Elasmus curticornis, Gunawardene & Taylor, 2012

Gunawardene, Nihara R. & Taylor, Christopher K., 2012, New records of Elasmus (Hymenoptera, Eulophidae) species from Barrow Island, Western Australia, Journal of Hymenoptera Research 29, pp. 21-35 : 24-25

Elasmus curticornis sp. n. Fig. 4

Holotype.

1 ♀, Barrow Island, northern sector HDD, N. Gunawardene, C. Taylor, 14-24 March 2011, sticky trap.

Paratype.

1 ♀, barge landing, N. Gunawardene, C. Taylor, 14-24 March 2011, suction.

Etymology.

From the Latin curtus, shortened, and cornu, a horn, in reference to the short antennae of this species, as well as by analogy to the similar species Elasmus brevicornis Gahan 1922.

Description.

Body length. 1.48-2.13 mm.

Coloration. Head and mesosoma blackish with green sheen, except antenna, mandibles and base of tegula cream, dorsellum translucent. Gaster primarily orange, except T1 black, T4 with or without posterolateral dark spots meeting medially, posterior part of T5 to end of gaster black or T5 with transverse dark stripe and T6 to end of gaster dark, S6 to end of gaster black. Leg 1 with base of coxa black, remainder yellow except basal infuscation on femur; legs 2 and 3 each with coxae black except distal ends yellow, trochanters yellow, femora mostly brown except proximal and distal ends yellow, tibiae and tarsi yellow.

Head. Slightly narrower than mesosoma; in dorsal view 2.0 times wider than long; in frontal view slightly (1.1 times) wider than high. Vertex and frons with dense piliferous punctures, with interspaces on frons subequal to diameter of punctures. Ocellar triangle about twice as long as wide, POL:OOL 2.3-2.5:1, OD:OOL 0.3-0.4:1, OC:OD 0.8-0.9:1. Compound eye 1.5-2.1 times as high as wide in lateral view; inner margins of compound eyes straight to slightly concave, frons minimum width 0.7 times total head width. Malar space 0.4-0.5 times eye height; lower margin of toruli 2.1-2.5 times their diameter from lower margin of face, about in line with lower margin of eyes. Each mandible with seven teeth.

Antenna ( Figure 4B, C ). Scape 0.5 times as long as pedicel and flagellum combined, lengths of scape and of pedicel and flagellum combined 0.6-0.7 times and 1.0-1.2 times compound eye height; pedicel 1.4-1.8 times as long as wide, 1.3 times length of funicle 1; funicle 1 subtriangular, 0.9-1.0 times as long as wide; funicle 2 and 3 each shorter than (0.8 times and 0.8-0.9 times length of, respectively) funicle 1, funicle 2 0.6-0.7 times and funicle 3 0.6 times as long as wide; clava 1.4-1.5 times as long as wide, 2.3-2.8 times as long as and 1.3 times as wide as funicle 3, clava 3 triangular.

Mesosoma ( Fig. 4D, E ). 1.5-1.7 times longer than wide. Mesoscutum 0.9 times as long as wide, densely covered with piliferous punctures; posterior margin of mesoscutum concave. Scutellum 0.9 times as long as wide, finely reticulate, setae absent except elongate setae at anterolateral and posterolateral corners, anterior and posterior pairs of setae of similar length, posterior setae not extending beyond apex of dorsellum. Dorsellum length 0.7 times basal width.

Wings. Hyaline. Forewing ( Fig. 4F, G ) 1.4-1.5 times length of head and mesosoma combined, 3.3-3.6 times as long as wide; isolated subcubital line of setae present; postmarginal vein subequal in length to stigmal vein. Hind wing 0.9 times length of forewing, 5.1 times as long as wide.

Legs. Mid femur with stout apical posterolateral seta 0.2-0.3 times length of tibia. Hind tibia with dorsal pattern of black setae demarking four diamonds anterolaterally and three diamonds posterolaterally.

Gaster. Gaster 0.8-1.1 times length of head and thorax combined, 2.1-2.3 times as long as wide, not produced; posterior margin of T6 straight.

Comments.

The distinctive quadrate antennae of this species, with all funicular segments broader than long, distinguish it from most other species of Elasmus except the Asian species Elasmus brevicornis Gahan 1922 and Elasmus philippinensis Ashmead1904 and the Australian Elasmus concinnus Riek 1967. Elasmus philippinensis has a brown-black flagellum, with only the scape yellowish ( Ashmead 1904). Elasmus brevicornis and Elasmus concinnus both have notably less extensive light coloration on the gaster. The gaster of Elasmus concinnus is dorsally almost entirely dark except for a light cross-band at the apex of T2 ( Riek 1967), while that of Elasmus brevicornis is light dorsally at the apex of T1, T2 and sometimes T3 ( Mani and Saraswat 1972; Verma et al. 2002; Yefremova and Strakhova 2010) and may sometimes be entirely dark brown to black ( Verma et al. 2002). In contrast, the gaster of Elasmus curticornis is light from the apex of T1 to T4 or T5. Laterally, the gasters of Elasmus brevicornis and Elasmus concinnus are light over at most a third ( Mani and Saraswat 1972; Riek 1967) while that of Elasmus curticornis is light over at least two-thirds. Also, Elasmus brevicornis has POL 1.5 times OOL ( Yefremova and Strakhova 2010), as opposed to about 2.5 times in Elasmus curticornis . Elasmus concinnus has the flagellum dark above and the first claval segment distinctly shorter than the third funicle ( Riek 1967); Elasmus curticornis has the flagellum more evenly pale, and the first claval segment and third funicle are subequal in length.

Figures

Figure 4. Elasmus curticornis, holotype. Lateral view A close-up of head B antenna, diagram (setae omitted) C dorsal view D dorsal view, diagram (E) forewing F forewing diagram showing setal pattern G.