Stephanothrips austrinus, Tong, Xiaoli & Zhao, Chao, 2017

Tong, Xiaoli & Zhao, Chao, 2017, Review of fungus-feeding urothripine species from China, with descriptions of two new species (Thysanoptera: Phlaeothripidae), Zootaxa 4237 (2), pp. 307-320 : 311-314

Stephanothrips austrinus sp. n.

( Figs 1 , 13–19 , 30 )

Female. Apterous ( Fig. 1 ). Head and prothorax brown; pterothorax yellow, but mesothorax with brown areas anterolaterally and metathorax brown laterally. Abdominal tergite I brown, tergites II–VIII yellow with brown markings laterally, tergite IX yellow with lateral margin brown, tube yellow with extreme apex brown. Antennae yellow except segments IV–V brown. Fore coxae brown, fore femora brown with yellow apically and basally, fore tibiae yellow; mid legs yellowish white; hind legs largely brown, but bases and apices of femora and tibiae yellow; all tarsi pale yellow with a brown marking apically.

Head ( Fig. 13 ) slightly longer than wide, dorsal surface and cheeks strongly tuberculate; cheeks gradually widened towards base, but constricted at base; anterior margin of head slightly produced and arched in front of eyes, with 2 pairs of anterior cephalic setae, inner pair long and knobbed at apices, outer pair short and slightly dilated at apices, about 1/4–1/3 length of inner pair ( Fig. 13 ). Eyes each with only 3 ommatidia dorsally; ocelli absent. Antennae 5-segmented ( Fig 17 ), segment III (morphological segments III–V) longer than other segments and with indistinct sutures between the morphological segments, the fifth visible segment with an incomplete suture between morphological segments VII and VIII; antennal segment III with 3 sense cones (morphological segment IV with 2 sense cones and V with 1). Maxillary stylets retracted as far as eyes, subparallel and about onesixth head width apart medially.

Pronotum ( Fig. 14 ) transverse approximately 1.8 times as wide as long, dorsal surface sculptured with irregular wrinkles medially and being surrounded by small tubercles; pronotum with a pair of prominent epimeral setae, slightly dilated at apices; epimeral suture incomplete. Basantra present laterally but weak and membranous submedially; ferna well-developed and separated ( Fig. 19 ). Meso- and metanotum weakly sculptured medially ( Fig. 15 ), metaepimera slightly bulged, with small tubercles but lacking major setae; mesopresternum weak and membranous; anterior margin of mesoeusternum with a longitudinal median split ( Fig. 19 ); meso- and metafurcae situated laterally and widely separated ( Fig. 19 ). Legs short and tuberculate; fore tarsus without hamus ( Fig. 18 ), hind tarsi each with a dorsal claw.

Abdomen broadest at segment II and tapering evenly to the tube. Abdominal tergite I transverse and distinctly sculptured, closely fused to tergite II ( Fig. 15 ), and clearly separated with metanotum; tergite II with two pairs of minute posteromarginal setae and a transverse row of 18–20 minute setae ( Fig. 16 ), posterolateral setae minute with similar size as postermarginal setae; tergites III–VIII each with a pair of well-developed spatulate posterolateral setae, and intermediate tergites each with three pairs of short posteromarginal setae and a transverse row of 14–20 minute setae; tergite IX near 1.9 times as long as maximum wide, slightly shorter than head. Tube about 9 times as long as apical width, about 1.3 times as long as head; tube with 6 terminal setae apparently equal in length, anal setae 2.8 times as long as tube.

Measurements (holotype female in microns). Total distended body length 1430. Head length 180, maximum width 173. Pronotum length 105, median width 195. Abdominal tergite IX length 170, maximum width near base 100 and distal width 40. Tube length 230, basal width 20 and apical width 28. Antennae segments I to V length (width) as follows: 20 (25), 28 (30), 93 (25), 24 (16), 38 (14). Length of setae: inner pair of cephalic setae 40, outer pair 10; pronotal epimeral setae 15; anal terminal setae about 580.

Male. Unknown.

Specimens examined (all specimens were collected from leaf-litter unless otherwise noted). Holotype female (in SCAU): CHINA, Guangdong, Guangzhou City, Conghua, Liangkou Town , Niulu (24°74'N, 113°73'E), collected from leaf litter, 29.xi.2011 (Shulan Yang).

