Mystrothrips levis, Zhao, Chao & Tong, Xiaoli, 2017

Zhao, Chao & Tong, Xiaoli, 2017, Two new species and two new records of fungus-feeding Phlaeothripinae from China (Thysanoptera, Phlaeothripidae), ZooKeys 694, pp. 1-10 : 2-3

Mystrothrips levis sp. n. Figs 1-8

Material examined

(females and males all apterous). Holotype. Female aptera: CHINA, Guangdong: Guangzhou City, South China Botanical Garden (23Guangdong: Guan), in leaf litter of bamboo, 9.viii.2014 (Chao Zhao).

Paratypes. 8 females 2 males, collected with holotype; 5 females 1 male, the same locality but collected on 20.xi.2015 (Chao Zhao).

Description.

Female aptera (Fig. 1). Body and antennae uniformly brown. All legs yellowish brown except for tarsi yellow.

Head (Fig. 3) almost as long as broad; dorsal surface smooth medially but with polygonal reticulation between eyes and faint reticulation laterally and posteriorly; cheeks slightly convex and weakly constricted just behind eyes; eyes small and bulging, slightly less than 1/4 of head length; postocular setae long and expanded at apex, approximately half of head length; ocelli absent; postocellar setae and mid-dorsal setae as long as eyes, pointed at apex. Antennae 8-segmented (Fig. 8), approximately 2.5 times as long as head; segments III and IV with two and three sense cones, respectively; segments II–V sculptured; segment VIII strongly constricted at base. Maxillary stylets nearly retracted to postocular setae, approximately one-third of head width apart medially.

Pronotum dorsal surface almost smooth but with faint transverse lines anteriorly; notopleural sutures complete; five pairs of major setae long and expanded (Fig. 4). Basantra present but small; ferna and prospinasternum well-developed. Mesonotum sculptured with distinctly transverse reticulation, and a pair of well-developed long lateral setae expanded at apex; mesopresternum eroded medially, divided into two small irregular lateral plates. Metanotum weakly sculptured with polygonal reticulation, a pair of long and acute setae situated medially (Fig. 5); meso- and metasternum smooth; metathoracic sternopleural sutures absent (Fig. 6); mesoeusternum anterior margin entire, mesothoracic furcae united together medially, but metathoracic furcae separated. Fore tarsal tooth absent.

Pelta nearly semicircular in shape with short lateral lobes, distinctly reticulate, a pair of campaniform sensilla present (Fig. 7); abdominal tergites weakly sculptured with reticulation, without developed sigmoid wing retaining setae; S1 and S2 setae on tergites II–VIII well-developed, long and expanded at apex; S1 setae on tergite II much longer than S2, approximately 3.0 times as long as S2; tergites III–VII with S1 and S2 setae subequal in length; S1 on tergite VIII approximately 0.7 times as long as S2; tergite IX with S1 and S2 setae subequal in length, longer than tube, weakly pointed or blunt at apex; abdominal sternites II–VIII with a transverse row of 8-16 discal setae medially, each sternite bearing two pairs of long and pointed setae arising in front of posterior margin. Tube approximately 4/5 of head length; anal setae shorter than tube.

Measurements (holotype female in microns). Distended body length 2030. Head length 190, width 185; eyes length 50; postocular setae length 75. Antennae length 470, segments I–VIII length (width) as follows: 49(43); 53(41); 68(32); 67(34); 65(34); 61(30); 54(24); 52(12). Pronotum median length 140, width across median part 310; length of major setae: pronotum anteromarginal setae 48, anteroangular setae 68, midlateral setae 90, posteroangular setae 85, epimeral setae 80. Metanotum median setae 40. Pelta length 100, width at base 170. Abdominal tergite IX S1 setae length 190, intermediate setae length 85, S2 length 190. Tube length 155, width at base 93, at apex 42; anal setae length 135.

Male aptera (Fig. 2): Similar to apterous female in color and structure but smaller. Fore tarsal tooth present; tergite IX with S1 setae approximately 3.0 times as long as S2; sternites without pore plate.

Measurements (paratype male in microns). Distended body length 1620. Head length 160, width 155; eyes length 35; postocular setae length 70. Antennae length 375, segments I–VIII length (width) as follows: 34(36); 44(29); 50(32); 50(31); 55(28); 50(25); 45(20); 45(13). Pronotum median length 125, width across median part 260; length of major setae: pronotum anteromarginal setae 60, anteroangular setae 45, midlateral setae 73, posteroangular setae 66, epimeral setae 63. Metanotum median setae 30. Pelta length 65, width at base 110. Abdominal tergite IX setae S1 length 145, intermediate setae length 60, S2 length 45. Tube length 130, width at base 80, at apex 32; anal setae length 110.

Distribution.

China (Guangdong).

Etymology.

The specific epithet, levis , is from the Latin adjective, meaning “smooth”, and refers to the dorsal surface of head and pronotum which are largely smooth. In contrast, most species of this genus are sculptured with distinct polygonal reticulation on head and pronotum.

Remarks.

Of the seven species worldwide listed in the genus Mystrothrips ( ThripsWiki 2017), two are recorded from China. M. longantennus Wang, Tong & Zhang is from southern China, and M. flavidus Okajima is widespread from China (Guangxi, Guangdong and Taiwan) to Japan ( Okajima 2006, Wang et al. 2008, Dang and Qiao 2014). The new species is most similar to M. flavidus in color and structure, but it can be distinguished from the latter by (1) head and pronotum largely smooth (vs sculptured with polygonal reticulation entirely in M. flavidus ); (2) antennae uniformly brown (versus antennae segments I and II distinctly lighter than remaining segments in M. flavidus ); (3) pelta semicircular with short lateral lobes (vs broadly trapezoidal in M. flavidus ); (4) S1 and S2 setae on abdominal tergite IX much longer than tube (vs shorter than tube in M. flavidus ).