Ecacleistothrips glorious, Mound, Laurence A., 2007

Mound, Laurence A., 2007, New Australian spore-feeding Thysanoptera (Phlaeothripidae: Idolothripinae), Zootaxa 1604, pp. 53-68 : 55-57

Ecacleistothrips glorious sp.n.

( Figs 1–7 )

Macropterous female. Body and legs brown, tube darkest, tarsi paler, antennal segment III basal 0.6 yellowish brown; major setae pale; forewing light brown with base pale. Head longer than wide; median setae on vertex about 0.2, lateral postocular setae about 0.5, as long as major postocular setae; preocellar setae longer than first antennal segment. Sensoria on antennal segments III–IV shorter than apical width of these segments. Pronotum reticulate except posteromedially; mesonotum reticulate, lateral setae long; metanotum reticulate, median setal pair long. Forewing marginal cilia strongly rugose, about 52 smooth duplicated cilia; 4 prominent sub-basal setae present. Abdominal tergites with lateral setae longer than median length of each tergite; major setae on sternites arise submarginally.

Measurements of holotype female in microns. Body length 7800. Head, length 700; width 420; preocellar setae 170; postocular setae 40, 300, 140. Pronotum, length 340; width 670; major setae am 40, aa 120, ml 300, epim 400, pa 400. Metanotum median setae 400. Forewing, length 3000; distal width 600; terminal cilia 100; sub-basal setae 90, 210, 230. Tergite III setae, median 60; wing-retaining 150; lateral marginal 600; posteroangular 600. Tergite IX setae S1 950, S2 950. Tube, length 1400; anal setae 150. Antennal segments III–VIII length, 350, 240, 210, 180, 140, 90.

Apterous female. Similar to macroptera except: head less slender, eyes narrower ventrally, midvertex setae 0.5 as long as major postocular setae. Mesonotal lateral setae very small. Metanotum transverse, with three long pairs setae medially, laterally and anterolaterally (this pair is variable). Pelta D-shaped with lateral wings scarcely visible; tergites II–VI with wing-retaining setae and tergal median setae long and straight.

Measurements of paratype female aptera in microns. Body length 6700. Head, length 640; width 420; preocellar setae 130; postocular setae 130, 340, 140. Pronotum, length 320; width 660; major setae am 60, aa 130, ml 320, epim 400, pa 350. Metanotum median setae 380. Tergite III setae, median 350; wing-retaining 300; lateral marginal 600; posteroangular 550. Tube length 1200

Apterous male. Similar to apterous female except: head broader, ocelli reduced, midvertex setae as long as major postocular setae; ventrally with a stout horn arising between anterior pair of interocular setae, also one pair of stout tubercles present ventrolaterally just anterior to clypeal suture. Pronotum massive, not reticulate but with stout median apodeme, am setae long and arising submarginally; ferna occupying most of prosternum. Metanotum strongly transverse, median setae long, lateral setae short and thorn-like. Pelta eroded antero-posteriorly but completely transverse between spiracles across tergite, bearing two pairs of major setae; tergites II–VI with median and wing-retaining setae stout and thorn-like, posteroangulars long; tube relatively short.

Measurements of paratype male aptera in microns. Body length 6350. Head, length 550; width 400; preocellar setae 250; postocular setae 330, 350, 220. Pronotum, length 650; width 950; major setae am 240, aa 350, ml 400, epim 330, pa 420. Metanotum median setae 400. Tergite IV setae, median 75; wing-retaining 75; lateral marginal 450; posteroangular 450. Tube length 950.

Material studied. Holotype macropterous female, Queensland, Brisbane Forest Park, Mt Glorious , from rotting branch on ground in rainforest, 9.iii.2006 (LAM 4861).

Paratypes: 2 female macropterae, 3 female apterae, 1 male aptera, all taken at same locality with holotype and several larvae.

Comments. The adults and larvae of this species were collected from 4cm diameter, soft and decayed, branches on the forest floor in rainforest. This habitat is unusual amongst fungus-feeding Phlaeothripidae , as thrips are usually found on branches and twigs that are only recently dead. Presumably the fungal species on which thrips usually feed are associated with the early stages of fungal decay, in contrast to the wet, rotten wood on which E. glorious was living. The gut contents of adults and larvae included closely packed masses of spores of a species of Xylaria (Ascomycota) .

The variation in form of the pelta in this new species, from the median D-shaped sclerite of winged individuals ( Fig. 6 ) to the irregular transverse sclerite of the wingless male ( Fig. 7 ), is particularly interesting. Bhatti (1994, 1995) indicated that the plesiotypic condition of the pelta, the first abdominal tergite of Phlaeothripidae , must have been fully transverse. Although on theoretical grounds this might be correct, in all present day taxa with a transverse pelta the condition is associated with wing loss. As in the present species, the transverse pelta of such apterous species represents a highly derived character state that has arisen in several unrelated lineages of this family. A further interesting character state is the extreme shortness and rugosity of the cilia around the apex of the forewing. The shortness of these cilia is presumably related aerodynamically to the exceptional forewing width. Similar short terminal cilia occur on the unusually broad forewings of species of Xaniothrips Mound , although Bhatti (1994: 121) used this character state to support his recognition of a family, Xaniothripidae. A further recurrent character that is presumably associated with body size and male behaviour rather than phylogenetic relationships, is the presence of a stout horn ventrally on the anterior margin of the head in the male. A similar horn is known in the New Zealand species, Hoplothrips anobii Mound & Walker , as well as in species of Sophiothrips and Zaxenothrips , and is possibly associated with male/male competition.

Figures

FIGURES 1 – 7. Ecacleistothrips glorious. 1 & 2, Female holotype; 3, Female prosternites; 4, Male; 5, Holotype antenna;