台灣農業研究 (J. Taiwan Agric. Res.) 67(4):323–336 (2018) Research Article DOI:10.6156/JTAR.201812_67(4).0001 Taxonomic Description of Idolothripinae (Thysanoptera: Tubulifera: Phlaeothripidae) of Taiwan. I. Tribe Idolothripini Chin-Ling Wang1, Yi-Ju Chen2, and Feng-Chyi Lin3,* Abstract Wang, C. L., Y. J. Chen, and F. C. Lin. 2018. Taxonomic description of Idolothripinae (Thysanoptera: Tubulifera: Phlaeothripidae) of Taiwan. I. Tribe Idolothripini. J. Taiwan Agric. Res. 67(4):323–336. Five genera and 11 species of Tribe Idolothripini of subfamily Idolothripinae in Taiwan are re- viewed. Identification keys are provided, and diagnostic characteristics are described and illustrated. Dinothrips spinosus (Schmutz) is the first species and genus recorded in Taiwan. Key words: Taxonomy, Thysanoptera, Phlaeothripidae, Idolothripinae, Taiwan. INTRODUCTION to 62 species and 19 genera by Dang & Qiao (2013) who provided illustrated keys to these The thrips, insects belonging to order taxa. Thysanoptera, are divided into two suborders, For Taiwanese Idolothripini, Karny (1913b) Terebrantia and Tubulifera. The suborder Tu- first described 2 new genera and species: bulifera contains a single family Phlaeothripi- Phoxothrips pugilator (= Mecynothrips pugila- dae which is divided into two subfamilies, Ido- tor) and Idolothrips formosanus (= Ophthalmo- lothripinae and Phlaeothripinae. In this study, thrips formosanus). Priesner (1935a) published the members of Idolothripini of subfamily three new species, Elaphrothrips mucronatus, E. Idolothripinae in Taiwan are reviewed. sumbanus, and E. productus, though all species More than 80 genera and 700 species of are synonyms of E. denticollis Bagnall (Mound Idolothripinae have been described worldwide & Palmer 1983). Priesner (1935a) also listed E. (ThripsWiki 2018). The world genera of Ido- formosanus (Karny) [= Ophthalmothrips for- lothripinae was reviewed by Mound & Palmer mosanus (Karny)]. Priesner (1935b) described (1983). Eow et al. (2011) provided a key to two new species, Elaphrothrips clarispinis (= E. 31 genera and 34 species of Idolothripinae in spiniceps Bagnall) and E. takahashii [= Mecy- Peninsular Malaysia and Singapore. Majid et nothrips pugilator (Karny)]. Forty years later, al. (2011) listed 59 species and 18 genera of Haga (1975) recorded Pyrgothrips formosa- this subfamily in China; the number increased nus (Karny) [= Ophthalmothrips formosanus Received: March 4, 2018; Accepted: May 13, 2018. * Corresponding author, e-mail: [email protected] 1 Former Research Fellow, Applied Zoology Division, Taiwan Agricultural Research Institute, Council of Agriculture, Taichung, Tai- wan, ROC. 2 Assistant Research Fellow, Applied Zoology Division, Taiwan Agricultural Research Institute, Council of Agriculture, Taichung, Tai- wan, ROC. 3 Associate Research Fellow, Applied Zoology Division, Taiwan Agricultural Research Institute, Council of Agriculture, Taichung, Tai- wan, ROC. 324 台灣農業研究 第 67 卷 第 4 期 (Karny)] and P. longiceps Haga [= Ophthal- duplicated cilia; pelta broad, usually with lat- mothrips longiceps (Haga)] in Taiwan. Chen eral lobes, rarely without lateral lobes, surface (1982) recognized 10 genera and 15 species with sculptured reticles; tergites II–VII with of Idolothripinae, including 6 species belong- 1–3 pairs of wing retaining setae; male with ing to Idolothripini, of which Megathrips (= S2 setae on tergite IX well developed, equal to Bactrothrips) honoris Bagnall was a new re- or longer than S1 setae. cord. Okajima (1979) described Mecynothrips taiwanus in Taiwan. Recently, he published 3 MATERIALS AND METHODS Bactrothrips species from Japan and Taiwan (Okajima 2006). Specimens studied were mainly from 4 dif- Species of Idolothripinae feed on fungal ferent sources: thrips collected by the authors spores under rotten leaves on ground and on in Taiwan from year 1993 to 2006, permanent dried woody stems and branches. Their feeding slides were preserved and deposited at Taiwan Agricultural Research Institute (TARI); slides behavior does not harm plants. Unlike some deposited at TARI by R. Takashashi; slides Terebrantian thrips, they are never agricultur- deposited at TARI by L. S. Chen; and slides al pests. As with many other tiny organisms, loaned from Tokyo University of Agriculture, though small in size, they play essential roles Japan. in biodiversity and contribute to environmental Identification keys and character descrip- balance. tions were made by microscope examination Diagnostic characters between two and comparison of these slides. subfamilies of Phlaeothripidae (modified from Okajima, 2006) RESULTS AND DISCUSSION Maxillary stylets broader, width in distal half Key to tribes of subfamily Idolothripinae 5–10 microns in diameter, without max- 1 Metasternum without