Heligmothrips exallus, Mound & Tree & Wells, 2022

Mound, Laurence A., Tree, Desley J. & Wells, Alice, 2022, Convoluted maxillary stylets among Australian Thysanoptera Phlaeothripinae associated mainly with Casuarinaceae trees, Zootaxa 5190 (3), pp. 301-332 : 321

Heligmothrips exallus sp.n.

( Figs 56 , 62, 64, 67 )

Female macroptera. Body light brown, head paler posteromedially, tube dark brown; antennal segment II paler at apex, III paler basally, IV–VIII uniformly brown; all tibiae paler than brown femora, tarsi yellow; male setae pale; fore wings very weakly shaded. With the character states given in the generic diagnosis, except as follows: head longer than wide ( Fig. 56 ), vertex with little or no sculpture, genae without prominent setae; postocular setae capitate, extending to hind margin of eyes; eyes smaller ventrally than dorsally; hind ocelli close to eyes; maxillary stylets cross over at level of eyes, then re-cross through very sharp angle at posterior margin of head before producing one large circle posterolaterally and entering mouth cone; mouth cone long and pointed.Antennal segments not elongate, III less than twice as long as wide with basal stem bearing small irregular rings ( Fig. 67 ). Pronotum elongate, only slightly wider than long but much narrower than prothorax ( Fig. 56 ); major setae long, pale and capitate. Mesonotal lateral setae capitate. Metanotum very weakly reticulate, median setae finely pointed ( Fig. 62 ). Prosternal ferna very wide apart, mesopresternum of two lateral triangles only weakly linked medially ( Fig. 64 ). Fore tarsal tooth almost as long as tarsal width. Fore wing with 8 duplicated cilia. Pelta elongate bell-shaped ( Fig. 62 ); tergites II–VII each with 2 pairs of wing-retaining setae of which the anterior pair is small on each tergite; tergite IX setae long and capitate; tube shorter than head.

Measurements. Body length 2100. Head, length 175; width medially 140; po setae 40. Pronotum, length 200; width 230; prothorax width 300; major setae – am 25, aa 50, ml 45, epim 70, pa 30. Fore wing length 700; sub-basal setae 35. Tergite IX setae S1 105, S2 95. Tube, basal width 75, length 135. Antennal segments III–VIII length 55, 48, 50, 45, 45, 25.

Specimens studied. Holotype female macroptera, Queensland, Carnarvon Station , from woodland barkspray, 16.x.2014.

Comments. This species shares many character states with other species in the genus Heligmothrips , but it is clearly aberrant within the genus in its more elongate shape, relatively short antennae and weakly sculptured surface.

Figures

FIGURES 51–59. Heligmothrips species heads and stylets. (51) brevidens; (52) erinaceus; (53) gracilior; (54) eiletus; (55) eiletus larva; (56) exallus; (57) macropus; (58) narrabri; (59) xantoskelus.

FIGURES 60–68. Heligmothrips species thorax and antenna. (60) eiletus; (61) narrabri; (62) exallus; (63) xanthoskelus; (64) exallus; (65) xanthoskelus; (66) narrabri; (67) exallus antenna; (68) macropus pronotum.