Paratypes (in SCAU, all specimens were collected from leaf litter unless otherwise noted): 9 females, collected with holotype. Guangdong, Zhaoqing City, Dinghushan National Nature Reserve (23°10'N, 112°32'E), 6 females, 4.vi.1985 (Xiaoli Tong). Huizhou City, Mt. Nankunshan (23°38'38"N, 113°50'49"E), 1 female, 14.xi.2001 (Zhiwei Li). Shixing County, The Chebaling National Nature Reserve (24°42′N, 114°11′E), 5 females, 10.x.2002 (Zhiwei Li). Yingde City , Shimentai Nature Reserve (24°24'30"N, 113°18'18"E), 3 female, 12.iv.2002 (Zhiwei Li), 2 females, 7.iv.2011 (Tao Song). Guangzhou City , Conghua , Sanyatang (23°44′N, 113°48′E), 12 females, 28.x.2004 (Jun Wang). Haifeng County , Mt. Lianhuashan (23°03'N, 115°15'E), 1 female, 13.iii.2005, 2 females, 4.v.2005 (Jun Wang). Guangzhou City , Longdong Forest Park (23°14'N, 113°24'E), 2 females, 4.v.2005 (Jun Wang). Xinyi City , Mt. Tianmashan (22°27'N, 110°41'E), 3 females, 2.iv.2011 (Tao Song), 6 females, 21.viii.2011 (Tao Song), 1 female, 18.ix.2011 (Tao Song). Dongguan City , Mt. Yinpingshan (22°54'09"N, 114°09'42"E), 1 female, 10.ix.2014 (Chao Zhao). Guangzhou City , Conghua , Liangkou Town , Xitou (23°43′N, 113°51′E), 1 female, 28.viii.2015 (Chao Zhao) . Jiangxi, Jinggangshan City, Mt. Jinggangshan National Nature Reserve (114°7′E, 26°37′N, alt. 1200m), 1 female from dead leaves of Cryptomeria fortune (Taxodiaceae) , 26.viii.2015 (Chao Zhao).

Distribution. China (Guangdong, Jiangxi).

Etymology. The specific epithet, austrinus , is from the Latin adjective, meaning “southern”, in reference to this new species is so far mainly distributed in the southern China.

Comments. This new species appears to be closely related to S. kentingensis and S. zonatus ; all three have two pairs of anterior cephalic setae—inner pair elongate, outer pair short. However, kentingensis differs from this new species as follows: antennal segment IV, hind femora (including coxae) and abdominal tergite I largely yellow (brown in austrinus ); pronotal epimeral setae apparently tiny or absent (well-developed in austrinus ). The new species can also be distinguished from zonatus by the fore tarsus lacking an external hook-like hamus (present in zonatus ).

The genus Stephanothrips differs from Baenothrips , Bradythrips and Urothrips on very minor characteristics ( Mound 1972; Okajima 2006; Ulitzka & Mound 2014). Recently, Ulitzka and Mound (2014) produced a new diagnosis of the genus Urothrips . Although they mentioned “basantra absent” in Urothrips , it actually could be interpreted as “basantra present but reduced to small lateral plates” (personal communication with Laurence Mound). These lateral plates are the same as those found in the above four genera. During the examination of a series of Chinese urothripine specimens, we found one of thoracic structural characters, the meso- and metafurcae placed laterally and widely separated, could be used to separate Stephanothrips from other members in the key to genera of urothripine. This character was previously mentioned by Stannard (1970) and Mound (1972), but most published figures of Stephanothrips do not show detail of this character, or it is usually neglected or understated in descriptions. This thoracic structural character is probably associated with the extreme apterous condition in this lineage.

There are two distribution patterns of the genus Stephanothrips in China ( Fig. 30 ). Two species seem to have a more restricted distribution, but the other three species, S. japonicus , S. occidentalis and S. austrinus sp. n., are widely distributed in China. S. occidentalis is widespread in the tropics and subtropics of world ( Mound 1972; Okajima 1994; Diffie et al. 2008). Unlike the other Stephanothrips species that are found mainly in leaf litter, dead twigs or top soil layers, S. occidentalis is found not only in leaf litter, but also on fresh leaf or stem of various living plants, and is likely to be dispersed by wind ( Mound 1972). S. japonicus ( Fig 30 ) also has a wide geographical range, from Japan, Taiwan and mainland China ( Okajima 1994, 2006; Wang & Tong 2007), and is also known from southeastern U.S.A. ( Diffie et al. 2008). Despite this, no males have ever been found in China. S. austrinus is widely distributed in Guangdong province, southern China, and often co-occurs with S. japonicus .

Figures

FIGURE 30. Distribution map of Stephanothrips species in China.

FIGURES 1 – 6. Habitus of female: (1) Stephanothrips austrinus sp. n.; (2) S. japonicus Saikawa; (3) S. kentingensis Okajima; (4) S. occidentalis Hood & Williams; (5) Bradythrips zhangi Wang & Tong; (6) Habrothrips curiosus Ananthakrishnan

FIGURES 13 – 18. Stephanothrips austrinus sp. n.: (13) head; (14) head and thorax; (15) meso- and metanotum, abdominal tergites I – II; (16) abdominal tergites I – III; (17) antenna; (18) fore leg.

FIGURES 19 – 22. Mesoeusternum, meso- and metafurcae of Stephanothrips spp.: (19) S. austrinus sp. n.; (20) S. japonicus; (21) S. kentingensis; (22) S. occidentalis