sternopleural su- illary guides; pelta usually with 2 lateral tures, pelta without campaniform sensilla, lobes; male S2 setae on tergite IX as long wing-retaining setae 2 pairs or more (except as or longer than S1 setae ....................... Hystricothripina with only one pair), tube ......................................... Idolothripinae with or without long setae .......................... Maxillary stylets narrower, width in distal .............................................. Idolothripini half 2–3 (occasionally 3–6) microns in – Metasternum with or without sternopleural diameter, usually with maxillary guides sutures, pelta with or without campaniform or bridge; pelta usually narrow, without sensilla, a pair of wing-retaining setae, tube well-developed lateral lobes; male S2 se- without long setae ................... Pygothripini tae on tergite IX usually short and stout ... ....................................... Phlaeothripinae Key to genera of tribe Idolothripini in Taiwan 1 Tube with significant lateral setae .............. Subfamily Idolothripinae Bagnall 1908 ............................................... Bactrothrips Diagnosis. Macropterous, brachypterous – Tube without significant lateral setae ....... 2 or apterous; female body size median to large, 2 Tergites III–V each with 3 pairs of wing-re- usually brown or dark brown. Head long or taining setae ......................... Mecynothrips squared, usually prolonged in front of eyes; – Tergites III–V each with 2 pairs of wing-re- maxillary stylets broad, width in distal half taining setae ............................................ 3 5–10 microns in diameter, V-shaped or parallel 3 Ventral side of eye longer than dorsal side .. or close together in head; prosternal basantra ........................................ Ophthalmothrips present or absent; forewings if present, with – Ventral side of eye equal to or shorter than Idolothripini of Taiwan 325 dorsal side .............................................. 4 Bactrothrips Karny (Fig. 1) 4 Lateral lobes of pelta connected to center ... Bactrothrips Karny, 1912: 131. Type species: ............................................. Elaphrothrips – Lateral lobes of pelta separated from cen- Bactrothrips longiventris Karny. ter, forming 3 isolated parts; anteroangle of Female. Large, macropterous; head length male mesonotum with spiracular process ..... approximately twice its width, slightly pro- ................................................. Dinothrips longed in front of eyes; setae on head blunt (B) (A) (G) (D) (E) (C) (F) (H) (I) Fig. 1. Bactrothrips species: brevitubus Takahashi (Type male A–F): (A) head; (B) pelta; (C) tergite X; (D) tergite VII; (E) shape of antenna with sense cones on segments III and IV; (F) male tubercles on abdominal segments VI– VIII; (G) pelta of honoris; (H) tubercles of flectoventris; and (I) tubercles of pictipes and B. honoris (the same). 326 台灣農業研究 第 67 卷 第 4 期 or near sharp at apex; maxillary stylets short ........................................... brevitubus and V-shaped; antennae slender, 8-segmented, – Reticles on lower 1/3 of pelta in different segment III with 2, segment IV with 4 sense directions ...................................... honoris cones. Prothoracic basantra weak; metathorac- Takahashi (Figs. ic sternopleural sutures absent; forewing with Bactrothrips brevitubus duplicated cilia. Pelta hat-shaped, depressed 1A–1F) between center and lateral lobes; tergites II– Bactrothrips brevitubus Takahashi, 1935:61–63. VII each with 2 pairs of sigmoid wing-retain- Female. Body length 6–8 mm on slide. ing setae, without neighboring short accessory Color dark brown; antennal segments I and II setae; tube with numerous distinct lateral se- same color as head, III and VI mostly yellow tae. with distal ends greyish brown, segment VI Male. Macropterous, tergite VI with a pair basal half yellow and greyish brown distally, of lateral tubercles, sometimes VII and VIII rest of segments greyish brown; femora brown, either or both with a pair of tubercles, usually tibiae bicolored with brown and yellow: distal smaller. ends of fore tibiae yellow, distal 1/3 of mid More than 40 species were recorded in the tibiae yellow, hind tibiae mostly yellow with world (ThripsWiki 2018). basal 1/4 brown; tube brown. Key to species of Bactrothrips in Taiwan Head length 1.8–2.5 times its maximum width (Fig. 1A); antennae 8-segmented (Fig. (based on male characters) 1E); maxillary stylets V-shaped, in posterior 1 Tubercles on tergites VII finger-shaped ...... 1/4 of head. Forewing with 40–80 duplicated .................................................. brevitubus cilia, number of cilia vary depending on size – Tubercles on tergite VII triangular, not fin- of specimens. Pelta semicircular,