Nazonothrips, Okajima & Masumoto, 2022

Okajima, Shuji & Masumoto, Masami, 2022, Enigmatic male dimorphism in the Phlaeothripinae (Thysanoptera, Phlaeothripidae), with description of a new genus and species, Zootaxa 5134 (4), pp. 561-568 : 562-564

Nazonothrips gen. n.

Small species. Head short, at least wider than long in macropterae ( Fig. 8 ), small and wider to a little longer in apterae ( Figs 14–16 , 21–22 ); postocular setae situated laterally. Eyes and ocelli large in macropterae; eyes reduced and ocelli absent in apterae. Antennae ( Fig. 9 ) typical of Plectrothripini ; 8-segmented; segment II with campaniform sensillum at base (often near middle); segments III–VIII with weak transverse lines of sculpture; segment VIII long and spindle shaped; sense-cones somewhat stout in macropterae, smaller in apterae. Mouth-cone rounded at apex; maxillary stylets short and V-shaped, not retracted into head capsule; maxillary bridge absent. Pronotal shield ( Figs 8 , 14–16 , 21–22 ) with two pairs of long setae, anteroangulars and posteroangulars; epimeral setae developed; episternum reduced to a slender plate. Notopleural suture incomplete to nearly complete. Basantra absent; ferna largely developed ( Figs 11 , 17–18 , 23 ). Mesopresternum absent; mesoeusternum eroded. Mesonotum without long lateral setae ( Fig. 10 ), strongly eroded in apterae ( Figs 14–16 , 21–22 ). Fore tarsus with a tooth in both sexes ( Figs 19–20 , 24 ); mid and hind tibiae with no stout seta. Pelta broadly hat-shaped ( Figs 10 , 14–16 , 21 ), eroded and weak. Abdominal tergites simple, without curved wing retaining setae even in macropterae ( Fig. 12 ); tergite II nearly complete, very weakly eroded laterally; intermediate tergites with two pairs of setae (S1 and S2) posterolaterally; tergite IX with posteromarginal setae (S1 and S2) longer than tube. Abdominal sternites without pore or reticulate areas. Tube ( Fig. 13 ) shorter than head and tapering; terminal setae shorter than tube.

Type species. Nazonothrips toshifumii sp. n.

Comments. The character states of Nazonothrips , especially the antennae, are very similar to those of the genus Plectrothrips and its relatives ( Okajima, 1981). Antennal segment VIII is somewhat elongate with the base narrowly fused to segment VII, and the sensorium on segment II is mostly situated between the base and the middle of the segment, but this is somewhat variable. Moreover, the prothoracic episternum is reduced to a very slender plate along the pleural suture. Because of these, we consider that this new genus could be included in the tribe Plectrothripini , despite the prothoracic ferna being largely developed, the mesopresternum absent and mesoeusternum strongly eroded. Abdominal tergite II is not eroded laterally, and this may be plesiomorphic character state and peculiar in the Plectrothripini . Using the key in Mound & Ng (2018), Nazonothrips runs to couplet 12 that separates two genera, Menothrips and Plectrothrips , but it can be distinguished easily from these two genera by having two pairs of prominent setae on the pronotal shield, strongly eroded mesoeusternum, and complete abdominal tergite II which is not eroded laterally. It also seems somewhat similar to the genus Sophiothrips considering the short head with short maxillary stylets and the wide based pelta, especially in the macropterous females, but the antennae are different. Both fore and hind wings are lost leaving basal small parts in all four macropterous females including holotype of Nazonothrips studied below, and only a minute seta remains on the right fore wing of a non-paratypic specimen but the chaetotaxy of subbasal setae is unclear. Nazonothrips wings are often cut off leaving only the basal parts such as in Plicothrips apicalis in the Haplothripini (see Bhatti, 1979).

The generic name is derived from the Japanese ‘ nazono ’ meaning enigmatic.

Figures

FIGURES 2–13. Nazonothrips toshifumii gen. et sp. n., female, 2–3. (2) Macroptera; (3) Aptera. Gynecoid male aptera, 4–5. (4) Large individual; (5) Small individual.Allometric male aptera, 6–7. (6) Large individual; (7) Small individual. Female macroptera, 8–13. (8) Head & pronotum; (9) Antenna; (10) Mesonotum–pelta; (11) Pro-metasterna; (12) Tergite V; (13) Tergite IX & tube.

FIGURES 14–20. Nazonothrips toshifumii gen. et sp. n., head–pelta, 14–16. (14) Female aptera; (15) Gynecoid male aptera, large individual; (16) Gynecoid male aptera, small individual. Pro-metasterna, 17–18. (17) Female aptera; (18) Gynecoid male aptera. Fore leg, 19–20. (19) Female aptera; (20) Gynecoid male aptera.

FIGURES 21–24. Nazonothrips toshifumii gen. et sp. n., allometric male aptera. (21) Head–pelta, small individual; (22) Head– pronotum, large individual; (23) Pro-metasterna; (24) Fore leg.