Chirothrips hemingi, Nakahara, Sueo & Foottit, Robert G., 2012

Nakahara, Sueo & Foottit, Robert G., 2012, Review of Chirothrips and related genera (Thysanoptera: Thripidae) of the Americas, with descriptions of one new genus and four new species, Zootaxa 3251, pp. 1-29 : 12-15

Chirothrips hemingi sp.n.

( Figs 18–30 )

Female. Macropterous. Body brown with orange-red internal pigments, or abdomen yellowish brown with posterior three segments darker brown; legs brown except fore tarsi yellow, mid- and hind tarsi yellow or yellowish brown, fore tarsi distally yellow, brown basally; ocellar crescent red; fore wings light yellow, distally light brownish yellow, fore- and hind vein darker yellow; body setae brown, fore wing setae yellow or brownish yellow; antenna brown except segment III light brown or yellowish brown with pedicel pale, II with lateral process yellowish brown.

Antenna ( Fig. 18 ): Segment I about twice as wide as base of segment II; segment II with inner margin convex, lateral margin diverging from base distally to subapical seta or initially diverging and then bulging outward to subapical seta and projecting laterad as a subtruncate, blunt or pointed, sclerotized process; segments IV and V gradually widening distally to position of subapical setae; segment VIII longer than VII; segments III and IV each with simple sense cone; inner sense cone of segment V longer than outer sense cone, inner sense cone on segment VI in distal 1/3 of segment.

Head ( Fig. 19 ): Longer than wide, prolonged anterior of eyes, lateral margin anterior of compound eyes short, extending to rounded angle or margin curved anteromediad, compound eye about twice as long as occiput, occiput with transverse sculpture lines or anastomosing lines, between and anterior of compound eyes without sculpturing; 6–8 short setae on vertex; ocellar setae slightly anterior, laterad or posterior of anterior ocellus; postocular setae minute, 1 posterior of each posterior ocellus, 2 just posterior of eyes; usually 3–4 minute medial pores between first PO setae and posterior ocelli; mouthcone broadly conical, rounded at apex, shorter than head.

Pronotum ( Fig. 21 ): Subtrapezoidal, anterior margin considerably shorter than posterior margin, wider than long, sculptured with transverse lines or anastomosing; 41 (44–49) short, discal setae in 2 submedial rows and submarginally, with medial and 2 submedial setae-less areas; 2 pairs of well developed posteroangular setae; posteromarginal setae 8–9, medial pair usually slightly longer than others. Prosternum ( Fig 22 ) with basantra membranous, finely striate-rugulose, without setae; ferna divided. Mesonotum ( Fig. 23 ): With transverse sculpturing or partially reticulated; anteromedian pair of campaniform sensilla rather far apart; median setae about aligned with lateral setae, posterior setae slightly anterior of margin. Mesosternal spinula absent ( Fig. 22 ). Metanotum ( Fig. 24 ): With transverse sculpture lines or reticulated with recticles transversely oriented medially, arched lines in posteromedial part, lateral sculpture lines longitudinally aligned; median pair of setae in anterior 1/ 4 of notum, about 42 µm long, shorter than lateral pair; 2 campaniform sensilla present. Legs: Fore femora enlarged, with series of ridges on dorsal surface, apical margin reflected; fore tibiae apically truncate.

Fore wings: Straight, gradually narrowed distally to blunt apex; 22 (25–26) costal setae, those at midlength about 3/5 as long as width of wing; 27 anterior fringe cilia, mostly straight, few slightly wavy; fore vein with 6 setae in proximal 1/2 and 2–3 setae in distal 1/2; hindvein with 6–7 setae; clavus with 5 veinal and 1 discal setae.

Abdomen: Tergites ( Fig. 25 ) sculptured with transverse or anastomosing striae, 12–15 lines medially posterior of antecostal ridge, none differentiated from others; median setae on tergite I minute, on tergites II–VII subequal to D2 setae, slightly anterior to median campaniform sensilla on tergite VIII, between or slightly anterior to median campaniform sensilla on tergites II–VII; area between median campaniform sensilla and antecostal ridge with 4–5 striae on tergites IV–VII; posteromarginal flange short, subequal to distance between sculpture lines, margin normally undulating or irregular; tergite IX with 2 pairs of campaniform sensilla; tergite X long, conical, 1.5–1.75 times longer than tergite IX, with 1 pair of campaniform sensilla just anterior of B1 setae. Pleurotergites with posteromarginal teeth. Sternites ( Fig. 26 ) with transverse lines, none differentiated from others except antecostal ridge; sternite I with 2–4 anteromedial setae. Sternite II with 2 or 3 pairs of posteromarginal setae, sternites III–VII with 3 pairs of posteromarginal setae on margin except B1 setae on sternite VII anterior of posterior margin, closer to B2 setae than to each other; small lobes on posterior margins of sternites II–VII; ovipositor 267 (247–272) µm long.

Measurements of holotype (and female paratypes). Body length: 1.74 (2.06–2.17 distended) mm. Other measurements in µm. Antenna: total length 252 (245–250); length, width of antennal segment I 22 (22–24), 35 (37); II 37 (37), 42 (40–42); III 40 (37–40), 24 (24–27); IV 40 (35–40), 24 (24–27); V 37 (32–35), 22 (22–23); VI 49 (48–50), 20 (20); VII 10 (12), 10 (7); VIII 17 (15–17), 6 (5). Head: length from interantennal projection 151 (153–161); produced marginal part anterior of eye 17 (15); eye 74 (74–79) long; occiput 37 (37) long. Pronotum 235 (203–230) long, 274 (247–272) wide. Fore wing 1099 (1025–1062) long, 62 (62) wide at midlength. Abdominal segment IX (72–82), X 133 (124–148). Setae: ocellar setae about 15 long; posteroangular setae outer pair 43 (42–57), inner pair 37 (37–50); median metanotal setae about 17 long; abdominal tergite IX with B1 setae 126 (114–131), B2 setae 138 (114–128); tergite X with B1 setae 131 (128–137), B2 setae 124 (117–124).

