head longer than wide, wider behind large eyes then narrowing to basal constriction ( Figs 17, 18 ); dorsal surface reticulate; cheeks with several pairs of prominent setae including one stout pair in basal third particularly in large males; postocular setae placed laterally, longer than eye in large males; maxillary stylets retracted anterior to postocular setae, close together medially; mouth cone pointed, not extending across prosternum. Antennal segment III with 3 sensoria, IV with 4 sensoria; VII clearly pedicellate, VIII narrowed to base.

Pronotum with reticulation only near posterior margin; large male with strong longitudinal apodeme ( Fig. 20 ); am setae acute, no larger than discal setae, remaining 4 pairs of setae capitate, aa of large male longer than head width; basantra absent, chitinous islets large; large males with anterior margin of mesoeusternum narrow and mesopresternum small and boat-shaped; small males with mesopresternum transverse across wide mesoeusternal margin; sternopleural sutures well-developed. Large males with fore femora swollen, inner apex without tubercles; fore tibiae stout, inner margin with one sub-apical tubercle; fore tarsal tooth longer than tarsal width. Small males with fore femora and tibiae slender, tarsal tooth shorter than tarsal width. Mesonotal lateral setae elongate, capitate. Anterior half of metanotum weakly reticulate ( Fig. 19 ), with pair of longitudinal ridges in large males; median setae usually acute, arising on anterior half of sclerite, with 2–5 pairs of discal setae anteromedially. Fore wings not quite parallel sided, very weakly constricted medially and toward apex; sub-basal setae S1 and S2 capitate, S3 long and pointed; with about 20 duplicated cilia.

Pelta elongate bell-shaped, broadly flared at base; tergites II–VII with 2 pairs of wing retaining setae, also 1–3 pairs of variably curved discal setae laterally, lateral setae S1 and S2 capitate; tergite IX setae S1 weakly capitate, S2 blunt, intermediate seta not elongate. Sternite V with 14–18 discal setae; II–V with pair of specialised reticulate areas anterolateral to discal setae in many specimens ( Fig. 21 ); VIII with rectangular pore plate medially.

Measurements (holotype male in microns, with small male in parentheses). Body length 3700 (2400). Head, length 375 (300); width 250 (200); po setae 140 (65). Pronotal setae length: am 20 (10), aa 210 (65), ml 115 (35), epim 110 (70), pa 50 (25). Fore wing length 1400 (1000). Tergite IX setae: S1 85 (75); S2 60 (50); S3 150 (140). Tube length 200 (170). Antennal segments III–VIII length 105 (80), 115 (85), 100 (80), 65 (65), 55 (50), 45 (40).

Female macroptera. Larger than, but similar in structure to, small males; metanotal median setae capitate; tergite IX setae S1 and S2 capitate.

Measurements (paratype female in microns). Body length 3400. Head length 360; width 250; po setae 80. Pronotal setae length: am 30, aa 55, ml 50, epim 90, pa 55. Fore wing length 1300. Tergite IX setae: S1 100; S2 90; S3 160. Tube length 230. Antennal segments III–VIII length 105, 105, 95, 75, 55, 45.

Larva II. Yellow, with large numbers of irregular bright red spots, some of which coalesce.

Specimens examined. Holotype male (on slide with smallest male paratype), New South Wales, Mt Dromedary summit, from dead branches in rainforest, 25.xii.2010 (LAM 5411–13).

Paratypes: New South Wales, 8 males, 7 females taken with holotype and larvae; Chichester Forest at 900m, 4 males, 3 females, also larvae from old dead branch of Nothofagus moorei , 24.xii.2000. Queensland, Lamington, 1 female by insecticide fogging of Nothofagus moorei , 10.xii.1990. South Australia, Adelaide Hills, Waterfall Gulley, 1 female from dead leaves, 22.x.2004. Tasmania, Mt Wellington, 1 male from dead Eucalyptus leaves, 27.xi.2012; 17 Mile Plain, 1 female from gum nuts, 10.iii.2010; 6 males, 5 females with no host data, from various sites between Launceston, Huon Valley and Bruny Island.

Comments. This species is widely distributed in wetter areas of the eastern forests of Australia. The differences in structure between large and small males are impressive, with the cheek setae and head shape, and the length of the pronotal anteroangular setae exhibiting positive allometry. Similarly, the differences are remarkable between females and large males in the structure of the mesopresternum and mesoeusternal anterior margin, and these differences are potentially confusing. The significance of the specialised areas of reticulation on the sternites of large males remains unclear. Similar structures are found in several species discussed here, but are particularly typical of species placed in the worldwide genus Holothrips (see Okajima 2006).

Figures

FIGURES 15 – 21. Hoplandrothrips from Australia. hemiflavus sp. n. 15 – 16: (15) head & pronotum; (16) Meso & metanotum, pelta & tergite II. hylaius sp. n. 17 – 21: (17) holotype head; (18) small male head & pronotum; (19) holotype meso & metanotum and pelta; (20) holotype pronotum; (21) male sternite V.