Scirtothrips hitam, Ng & Mound & Azidah, 2014

Ng, Y. F., Mound, L. A. & Azidah, A. A., 2014, The genus Scirtothrips (Thysanoptera: Thripidae) in Malaysia, with four new species and comments on Biltothrips, a related genus, Zootaxa 3856 (2), pp. 253-266 : 258-259

Scirtothrips hitam sp.n.

( Figs 9–14 )

Female macroptera. Body pale with brown markings to more uniformly brown, frons dark between antennal sockets; head posterior margin darker; femora, tibiae and tarsi weakly shaded; all antennal segments shaded, segment I scarcely paler than II; fore wings and clavus uniformly shaded, wing sometimes with extreme apex paler; abdominal tergites IV–VII with brown area medially, lateral thirds of tergites varying from uniformly brown to yellow with posterolateral margins brown; antecostal ridge of tergites III–VII dark but interrupted medially; sternites extensively shaded, IV–VII with antecostal ridge dark across segment.

Antennae 8-segmented, forked sensoria on III–IV short, not reaching more than one-third the length of succeeding segment; ocellar triangle with closely spaced transverse striae, ocellar setae III arising between hind ocelli, 2 pairs of po as long as ocellar setae III. Pronotum closely striate, with about 10 discal setae; 4 pairs of posteromarginal setae, pair pm2 not elongate, usually less than 30 microns long and about twice as long as pm1. Metanotum anterior third with arcuate transverse striae, irregular longitudinal reticulations posteriorly; median setae arise behind anterior margin. Fore wing second vein with 2 setae; clavus with 4 marginal setae, usually without discal seta. Abdominal tergites II–VI with S1 small, closer together than their length; VIII with microtrichia extending across anterior median area; IX with microtrichia present posteromedially, X without microtrichia; sternites almost fully covered with rows of microtrichia across segment, microtrichia absent from only small and variable anterior area.

Measurements (female in microns). Distended body length 880. Head width across eyes 148. Pronotum, length 86, width 180; posteromarginal pm1setae 9, pm2 20. Metanotum median setae 19, submedian setae 22. Fore wing, length 484; distal setae on second vein length 16–18. Antennae length 227; segments III–VI length 39, 32, 41, 40. Tergites III–VI S1 length 10–26, distance between bases 8–24.

Male macroptera. Similar in colour and sculpture to female, but smaller and darker; S1 on tergites widely separated, distance between bases almost as long or longer than the length of these setae. Abdominal tergite IX without drepanae.

Material studied. Holotype female: MALAYSIA, Penang, MARDI Seberang Perai, from Artocarpus champeden (Moraceae) , 7.vii.2009 (Ng, Y.F. & Eow, L.X.) (in CISUKM ). Paratypes: 4 females, all collected with holotype, 3 females from Kota Damansara, Community Forest, Selangor (All DNA extracted) 17–19.iv.2011 (Ng, Y.F. & Eow, L.X.); Pahang, Sg Bebar, 1 male from flowering tree, 20–28.ix.2009; Negari Sembilan, Kg. Bertam, 1 female from Averrhoa carambola , 5.v.2010; Selangor, MARDI, 4 females, 2 males from Garcinia mangostana , 25.vi.2008; Universiti Malaya, 8 females from Saraca indica , 24.vii.2011, 1 female from Euodia redlevi , 16.v.2011. INDONESIA, JAVA, Bogor, from Mango, 3 females, 4.vii.2008, 1 female, 25.iv.2008, (in CISUKM, MZUM and ANIC).

Etymology. The species name refers to the dark colour of the body in Malay languages.

Comments. This species shares most structural details with S. dorsalis . It appears to be both polyphagous and widespread in tropical Asia, and is widely distributed in western Malaysia and present in Indonesia. In contrast to the common pest species, dorsalis , the sternites are more extensively covered with microtrichia ( Fig. 14 ), the tergal antecostal ridge is discontinuous medially ( Fig. 12 ), and there are colour differences indicated in the key above. Most specimens are considerably darker than the typical form of S. dorsalis , but the lateral thirds of the tergites are almost yellow in a few, possibly teneral, females.

The NJ, MP and ML trees generated from the COI sequences in the phylogenetic analyses had similar topology. Only the NJ tree is shown here ( Fig. 1 ). All the S. hitam and S. dorsalis samples formed two well supported clusters in the NJ tree indicating these taxa are well separated. The genetic distance between S. hitam and S. dorsalis was sufficiently high ( S. dorsalis (NYF1) vs. S. hitam (NYF 5,6,7) = 0.141) to recognize these as distinct species. However, this recognition might be improved if more extensive sampling could be carried out.

Figures

FIGURE 1. Neighbour-Joining (NJ) tree generated from the analysis of COI sequences. Number above branch indicates bootstrap value (500 replicates).

FIGURES 9–14. Scirtothrips hitam sp.n. (9) Head and pronotum; (10) Metascutum; (11) Antenna; (12) Abdominal tergites IV–VIII; (13) Abdominal tergites VIII–XI; (14) Abdominal sternites IV–VII.