Karnyothrips acutus, Okajima & Masumoto, 2025

Karnyothrips acutus sp. n.

( Figs 11 View FIGURES 6–20 , 41–47 View FIGURES 41–47 )

Female (macroptera). Distended body length: 1.5–2.0mm. Brown species ( Fig. 11 View FIGURES 6–20 ). Abdomen often somewhat paler than head and thorax, but gradually darkened posteriorly. Femora brown with apices yellowish; tibiae yellowish, very weakly shaded with pale brown; tarsi yellow. Antennal segments I and VII – VIII brown, almost concolorous with head or a little paler, segment II pale brown, yellowish externally, segment III yellow, segments IV – VI pale grayish brown, gradually darkened distally, each segment with base yellowish, segment VI a little paler than segment VII. Wings and major body setae pale. Head about 1.4 times as long as wide ( Fig. 41 View FIGURES 41–47 ), 1.41 times in holotype, widest across cheeks at the level of postocular setae, dorsal surface almost smooth, often very weakly sculptured with transverse striae or wrinkles at middle between postocular setae. Cheeks rounded, weakly serrate. Postocular setae shorter than eyes, expanded at apex, 120µm apart from each other, 13–14µm apart from eyes in holotype. Eyes about one-third as long as head, 0.32–0.33 times in holotype. Ocelli relatively small; posterior pair 34µm apart from each other in holotype. Antennae about 1.6 times as long as head, 1.56 times in holotype; segment VIII not constricted basally ( Fig. 45 View FIGURES 41–47 ), widely fused to segment VII, about two-thirds as long as VII; segment III with sub-basal swelling ( Fig. 46 View FIGURES 41–47 ), almost as long as segment IV or a little shorter; segments III and VII subequal in length; segments III and IV each with two sense cones, (1+1) and (1+1 +1) respectively. Maxillary stylets reaching postocular setae, relatively wider apart, 0.2–0.3 times as wide as head, 34µm apart from each other in holotype; maxillary bridge wide and rather distinct. Pronotum 0.6–0.7 times as long as head, 1.48 times as wide as long in holotype, almost smooth; four pairs of prominent setae expanded; aa and ml subequal in length, shorter than pa, epim the longest. Notopleural sutures usually complete, often incomplete, right one incomplete in holotype. Prospinasternum moderately large, fan-shaped, 35µm wide in holotype; mesopresternum narrowly boat-shaped, not divided ( Fig. 43 View FIGURES 41–47 ). Metanotum almost smooth medially; median pair of setae weak, short and acute, about 20µm in length, 41µm apart from each other, 47–48µm apart from anterior margin. Fore wing with 4–5 duplicated cilia; three sub-basal setae expanded, S2 a little shorter than S1, S3 the longest. Pelta trapezoid ( Fig. 44 View FIGURES 41–47 ), sculptured weakly, 1.16 times as wide as long in holotype. Tergite IX S1 and S2 setae sharply pointed, S1 longer than tube, 1.1–1.2 times as long as tube, S2 much longer than S1. Tube about 0.45–0.51 times as long as head, 1.7–1.9 times as long as wide. Terminal setae about 2.0 times as long as tube .

Measurements (holotype female in µm). Body length about 1870 (distended). Head length 205, from anterior margin of eyes 187, width across eyes 142, maximum width across cheeks 145; eyes length 66–67; diameter of posterior ocelli 11–12; postocular setae 40–42. Maxillary bridge width 38. Antenna total length 320, segments III–VIII length (width) as follows: 43 (26), 43 (27), 40 (25), 37 (22), 42 (19), 28 (15). Pronotum length 125, width 185. Setae on prothorax: aa 23–27, ml?25, pa 35, epim 40–41. Fore wing length 660. Sub-basal wing setae: S1 26, S2 24, S3 32 –34. Pelta length 69, width 80. Tergite IX setae: S1 100–105, S2 140–148. Tube length 92, maximum width 53; terminal setae?.

Male (macroptera). Distended body length: 1.3-1.6mm. Very similar in color and structure to macropterous female. Head 1.35–1.40 times as long as wide ( Fig. 42 View FIGURES 41–47 ); maxillary stylets wider apart, usually more than 0.33 times as wide as head. Tergite IX S1 setae variable in shape and length, expanded, blunt or pointed.

Measurements (paratype male in µm). Body length about 1500 (distended). Head length 184, from anterior margin of eyes 169, width across eyes 128, maximum width across cheeks 134; eyes length 66–67; diameter of posterior ocelli 11–14; postocular setae 30–33. Maxillary bridge width 53. Antenna total length 310, segments III–VIII length as follows: 40, 42, 38, 37, 40, 24. Pronotum length 118, width 185. Setae on prothorax: aa about 20, ml 30, pa 25, epim 37–38. Fore wing length 590. Sub-basal wing setae: S1 24 –26, S2 22, S3 27 –28. Pelta length 58, width 70. Tergite IX setae: S1 57 –60, S2 34 –39. Tube length 85, maximum width 45; terminal setae 180.

Type material. Holotype: macropterous female, Thailand, nr. Chiang Mai, Doi Suthep , on bamboo, 24.viii.1992, TN & SO . Paratypes: Thailand, 6 females (mac.) and 4 males (mac.), collected together with holotype ; 2 females (mac.) and 1 male (mac.), same locality and habitat as holotype, 1.ix.1991, TN & SO; 1 female (mac.) and 1 male (mac.), nr. Chiang Mai, Phrow , on bamboo, 22.viii.1992, TN & SO ; 1 female (mac.), nr. Chiang Mai, Ka Jan , on bamboo, 3.ix.1992, SO ; 1 female (mac.), nr. Kanchanaburi, on bamboo, 30.viii.1991, TN & SO .

Non-paratypic specimens. Taiwan, 3 females (mac.), Chiai Hsien, Kuantzulin, on grass, 1.iv.1993, TN & SO ; 2 females (mac.), same data as above, on bamboo, 2.iv.1993, SO ; 5 females (mac.), Taitung Hsien, Chihpen, on bamboo, 10.ix.1993, TN & SO . Japan, 1 female (mac.), Okinawa-ken, Okinawa-hontou Is., Nago-shi, Nago-jyoshi, on dead branches, 26.viii.1988, SO .

Comments. This species is easily distinguished by a combination of the following features: antennal segment III with sub-basal swelling, segment IV with two (1+1 +1) major sense cones; maxillary stylets relatively wider apart, about 0.3 times as wide as head; S1 setae on tergite IX sharply pointed. The form of antennal segment III is similar to that of antennalis and inflavus from Japan, but they have tergite IX S1 setae expanded in female. Interestingly, however, the male has the S1 setae on tergite IX variable in length and shape, expanded, blunt or pointed. It is somewhat intermediate between Karnyothrips and Xylaplothrips (in part) in having the prosternal basantra and ferna closer together. Ten females from Taiwan and one female from Japan listed in the non-paratypic specimens could not be distinguished from the type series, but antennal segment III has the sub-basal swelling more distinct ( Fig. 47 View FIGURES 41–47 ). Most of the specimens of this species have been collected from bamboo.