Encarsia singhiellae Shih & Polaszek, 2015

Ko, Chiun Cheng, Shih, Yuan Tung, Schmidt, Stefan & Polaszek, Andrew, 2015, A new species of Encarsia (Hymenoptera, Aphelinidae) developing on ficus whitefly Singhiella simplex (Hemiptera, Aleyrodidae) in China and Taiwan, Journal of Hymenoptera Research 46, pp. 85-90 : 86-89

Encarsia singhiellae Shih & Polaszek sp. n.

Figs 1-9 , 10-15

Description of female.

Colour: Head yellow, antenna yellow, slightly darker towards apex. Mesosoma yellow except following light brown: pronotum, posterior margin of mesoscutum, anterior margin of scutellum, axillae and sides of propodeum. Metasoma yellow except T5 dark brown in strong contrast. Base of T1, and T4, infuscate centrally. Fore wing slightly infuscate below marginal vein. Legs yellow.

Morphology: Mandibles each with three small teeth. Stemmaticum with five robust setae and reticulate surface sculpture. Antennal formula 1,1,4,2. F1, F2, F3 approximately equal in length, with any of the three antennomeres the longest in different specimens. Pedicel with two robust setae dorsally. F4 0.9 times F1 (0.85 in holotype); F5 0.7-0.9 × F1 (0.73 in HT); F6 0.8-1.0times F1 (0.9 in HT); funicle length 2.5times clava length (2.3 in HT). F1-F6 with the following numbers of multiporous plate sensilla: F1:0; F2:2; F3:2; F4:3; F5:3 F6:3. Mid lobe of mesoscutum with 4 or 5 pairs of setae, 1 lateral pair and 3-4 centrally (one central seta unpaired in holotype); side lobes with three setae. Scutellar sensilla closely placed, separated by less than the maximum width of one sensillum. Distance between posterior pair of scutellar setae 2 times distance between posterior pair (2.1 times in HT). Fore wing 2.8 times maximum width of disc (2.84 in HT). Marginal fringe 0.26 times maximum width of disc (0.25 in HT). Submarginal vein with 3 setae; marginal vein anteriorly with 7-9 setae (8+9 in HT). Basal cell with 9-15 setae (11+12 in HT). Tarsal formula 5-5-5. Mid tibial spur 0.56 times corresponding basitarsus. Mid tibia with a prominent spine-like seta apically. Metasomal tergites with the following numbers of setae: T1: 0, T2: 2, T3: 2, T4: 2, T5: 4, T6: 4, T7: 4. Ovipositor 1.2 times mid tibia; 2nd valvifers 3.8 times third valvulae (3.7 in HT).

Male.

Unknown.

Material examined.

Holotype female (NHM) on slide, labelled "TAIWAN: Taoyuan, Kuanyin (25.034°N, 121.113°E), 07 July 2011, ex Singhiella simplex on Ficus microcarpa Y.T. Shih col. Holotype Encarsia singhiellae Shih & Polaszek"; paratypes: 9 females, same data as holotype (NHM, NTU). CHINA: Fujian, Xiamen (24.481°N, 118.089°E), 6.x. 2010 ex Singhiella simplex on Ficus microcarpa , J Huang, A Polaszek, Z-H Wang col. (1 female, FAFU).

Species group placement.

The close proximity of the scutellar sensilla, coupled with three setae on the submarginal vein might suggest placement of the new species in the E. strenua group, but the shape of the stigma vein indicates that this placement would be incorrect. E. strenua group species have a distinct constriction between the marginal and stigmal veins. DNA analysis of the 28S D2 region places E. singhiellae sp. n. far away from the monophyletic E. strenua group, in an assemblage that includes E. tricolor Foerster, E. tachii (Polaszek & Hayat), and E. mineoi Viggiani (S. Schmidt, unpublished data). Encarsia singhiellae is therefore currently unplaced with respect to any known species group of Encarsia . The sequence has been deposited in GenBank under accession number KT279403.

In the key to Chinese Encarsia species ( Huang and Polaszek 1998), E. singhiellae sp. n. keys to E. noyesana Huang & Polaszek, 1998. It can be easily distinguished from that species by the three setae on the submarginal vein (two in E. noyesana ); 2-segmented clava (3-segmented in E. noyesana ); and the distinct colour pattern of the metasoma.

Host.

Singhiella simplex (Singh) ( Hemiptera : Aleyrodidae ).

Remarks.

Encarsia singhiellae sp. n. is not closely related to any known Encarsia species, either in the Oriental Region or elsewhere. It has several unusual characters as follows: antenna with two robust setae on the pedicel, and F1 having distinct sculpture; anterior apex of mid tibia with one distinct long spine-like seta. The following character states place the new species in the genus Encarsia : fore and hind tarsi five-segmented, eight antennomeres (excluding radicle), scutellum with two pairs of setae, marginal vein longer than submarginal vein, stigmal vein very short and postmarginal vein absent.

It is the first recorded parasitoid of Singhiella simplex in Asia, and appears to show a high degree of host specificity, as there are no host records from other whitefly species. The species is currently only known from the type locality.

Figures

Figures 1 - 9. E. singhiellae sp. n.: 1 Head, frontal view 2 Head, back view 3 Fore leg 4 Mid leg 5 Hind leg 6 Dorsal mesosoma 7 Dorsal metasoma 8 Antenna 9 Fore wing.

Figures 10 - 15. E. singhiellae sp. n.: 10 Apex of antenna 11 Detail of compound eye 12 Articulation of tibia and femur, fore leg 13 Ventral habitus 14 Mouth 15 Articulation of tibia and femur, mid leg.