Litotetothrips symplocosae, Mound & Tree, 2022

Mound, Laurence A. & Tree, Desley J., 2022, Phlaeothripidae (Thysanoptera) diversity in Australia, with three new generic records and two new species, Zootaxa 5104 (2), pp. 291-296 : 292

Litotetothrips symplocosae sp.n.

( Figs 1–3 )

Female macroptera. Body and legs brown, head and tube darkest, fore tibiae brownish yellow distally, fore tarsi yellow but mid and hind tarsi brown; antennal segment II yellow on distal half, III–IV clear yellow, V yellow with extreme apex weakly shaded, VI yellow on basal two-thirds, VII–VIII brown ( Fig. 3 ); fore wings brown around basal setae, then pale but with weak shading extending to apical third paler but margins not shaded; major setae on head and body very weakly shaded. Head as long as wide ( Fig. 1 ), slightly constricted just behind eyes, genae narrowed to basal neck without setae; vertex with weak transverse reticulate sculpture; compound eyes with one posterolateral facet slightly enlarged; stylets retracted almost to postocular setae and about one third of head width apart; postocular setae blunt at apex, slightly shorter than dorsal eye length. Antennal segment III with 1 sense cone, IV with 3 sense cones; VII constricted to basal neck ( Fig. 3 ). Pronotum with weak sculpture lines only at anterior and posterior, smooth medially; five pairs of well-developed setae, major setae blunt to weakly capitate; notopleural sutures incomplete. Mesonotal lateral setae small and blunt at apex; metanotal median setae very small and acute; metanotum weakly reticulate medially. Prosternal ferna large, widely separated; mesopresternum reduced to three weak sclerites; metathoracic sternopleural sutures not developed. Fore wing sub-basal setae blunt to weakly capitate; about 14 duplicated cilia present. Fore tarsus with no tooth. Pelta broadly triangular, without campaniform sensilla ( Fig. 2 ); tergite lateral setae blunt to weakly capitate; tergite IX setae S1 and S2 long and pointed; anal setae shorter than tube.

Measurements (holotype female in microns). Body length 2600. Head, length 225; width behind eyes 235; po setae 85. Pronotum, length 175; width 325; major setae – am 45, aa 50, ml 65, epim 100, pa 95. Fore wing, length 950; sub-basal setae 50, 55, 70. Mesonotal lateral setae 35; metanotal median setae 15. Tergite IX setae 260, 250, 200. Tube length 250. Antennal segments III–VIII length 70, 65, 65, 70, 55, 45.

Male macroptera. Similar to female in colour and structure; tergite IX setae S2 short and stout on left side but on right side long and slender with S3 short and stout; sternite VIII without pore plate.

Specimens studied. Holotype female, Queensland, Eubangee [= Eubenagee ] Swamp , 5km South of Cairns, from young rolled leaves of Symplocos cochinchinensis [ Symplocaceae ], 17.viii.2006, (DJ Tree), in ANIC.

Paratypes: 7 females, 1 male taken with holotype (in ANIC & QDPC) .

Comments. The problems of distinguishing Litotetothrips from Thlibothrips were discussed recently ( Mound & Tree 2021). These are two of the smaller Phlaeothripinae genera that were erected, but never distinguished, by Priesner for some Asian leaf-feeding species. This new species emphasises these problems, as it has character states intermediate between the two genera as currently interpreted. However, as stated in the previous publication, it is not possible to synonymise these two genera without further study of the original specimens of the two type species. The head of this new species is as long as wide, a condition considered diagnostic for Litotetothrips (in contrast to 1.1 times as long as wide in Thlibothrips ), and the maxillary stylets are retracted almost, but not quite, to the level of the postocular setae. The new species is very similar to L. tareei that remains known only from two males taken on the central coast of New South Wales. From that species, L. symplocosae differs in having antennal segment VII clearly constricted to a basal neck, antennal segments III–V clear yellow with only the apex of V weakly shaded and segment VI clear yellow in the basal two-thirds; pronotal notopleural sutures incomplete, mesopresternum divided into three very small sclerites, and the pelta without campaniform sensilla. The chaetotaxy of tergite IX in the species of Litotetothrips seems to be unstable occasionally, with setal pair S2 asymmetric and reduced in length in some individuals.

Figures

FIGURES 1‒12. Australian Phlaeothripinae. Litotetothrips symplocosae sp.n. 1‒3: (1) Head & pronotum; (2) Metanotum & pelta; (3) Antennal segments II‒VIII. Ponticulothrips mudloi sp.n. 4‒7 (male): (4) Antennal segments II‒VIII; (5) Fore tarsus; (6) Head; (7) Pelta. Trichinothrips breviceps 8‒9: (8) Antenna; (9) Head & thorax. Tylothrips osborni 10‒12: (10) Head; (11) Metathoracic ventro-lateral seta; (12) Pronotum.