New species of Eretmocerus Haldeman (Hymenoptera: Aphelinidae) parasitizing Crenidorsum turpiniae (Takahashi) and Aleurothrixus floccosus (Maskell) (Hemiptera: Aleyrodidae) from Taiwan Author Shih, Yuan Tung Department of Entomology, National Taiwan University, Taipei, Taiwan; Author Polaszek, Andrew Department of Life Sciences, Natural History Museum, London, UK; Author Dubey, Anil Kumar Forest Entomology Division, Forest Research Institute, Dehradun, India; Author Chen, Shu-Pei Taiwan Agricultural Research Institute, Wufeng, Taiwan Author Yang, Ping-Shih Department of Entomology, National Taiwan University, Taipei, Taiwan; Author Ko, Chiun-Cheng Department of Entomology, National Taiwan University, Taipei, Taiwan; text Journal of Natural History 2015 2015-07-31 50 377 391 http://dx.doi.org/10.1080/00222933.2015.1075622 journal article 21260 10.1080/00222933.2015.1075622 e5971a71-001b-473f-93da-18bd7f3a8274 1464-5262 3991865 Eretmocerus lannae Shih & Polaszek , sp. nov. ( Figures 1 – 3 ) Diagnosis Females of Eretmocerus lannae sp. nov. can be identified by having 6 setae on the mesoscutum; a single seta on each mesoscutal side lobe; a short, pale yellow, cylindrical antennal clava, 4.7 – 5× as long as wide ( Figure 1C ); and prominent frenal arms (circled in Figure 3 ). Description (female holotype ) Length, 0.71 mm . ( Paratypes , 0.61 – 0.73 mm ( n = 10). Colour. Head yellow. Mesosoma pale yellow. Gaster yellow. Antenna pale yellow. Wings hyaline. Legs pale yellow except basal margin of mid and hind femur. Head. Vertex with 12 – 13 pairs of setae. Face and occiput with transverse substrigulate sculpture, interscrobal area vertically substrigulate. Face with 24 – 26 setae. Supraclypeal area with 10 – 12 setae. Clypeus with 3+3 setae, 2 short setae on mid margin. Upper posterior head with 26 – 28 setae, 3 pairs of long and robust setae present in a row across the head. Lower posterior head with 15+14 setae, one short seta on the mid part ( Figure 1B ). Antenna ( Figure 1C ): radicle 3.8× as long as wide; scape 3.7× as long as wide, 1.94× as long as radicle, 1.76× pedicel length, 0.52× clava length; pedicel 2.21× as long as wide, 1.10× as long as radicle, 0.56× scape length. Funicle I trapezoid, dorsal length 0.5× ventral length. Funicle II 1.4x as wide as long. Clava cylindrical, narrowed at apex, 4.9× as long as greatest width, 1.87× scape length, 3.23× pedicel length. Clava with 5 articulated spines. Mesosoma ( Figure 2A ). Mid lobe of mesoscutum with 6 setae, anterior part with cellular reticulate sculpture, remainder with faint elongate reticulations. Side lobe with 1 seta, anterior margins with faint reticulations; axilla with 1 seta, faintly reticulate. Scutellum with 4 setae, anterior pair shorter, 0.87× posterior pair; 2 placoid sensilla placed laterally equidistant from both paired setae, Scutellar reticulation similar to that of mesoscutum. Frenal arms long and exceeding metanotum. Metanotum slightly narrower centrally than propodeum. Propodeum with faint transverse reticulations, central lobe broad and smooth. Wings. Fore wing ( Figure 2D ) 2.42× as long as maximum width of disc. Longest posterior marginal fringe seta 0.24× disc width. Base of wing with 1 seta, distal portion of costal cell with 1 seta. Marginal vein with 2 long setae, 11 – 14 setae present between marginal vein and partial linea calva. Submarginal vein 1.11× as long as marginal vein and 3.13× stigmal vein length. Marginal vein 2.52× stigmal vein length. Legs ( Figures 1D–F ). Mid tibial spur 0.52× basitarsus length. Hind tibial spur 0.52× basitarsus length. Figure 1. Eretmocerus lannae sp. nov. : (A) head, front view; (B) head, posterior view; (C) antenna; (D) fore leg; (E) mid leg; (F) hind leg. Gaster ( Figure 2B ). Gastral tergite I with reticulations on lateral margins; tergites 1 – 6 with paired setae as follows: 1, 1, 1, 2, 2, 2. Syntergum (T7) with 4 setae. Ovipositor somewhat prominent, weakly exserted, 0.86× clava length, subequal to mid tibia; 1.62× scape length. Figure 2. Eretmocerus lannae sp. nov. : (A) mesosoma ; (B) gaster; (C) ovipositor; (D) fore wing. Figure 3. Eretmocerus lannae sp. nov. : mesosoma with frenal arms circled. Male. Unknown. Holotype ♀ (on slide), Taiwan : Dayuan , Taoyuan , ex Aleurothrixus floccosus on Psidium guajava , 20 February 2013 , Y. T . Shih ( NTU ). Paratypes . 10 ♀♀ (on slides), data same as the holotype . ( 1♀ , BMNH ; 9♀ , NTU ) . Distribution Taiwan : Dayuan, Taoyuan . Host Hemiptera : Aleyrodidae : Aleurothrixus floccosus (Maskell) . Remarks The female of Eretmocerus lannae sp. nov. is unusual in having a single seta on the mesoscutal side lobe, a character observed for the first time in the genus Eretmocerus . Generally, Eretmocerus species have 2 – 3 setae on the side lobe. The new species is close to E. trialeurodis Hayat , but differs from it in the length of ovipositor, which is 0.86× clava length and subequal in length to the mid tibia, and in having the mid tibial spur 0.52× the basitarsus, and with fewer setae on the vertex. Eretmocerus lannae sp. nov. is a potential biocontrol agent of A . floccosus ; the parasitoid population was found to be abundant. Although A. floccosus was infesting heavily both the golden dewdrop ( D. repens ) and guava ( P. guajava ), only the population on guava was parasitized by E. lannae . The reason for this selective host preference could be plant secondary metabolites, or possibly that the population of A. floccosus on golden dewdrop secretes more wax than the guava population, creating unfavourable conditions for parasitization. Etymology The species name lannae is derived from ‘lanna’ a Latin word for ‘ lobe ’ , reflecting the prominent frenal arms.