Male. Brachypterous. Similar to females in color but smaller. Antenna: Similar to females. Head: Similar to females except without ocellus; vertex with 8 short setae, ocellar setae at midlength or slightly posterior.

Pronotum: Sculptured with transversely oriented lines; about 49 short, discal setae in 2 submedial rows and on submargin; 2 pairs of developed posteroangular setae, and about 10 posteromarginal setae. Metanotum ( Fig. 27 ): Subrectanglar, transversely sculptured; median setae in anterior 1/4 of notum, lateral setae posterior of anterior margin; 2 campaniform sensilla at about midlength of notum.

Abdomen: Tergal posteromarginal flange subequal to length of 2 tergal, interstrial spaces or slightly longer, margin with lobes or teeth. Abdominal tergite IX ( Fig. 29 ) with B1 setae posteromediad of longer Dl setae, B2 setae posterolaterad of B1 setae, posterolateral setae and midlateral setae long, a shorter seta between posterolateral and midlateral setae; a campaniform sensillum between Dl and B1 setae or posterior of Dl setae, another pair near anterior margin of tergite. Sternites with conical or low lobes on posterior margins; sternites III ( Fig. 28 ) and IV each with a small circular or slightly oval glandular area 12–15 µm wide, smaller than distance between B1 setae.

Measurements of male paratype. Body length 1.33 mm distended. Other measurements in µm. Antenna: total length 201; length, width of segment I 20, 32; II 27, 25; III 35, 23; IV 35, 24; V 27, 22; VI 37, 18; VII 8, 7; VIII 12, 5. Head: length from interantennal process 131; eye 62 long; occiput 35 long; width at occiput 117. Pronotum 205 long, 225 wide. Setal lengths: posteroangular setae outer pair 24–30; inner pair 37; tergite IX Dl setae 27– 35 long; B1 setae about 10 long; B2 setae about 10 long; posterolateral setae 84–86 long; midlateral setae 82–91 long.

Type material. Holotype female, Canada, Alberta, Jasper, 24-VI-55, grass, R. M. Bohart ( UCD). Paratypes: 1 female with same data as holotype; 4 females, Cypress Hills Provincial Park, Alberta, sweeping grass and forbs, 30-VI-69, B. S. Heming; 3 females, Mt. Norquay, Banff, Alberta, 60001, 25 -V-60, W. W. Moss; 1 female, Whitemud Hills, Alberta, grass, 5-VII-70, B. S. Heming; 27 females, 7 males, Osoyoos, British Columbia, Canada, grass, 30-VII-80, G.A.P. Gibson. Paratypes deposited in CNC, UASM, UCD and USNM.

Distribution. Canada (Alberta, British Columbia).

Etymology. Named after Dr. Bruce Heming, University of Alberta, Edmonton, for providing thrips material for this project and in recognition of his work on the functional morphology and development of Thysanoptera .

Comments. This species resembles C. molesta Priesner from the Palearctic Region. The apex of the lateral process of antennal segment II of C. molesta has a translucent gland, outer sense cone on segment V is longer than inner sense cone, and abdominal tergites lack complete posteromarginal flange but have separated lobes with acuminate apex or lobes that are low and indistinct. The apex of the lateral process of antennal segment II of C. hemingi is sclerotized, inner sense cone on segment V is longer than outer sense cone, and abdominal tergites have short, complete posteromarginal flange normally with lobed margin. In the Nearctic Region, C. hemingi resembles C. productus but is readily separated by the position of the median tergal setae on the abdomen.

The holotype and paratype from Jasper have only 2 pairs of posteromarginal setae on abdominal sternite II and the apex of lateral process of antennal segment II is subtruncate. The paratypes from Mt. Norquay and Cypress Hills Provincial Park have normally 3 pairs of posteromarginal setae on sternite II and antennal segment II has a bluntly pointed process. Antennal segment II is usually tilted and the lateral process appears to be narrower and more pointed.

The convex lateral margins of antennal segment II of some specimens from Osoyoos, British Columbia are quite different from the gradually diverging forms from Alberta and they appear to be a different species. However, the shapes of the lateral margin are variable in a long series of specimens from Osoyoos and part of the range of variation is similar to those of the Alberta specimens. Except for this difference, the other anatomical characters are similar. Description of the male is based on the Osoyoos material.

Figures

FIGURES 18 – 26. Chirothrips hemingi sp. n., holotype female. (18) right antenna; (19) head, dorsal aspect; (20) right compound eye, ventral aspect; (21) pronotum; (22) pro- and mesosterna; (23) mesonotum; (24) metanotum; (25) abdominal tergite V; (26) abdominal segment IV, sternite and pleurite IV. Scale bar 100 μm.

FIGURES 27 – 30. Chirothrips hemingi sp. n., paratype male. (27) metanotum; (28) abdominal sternite IV; (29) abdominal tergite IX; (30) abdominal tergite X. Scale bar 100 μm.