Pharothrips hynnis, Mound & Wells, 2020

Mound, Laurence A. & Wells, Alice, 2020, Two new monobasic thrips genera for a gall-inducing species and its kleptoparasite (Thysanoptera, Phlaeothripinae), Zootaxa 4759 (3), pp. 421-426 : 424-426

Pharothrips hynnis sp.n.

( Figs 8–17 )

Female macroptera. With generic character states as indicated above. Body brown; tarsi, fore tibiae and apices of femora yellow; antennal segment III yellow, also apex of II, IV–VIII increasingly darker brown; fore wing shaded on distal half; setae all pale. Head with few and irregular sculpture markings; posterior ocelli almost in contact with curved inner margin of compound eyes; antennal segments III–VII evenly tapering to base ( Fig. 17 ), sense cones not elongate; pronotum without sculpture, setae am, aa and ml not distinguished from discal setae; fore tibia sharply angulate posterolaterally, inner apex ventrally with strongly recurved tooth; fore wing with about 12 duplicated cilia; tergal wing-retaining setae weakly sigmoid; tube slightly convex in anterior third, tapering on posterior third.

Measurements (holotype female, in microns). Body length 3600. Head, length 480; po setae 75. Pronotum, length 480; width 420; prothorax width 500; setae, epim 25, pa 35. Fore wing length 1550; width 160; sub-basal setae 20. Tergite IX setae S1 215; S2 225; S3 200. Tube length 270. Antennal segments III–VIII length 85, 80, 80, 80, 75, 38.

Male microptera. Similar to female but smaller; head shorter, ventrally in association with tentorial pits a transverse ridge or pair of small tubercles, posterior to this a recessed area with about 20 small setae ( Fig. 11 ); antennal segments IV–VII each with narrowed pedicel ( Fig. 16 ); pronotum less elongate than in female, particularly in small male; prosternal ferna with convex inner margins; meso and metanotum almost without sculpture, fore wing lobe shorter than thorax width; tergite IX setae S2 variable from as long as S1 to half as long, S3 shorter than S2.

Measurements (paratype male, in microns). Body length 2100. Head, length 270; po setae 70. Pronotum, length 230; width 270; prothorax width 320. Fore wing length 170. Tergite IX setae S1 185; S2 100; S3 100. Tube length 180. Antennal segments III–VIII length 85, 80, 80, 80, 75, 38.

Specimens studied. Holotype female macroptera, New South Wales, 20km south of Taree, Black Head , from marginal leaf-roll gall on Drypetes deplanchei , 14.iv.2002 (LAM 4148).

Paratypes: 10 females, 2 males taken with holotype; 25km north of Taree , 12 females 4 males from marginal leaf-roll galls on Drypetes deplanchei , 27.xii.2006; Queensland, Brisbane, Mt Nebo , 4 females, 2 males from marginal leaf-roll galls on Drypetes deplanchei , 9.vii.2002.

Comments. The small tubercles ventrally between the eyes are similar to structures found in this position on males of various unrelated, fungus-feeding, Phlaeothripinae , but they are not previously recorded from females. The elongate, bifurcate tubercle arising ventrally from near the tentorial pits is unique amongst Phlaeothripinae of either sex. This tubercle must be expensive in terms of developmental energetics, and the objective of this investment is unclear. One possibility is that the tubercle might be used to lift a leaf margin ( Fig. 1 ) of a closely sealed gall of Drypetothrips korykis and thus facilitate invasion. There is no evidence that this thrips is predatory on its host, nor is there any evidence that it can itself induce a gall on a Drypetes leaf. It appears to invade a pre-existing gall and breed within the gall cavity, feeding on the leaf tissues. Of 26 galls examined at a site near Taree, nine healthy green galls contained only D. korykis adults and larvae, 13 rather older slightly distorted galls contained only Ph. hynnis adults and larvae, and four contained individuals of both species. From the galls found at Mt Nebo, 18 D. korykis and six Ph. hynnis were extracted.

Figures

FIGURES 8–17. Pharothrips hynnis gen et sp. n. (8) female head and thorax ventral; (9) female head ventral; (10) female head lateral; (11) male head ventral; (12) female pronotum; (13) female prosternum; (14) female pelta and tergite I; (15) female tergite IX and tube; (16) male antenna; (17) female antenna.

FIGURES 1–7. Drypetothrips korykis gen et sp. n. and galls. (1) Drypetes deplanchei leaf margin galls; (2) holotype head and pronotum; (3) meso and metanotum; (4) antenna; (5) prosternites; (6) tergite IX and tube; (7) pelta and tergites II–IV.