Thrips wedeliae (Priesner)

Tyagi, Kaomud, Kumar, Vikas & Pal, Shash, 2024, Thrips wedeliae (Priesner) (Thysanoptera: Thripidae) new to India: first description of the male, Zootaxa 5489 (1), pp. 125-128 : 125-128

Thrips wedeliae (Priesner)

( Figs 1–14 )

Male macroptera. Body including legs yellow ( Fig. 2 ). Antennal segments I–III pale, IV–V bicoloured, pale at base, brown shading at apex; VI–VII light brown ( Fig. 4 ). Fore wing pale yellow ( Fig. 14 ). Head longer than broad, cheeks rounded, ocellar setae pair I absent, III much longer than II and arising outside the ocellar triangle; postocular setae I well developed, the longest ( Fig. 9 ). Antenna 7-segmented, III and IV each with forked sense cones. Pronotal surface without sculpture; two pairs of well-developed posteroangular setae; three pairs of posteromarginal setae, median pair much longer than submedian. Mesonotum without lines of sculpture near to anteromedian campaniform sensilla. Metanotum with longitudinally lines in middle, converging towards posterior end; median pair of setae situated on anterior margin; distance between median pair of metanotal setae more than distance between median and submedian; campaniform sensilla present ( Fig. 10 ). Fore wing first vein with complete row of setae, second vein with 12 setae ( Fig. 14 ); clavus with 5+1 setae, apical and subapical setae subequal in length. Abdominal tergites IV to VIII with paired ctenidia, posteromesad of spiracles on VIII; tergite II with 4 lateral marginal setae; posterior margin of abdominal tergite VIII without comb but with weak scallops ( Fig. 11 ); S1 setae on tergite IX longer than S2 and slightly closer to S2. Abdominal sternites II–VII with discal setae; sternites III–VII each with a broad transverse pore plate ( Fig. 12 ).

Measurements (in microns). Distended body length 1212. Head, length 121; width behind eyes 37; width across cheeks 110; compound eye dorsal length 61, width 42. Pronotal median length 125, width 155; posteroangular setae I (inner pair) 64, setae II (outer pair) length 62; posteromarginal setae I length 30. Fore wing length 520, width at middle 41. Abdominal tergite IX S1 setae length 14–16, S2 setae length 10–12. Antennal segments I–VII length (width) as follows: 25(24), 34 (20), 48 (17), 51 (15), 35(12), 48 (15), 17 (9). L(W) of pore plates on abdominal sternites III–VII: 99(14), 99(16), 94(12), 90(16), 81(16).

Female macroptera. Body uniformly dark brown including femora, fore wing dark with base slightly paler, all tibiae and tarsi pale ( Fig. 1 ). Antennal segments I brown, II with light brown shade in basal half, III pale, IV–VI bicoloured, VI– VII brown ( Fig. 3 ). Antennae 7- or 8-segmented; ocellar setae III well developed and situated outside the ocellar triangle ( Fig. 5 ). Metanotum with striate sculpture; median setae situated at anterior margin; campaniform sensilla present ( Fig. 6 ). Fore wing first vein with an almost complete row of setae, 5 basal, 6 median and 4 distal setae ( Fig. 13 ); clavus with 5 setae more or less equal to subapical or slightly longer. Tergite II with 4 lateral marginal setae [ Palmer (1992) mentioned 3 lateral setae on tergite II in the specimens from Guam, Taiwan, and Tahiti, whereas 4 setae were in the specimens from the Solomon Islands, which were deposited in BMNH, London]; tergite VIII posteromarginal comb complete but irregular ( Fig. 8 ). Abdominal sternites III–VII with 5–16 discal setae, 1–2 on sternite II ( Fig. 7 ). Pleurotergites without discal setae.

Material studied. INDIA: Uttarakhand: Dehradun , 9 females, 6 males, 24.iv.2023, collected on Solanum mauritianum , leg. Vipin (Reg. No. 27210/H17–27224/H17) .

Remarks. Palmer (1992) proposed five groups (I–V) to distinguish species of the genus Thrips based on a few morphological characteristics. Thrips wedeliae (Priesner) is a member of group V and can be distinguished from other groups by the presence of discal setae on abdominal sternites III–VII, the absence of discal setae on pleurotergites, and the presence of an irregular comb of microtrichia on the posterior margin of abdominal tergite VIII. Thrips wedeliae belongs to the sumatrensis group, which includes T. sumatrensis Priesner , T. samoaensis (Moulton) , T. vitticornis (Karny) , T. cinchonae Priesner , and T. fulmeki (Priesner) , and shares a complete row of setae on the first vein of forewing; striate metanotal sculpture; pleurotergites without discal setae; and sternites III–VII with discal setae ( Palmer 1992), and differing in small variations in structure and colour.

Further, T. wedeliae can be distinguished from T. cinchonae by the colour of antennal segments III and IV, which are bicoloured in T. wedeliae and brown in T. cinchonae ; tergite VIII with short and irregular microtrichia in T. wedeliae but long, fine and regular in T. cinchonae . Moreover, T. wedeliae can be distinguished from T. samoaensis , and T. vitticornis by the posteromarginal comb of microtrichia on tergite VIII, which is short and irregular in T. wedeliae and restricted to lateral sides in T. vitticornis . Moreover, T. wedeliae can be differentiated from T. samoaensis by the colour of the antennal segments IV and V which are brown in T. samoaensis and bicoloured in T. wedeliae .

The female of T. wedeliae is very difficult to identify, as it will easily be confused with T. sumatrensis . In this study, two females and one male of T. sumatrensis were studied to compare the Indian specimens [one female and one male of T. sumatrensis from Solomon Island (Melanesien), 3-xii-1975, N.L.H. Krauss leg., identified by R. zur Strassen on viii-1976 (SMF T 7013) (NZC Registration No. 22620/H17 to 22621/H17), and one female from Java (NZC Registration No. 22577/H17), donated by Dr. J.S. Bhatti to Zoological Survey of India] ( Fig. 16 ). Females of T. sumatrensis and T. wedeliae are very difficult to separate; however, male specimens can be differentiated from each other by the shape of the transverse pore plates, which are broader in T. wedeliae [III–VII: 99(14), 99(16), 94(12), 90(16), 81(16)] as compared to T. sumatrensis [III–VII: 78(11), 79(10), 76(7), 73(8), 64(8)] ( Fig. 15 ). Moreover, tergite VIII without comb of microtrichia but with scallopes at their posterior margin in T. wedeliae , whereas T. sumatrensis possesses very short, sparse and indistinct microtrichia at their posterior margin.

Figures

FIGURES 1–14. Thrips wedeliae (1) Female; (2) Male; (3) Antenna, female; (4) Antenna, male; (5) Head and pronotum, female; (6) Meso-and metanotum, female; (7) Sternites IV–VII, female; (8) Tergite VIII, female; (9) Head and pronotum, male; (10) Meso- and metanotum, male; (11) Tergite VII–X, male; (12) Sternites III–VII, male; (13) Fore wing, female; (14) Fore wing, male.

FIGURES 15–16. Thrips sumatrensis (15) Sternites III–VII, male; (16) Slide mounted specimens examined in this study.