Orasema taii, Chien & Heraty, 2018

Chien, Iris & Heraty, John M., 2018, Come and Gone: Description of a New Species of Eucharitidae (Hymenoptera) Attacking Solenopsis (Hymenoptera: Formicidae) in Texas, Insect Systematics and Diversity 2 (1), pp. 1-7 : 2

Orasema taii n. sp.

( Figs 1–23 ) (http://zoobank.org/ urn:lsid:zoobank.org:act:DA294E6D-76C6-4BFC-AFCE-D8EDECBF4C53 )

Diagnosis

Species in the bakeri group are recognized by having seven funicular segments, the prepectus without a carina along the anterior margin, the femora are mostly dark brown, and the petiole in females is only slightly longer than broad (in males up to 2.5× as long as broad). The new species is distinguished from other members of the group ( O. bakeri Gahan , Orasema texana Gahan ) by the following combination of features: clava with a distinct ventral notch separating two apical clavomeres; mesoscutellar disc between frenal line and axillae distinctly longer than broad and with a central median channel that is a more coppery colored than the surrounding dark blue–green frenum; and petiole with a weak anterior carina, no lateral carina, and strongly rugose. The clava is a single completely fused structure in all other bakeri -group species. O. bakeri has reticulate sculpture on the dorsal surface of the petiole, whereas O. taii has areolate-reticulate sculpture ( Fig. 12 ). O. texana Gahan has the mesoscutellar disc between the frenal line and axillae at most as long as broad, scabriculous (not evenly fine reticulate) sculpture dorsally, petiole with dorsal surface relatively flat and reticulate, and in females, it has a prominent dorsolateral carinae that extends the full length of the petiole.

Female: Length 2.37–3.05 mm.

Color:

Head and mesosoma blue green, mesosoma more greenish dorsally and mostly dark blue laterally ( Figs. 10 and 11 ). Scape pale brown; pedicel brown; anellus yellowish brown; flagellum dark brown. Mandible, maxilla, and labium dark brown. Coxae dark blue; femora mostly dark brown to black, tips pale; tibiae yellow. Fore wing hyaline; venation pale brown. Petiole dark blue; gaster brown.

Head:

Head in frontal view subtriangular ( Fig. 3 ); 1.14–1.26× broader than high; face reticulate. Occiput strigate, shallowly emarginate in dorsal view, dorsal margin abrupt; temple present, rounded. Scrobal depression shallow, laterally rounded, reticulate, dorsal scrobal depressions absent; longitudinal groove between eye and torulus absent; eye sparsely setose, appearing bare; interocular distance 1.59–1.88× eye height; malar space 0.74–0.96× eye height; malar depression weakly impressed between mouth and eye margin; supraclypeal area about as long as broad, shorter than clypeus, weakly sculptured; clypeus strongly sculptured; epistomal sulcus narrow but shallow; anterior tentorial pits shallow; anteclypeus distinct, straight. Labrum with four digits ( Fig. 3 ). Mandibular formula 3:2 ( Figs. 3 and 9 ); palpal formula 3:2. Scape not reaching median ocellus. Pedicel small and globose. Flagellum with seven funicular segments ( Fig. 1, F2–8 ); flagellum length 0.96–1.1× head height; anellus disc-shaped; F2 1–1.33× as long as broad, 0.85–1.06× as long as F3; following funicular segments subequal in length, equal in width; clava subconical, with notch ventrally between first and second subsegments.

Mesosoma :

Mesosoma 1.08–1.23× as long as high ( Figs. 4 and 10 ). Mesoscutal midlobe reticulate medially to rugose-reticulate laterally, with minute setae; lateral lobe strigose medially, to longitudinally reticulate laterally; notaulus deep ( Fig. 11 , not). Axilla reticulate medially to rugose-reticulate laterally, dorsally elevated well above scutellum ( Figs. 4 and 10 ); scutoscutellar sulcus narrow, regularly foveate, extending to transscutal articulation medially, axilla broadly divided ( Fig. 11 , ax); scutellar disc slightly longer than broad, finely reticulate medially; frenal line reticulate; frenum reticulate; axillular sulcus anteriorly narrow, broad and foveate posteriorly; axillula reticulate. Propodeal disc broadly rounded, areolate-reticulate, without median carina ( Fig. 5 ); callus areolate-reticulate, bare; callar nib absent. Prepectus areolate-reticulate, triangular dorsally, strongly narrowed ventrally ( Figs. 4 and 10 ). Mesepisternum reticulate laterally, becoming smooth to areolate-reticulate ventrally, broadly rounded anterior to mesocoxa. Upper mesepimeron weakly reticulate; lower mesepimeron areolate-reticulate; transepimeral sulcus weakly impressed. Metepisternum laterally reticulate anteriorly, areolate-reticulate posteriorly. Propleuron convex, weakly reticulate. Postpectal carina prominent. Metacoxa 1.68–1.92× as long as broad and reticulate dorsally, becoming smooth ventrally; metafemur 4.4–5.6× as long as broad, with even cover of short, dense setae; metatibia sparsely setose. Fore wing ( Fig. 13 ) 2.25–2.9× as long as broad, 2.36–2.87× as long as mesothorax; basal cell and speculum bare, costal cell sparsely setose, wing disc moderately setose; marginal fringe relatively long; submarginal vein bare; marginal vein with minute setae; stigmal vein about the same length as postmarginal vein, slightly angled distally; uncus absent; stigma with three clustered sensilla in a straight line and a fourth separated ( Fig. 13 , inset); postmarginal vein 5.0–7.2× as long as stigmal vein. Hind wing costal cell with a broad bare area.

Figures

Figs. 1–7. Orasema taii, female. (1) Antenna (lateral). (2) Flagellomeres F1–3 (lateral). (3) Head (anterior). (4) Mesosoma (lateral). (5) Mesosoma (oblique posterior). (6) Petiole and acrosternite (lateral). (7) Mesosoma and petiole (ventral).

Figs. 8–13. Orasema taii, female. (8) Apex of antenna (lateral). (9) Mandibles (posterior). (10) Mesosoma (lateral). (11) Mesosoma (dorsal). (12) Petiole (dorsal). (13) Fore wing.

Figs. 14–17. Orasema taii. (14) Ovipositor,ventral view. (15) Lateral view of apex of ovipositor stylets.(16) Female pupa, lateral and ventral view. (17) Male pupa, lateral and ventral view of abdomen (inset). Except for inset, pupae are at same scale.

Figs. 18–23. Orasema taii. (18) Section through leaf showing egg within oviposition puncture. (19) Oviposition on Vachellia (Fabaceae). (20) Planidium habitus, dorsal and ventral view. (21) Magnified mandibular area of planidium. (22)Third instar larva. (23) Pupa.