Scirtothrips gymnos, Mound & Wells, 2023

Mound, Laurence A. & Wells, Alice, 2023, Endemism among Lord Howe IslandThysanoptera, with new species of Baenothrips (Phlaeothripidae) and Scirtothrips (Thripidae), Zootaxa 5228 (1), pp. 81-91 : 87-89

Scirtothrips gymnos sp.n.

( Figs 16, 21, 22 )

Female macroptera. Body colour yellow with small amount of faintly red internal pigment; fore wings uniformly light brown with darker major setae; antennal segments I–III much paler than IV-VIII. Antennae 8-segmented, forked sense cone on III and IV not reaching more than one-third the length of succeeding segment; inner sense cone on VI extends almost to apex of VIII. Head with ocellar triangle with weak reticulate sculpture lines ( Fig. 16 ); ocellar setae pair III weak and shorter than a posterior ocellus, just in front of the tangent between the hind margins of hind ocelli; postocular setae I–II shorter than ocellar setae pair III, postocular setae III not developed. Pronotum transversely reticulate, distance between transverse striae commonly more than twice the diameter of a discal seta base ( Fig. 16 ); 4 pairs of posteromarginal setae, S2 shorter than diameter of antennal segment II, S4 minute. Metanotum reticulate, median setae short and arising posterior to anterior margin but varying in position. Fore wing second vein with 4 setae; first vein with group of 3 setae sub-basally, then about 4 setae, and 3–5 setae on distal half; clavus with 4 veinal and one discal setae; distal posteromarginal cilia almost straight but with apical thirds weakly wavy. Abdominal tergites II–VII with setae S1 small and arising slightly further apart than their length ( Fig. 22 ); lateral thirds with 3 discal setae, but transverse sculpture lines lacking any prominent microtrichia although posterior margin laterally with comb ( Figs 21, 22 ); VIII with S1 setae long, posteromarginal comb long but no discal microtrichia medially ( Fig. 21 ); IX–X with no discal microtrichia. Sternites with lateral microtrichial rows either absent or scarcely extending mesad of marginal setal pair S3.

Measurements (holotype female in microns). Distended body length 900. Head, length 55; width across eyes 120; ocellar setae III 12. Pronotum, length 80, width 130; posteromarginal setae S1 12, S2 30, S3 12, S4 8. Metanotum median setae?, submedian setae 25. Fore wing, length 500. Tergite median setae length, on III 10, on VII 15, on VIII 40. Antennal segments III–VIII length 35, 32, 30, 40, 8, 8.

Male: Not known.

Specimens studied. Holotype female, Australia, Lord Howe Island , Soldiers Creek, from ferns, 25.xii.2001 (LAM 4084) in ANIC.

Paratypes: 6 females taken with holotype.

Comments. This species is unique among member of the genus Scirtothrips in lacking rows of microtrichia on the tergites, and it also has very few such rows on the sternites. The other character states are typical of this genus, and the sculpture on the pronotum suggests that this species is closely related to cyatheae describe above.

Figures

FIGURES 14–22. Scirtothrips species. Head & pronotum 14–16: (14) albomaculatus; (15) cyatheae; (16) gymnos. Female cyatheae 17–20: (17) Metanotum; (18) Tergites I–III; (19) Tergites VI–X; (20) Sternites VI–VIII. Female gymnos 21–22: (21) Tergites IV–VIII; (22) Tergites V–VI.