Encarsia boswelli (Girault)

Schmidt, Stefan & Polaszek, Andrew, 2007, The Australian species of Encarsia Förster (Hymenoptera, Chalcidoidea: Aphelinidae), parasitoids of whiteflies (Hemiptera, Sternorrhyncha, Aleyrodidae) and armoured scale insects (Hemiptera, Coccoidea: Diaspididae), Journal of Natural History 41 (33 - 36), pp. 2099-2265 : 2138-2139

17. Encarsia boswelli (Girault)

( Figures 59–62 )

Coccophagus boswelli Girault 1915 [238], p 49. Holotype ♀, Australia, Queensland, Cooktown (QMBA, type no. T. 2929, examined).

Coccophagus filius Girault 1915 [238], p 48. Holotype ♀, Australia, Queensland, Gordonvale (Cairns) (QMBA, type no. T. 2924, examined). Synonymy by Polaszek and Hayat 1990, p 1.

Coccophagus boswelli Girault : Dahms 1983, p 145.

Prospaltella boswelli (Girault) : Viggiani 1985c, p 237.

Dirphys boswelli (Girault) : Hayat 1989b, p 288. Polaszek and Hayat 1990, p 1.

Encarsiella boswelli (Girault) Polaszek and Hayat 1992, p 181 ; Huang and Polaszek 1996, p 1652.

Encarsia boswelli (Girault) : Schmidt and Polaszek 2007, p 81 .

Diagnosis

Female. Colour: head brown. Mesosoma brown, metasoma dark brown. Antenna with radicle, scape, pedicel, and first and second funicle segments pale brown, contrasting with white third funicle; clava dark brown, paler at each end. Fore wing infuscate below marginal vein. Legs yellow-white except hind coxa which is dark brown.

Morphology [measurements of holotype in square brackets]: maxillary palp twosegmented. Antennal formula 1,1,3,3, clava very distinct. Pedicel slightly shorter than F1 (0.84–0.88) [0.84]. F1 (2.46–2.67) [2.67] times as long as its maximum width, subequal in length to F2 and F3. Flagellomeres with the following numbers of sensilla: F1: 2, F2: 2, F3: 2, F4: 3–4, F5: 4–5, F6: 4–5 and with sensory area. F1–F3 cylindrical and similar in shape and size, F4 conical and subequal in length to preapical and apical segment. Midlobe of mesoscutum with about 6–14 setae, side lobes with two to three setae each. Scutellar sensilla separated by approximately five times the maximum width of a sensillum. Distance between anterior pair of scutellar setae smaller than distance between posterior. Fore wing 2.7 times as long as width of disc. Basal cell with two to five setae. Submarginal vein with two setae, marginal vein anteriorly with 7–11 setae. Longest setae of marginal fringe 0.22– 0.23 [0.22] times as long as width of disc. Apical spur of midtibia slightly longer than half the length of the corresponding basitarsus (0.59–0.64) [0.64]. Basitarsus of middle leg ventrally with stout setae. Tergites on each side with the following numbers of setae: T1: 0, T2: 1, T3: 1, T4: 1, T5: 2, T6: 2, T7 with four setae. Ovipositor longer than midtibia (1.13–1.23) [1.23] and two times as long as clava. Third valvula about 0.36 times as long as second valvifer.

Male. No males of the species were collected in the study area. For a description of E. boswelli males from elsewhere see Polaszek and Hayat (1990, p 3).

Species group placement. E. boswelli group.

Distribution. Australia: Queensland. Palaeotropical.

Host. Not reared in the study area, but elsewhere the species has been reared from the following hosts ( Polaszek and Hayat 1990, 1992): Heteroptera: Plataspidae (eggs): Brachyplatys vahlii (F.), Megacopta cribraria (F.).

Comments

Unlike all other known Encarsia species , which have a three-toothed mandible, the mandible of E. boswelli has four teeth. This species is also unusual for an Encarsia because it is an egg parasitoid of black stink bugs (Heteroptera: Plataspidae ), and it is the only known obligatory egg parasitoid in the Coccophaginae ( Polaszek 1991) , except for males of E. porteri which develop in eggs of Lepidoptera ( Hunter et al. 1996) . The generic placement of E. boswelli has long been debated and it has only recently been placed in Encarsia as part of a revisionary treatment of the Encarsia noyesi species group (formerly Encarsiella ) based on molecular and morphological evidence ( Schmidt and Polaszek 2007).

Figures

Figures 59–62. Encarsia boswelli (Girault), holotype female. (59) Overall view of type specimen. (60) Antenna. (61) Fore wing. (62) Mesoscutum in lateral view.