Aprostocetus chilophagae Yefremova and Yegorenkova, 2018

Johnson, Paul J., Yefremova, Zoya A., López, Juan Manuel Perilla & Yegorenkova, Ekaterina N., 2018, Aprostocetus chilophagae new species (Hymenoptera: Eulophidae) from South Dakota, with taxonomic notes on A. bromi (Kostjukov) and A. nebraskensis (Girault), Zootaxa 4514 (4), pp. 473-486 : 480-481

Aprostocetus chilophagae Yefremova and Yegorenkova , new species

( Figs. 18–24 )

Holotype ♀, U.S.A., South Dakota, Brookings Co. Watertown, 44°15' N, 96°40'W, reared from Chilophaga virgati (Cecidomyiidae) emerged from Panicum virgatum (Poaceae) , reared 14.v.2013, V. Calles Torrez (USNM).

Paratypes: 2 ♀, 1 ♂, with the same labels as holotype (USNM, TAUI); 2 ♀, U.S.A., South Dakota, Brookings Co. Food Farm. 44°22'N, 96°47'W reared from Chilophaga virgati (Cecidomyiidae) emerged from Panicum virgatum (Poaceae) sample 22.vi.2014, emerged 1.vii.2014, M. Perilla.

Diagnosis. Both sexes have a distance between submedian lines 1.4 times as distance between submedian and lateral line, mesoscutum with 3 adnotaular setae, dorsellum as long as propodeum, propodeal callus with 2 setae. Female antenna ( Fig. 22 ) with F1 2.3–2.5 times as long as broad and 1.1 times as long as F2. Clava 3.6–3.8 times as long as broad. Forewing 2.4 times as long as broad; MV 3.3 times as long as STV. Male antenna ( Fig. 23 ) with scape with ventral plaque about 0.4 time total length. F1 2.0 times as long as broad, and 1.2 times as long as F2, F2 2.7 times as long as broad, F3 2.7 times as long as broad and equal to F2, F4 2.5 times as long as wide. Funicular segments with whorled setae; whorls on F1 reaching beyond middle of F2. Forewing MV 3.5 times as long as STV.

Description. Female: Body length 2.8–3.5 mm. Body brown. Head brown, radiculus of antenna yellow; flagellum mostly brown with scape yellow ventrally; eye reddish. Mesosoma mostly brown with yellowish transscutal line, submedian scutellar lines and dorsellum laterally. Tegula yellow. Mesopleural suture yellow or yellow brownish. Leg with coxa brown, femur brown over basal two-thirds; trochanter yellow, tibia yellow; tarsus yellow with last two tarsomeres brown, hind tarsus with all brown tarsomeres. Gaster brownish.

Head 1.1 times as broad as long. Eyes 1.3 times as long as broad. Malar space 1.5 times as height of eye. Malar sulcus straight. Mouth width as broad as malar space. Face smooth; POL 1.2 times as OOL. Antenna ( Fig. 22 ) inserted at lower level of ventral margin of eyes; scape 3.4 times as long as broad; pedicel 2.2–2.4 times as long as broad and 1.8 times shorter than scape; funicle with four anelli and three funicular segments decreasing in length, F1 2.3–2.5 times as long as broad and 1.2 times shorter as pedicel, F2 2.10–2.25 as long as broad and 1.1 shorter than F1, F3 1.8–2.0 times as long as broad and 1.2 times shorter than F2, clava 3-segmented with F11 (terminal spine), 3.6–3.8 times as long as broad and 2.0–2.1 times as long as F3.

Mesosoma 1.3 times as long as broad and 1.6 times, shorter than gaster. Pronotum 4.2 times as broad as long. Mesoscutum 1.3 times as broad as long, with 3 adnotaular setae, median line distinct, alutaceous. Scutellum 1.25 times as broad as long, setae placed just below middle. Distance between submedian lines 1.4 times as long as distance between submedian and lateral lines. Dorsellum as long as propodeum medially. Propodeum 6.0 times as broad as long, smooth between median carina and postspiracular sulcus; spiracles placed near frontal margin of propodeum; callus with 2 setae.

Forewing 2.5 times as long as broad; SMV with 4 setae; MV 1.3–1.4 times as long as SMV; STV 2.3 times shorter than MV; MV with 10–12 setae; speculum small, extending along 0.3 times MV, closed posteriorly. Hindwing apically broadly rounded.

Gaster 2.4–2.5 times as long as broad, smooth. Last tergite 1.4 times as long as broad. Sheaths of ovipositor slightly protruding.

Male. Body length 2.4–2.6 mm. Color as in female. Antenna ( Fig. 23 ) with scape 2.9 times as long as broad, with ventral plaque about 0.40 length of scape, situated above the middle; pedicel 1.8 times as long as wide; flagellum with three laminar anelli and four funicular segments and three-segmented clava; F1 1.7 times as long as broad, and 1.3 times as long as F2; F2 2.5 times as long as broad; F3 2.7 times as long as broad and as long as F2; F4 2.5 times as long as wide, clava 3-segmented, 5.7 times as long as broad and 2.2 times as long as F4. Funicular segments with whorled setae; whorls on F1 reaching beyond of middle of F2, whorls of F2 reaching about to apex of F3, whorls F3 reaching middle of F4, whorls of F4 reaching basal of C2, whorls of C1 reaching half of length of C3 and F11 (terminal spine). Forewing ( Fig. 16 ) 2.5 times as long as broad; relative lengths of venation: SMV 1.7 times shorter than MV, MV 3.5 × as long as STV; SMV with 4 and MV with 13 setae. Gaster 2.2 times as long as broad. Genitalia, digitus with 2 spines ( Fig. 4 ).

Distribution. U.S.A., South Dakota.

Host. Chilophaga virgati (Cecidomyiidae) on Spartina pectinata (Poaceae) .

Comments. Aprostocetus chilophagae is similar to A. nebraskensis and differs by the following characters: color of mesopleuracic suture and dorsellum yellow, first flagellomere 2.6 times as long as broad, propodeum as long as dorsellum, presence of 3 adnotaular setae on the mesoscutum, callus with 2 setae, length to width ratio of the forewing (2.3–2.5 times), SMV with 3–4 setae MV with 13 setae; distance between submedian lines/submedian and sublateral lines 1.4 times (1.8 times in A. nebraskensis ), last tergite 1.4 times as long as broad (1.8 times in A. nebraskensis ). Female gaster 2.5 times as long as broad (1.7 times in A. nebraskensis ).

Other parasitoids reared from C. chilophagae are Trichacis rufipes Ashmead (Platygastridae) that was found as a co-parasitoid of the new species on C. virgati , and a Centrodora sp. ( Aphelinidae ) that is probably a hyperparasitoid. It is unclear at this time whether the Centrodora sp. is actually associated with eggs or larvae of A. chilophagae , T. rufipes , or another species ( Polaszek 1991).

Figures

FIGURES 18–24. Aprostocetus chilophagae: 18, female, lateral view; 19, female, dorsal view; 20, male, lateral view; 21, male, genitalia

FIGURES 16–17. Male, Aprostocetus nebraskensis: 16, body, dorso-lateral view (South Dakota); 17, mesoscutellum, dorsellum and part of propodeum, dorsal view (South Dakota).

FIGURES 1–4. Antennae of female Aprostocetus bromi (Kostjukov) and A. nebraskensis (Girault): 1, A. bromi (Kostjukov) (Paratype, ZISP); 2, A. bromi reared from Stenodiplosis bromicola on Bromus inermis (South Dakota); 3, A. bromi reared from Stenodiplosis spartinae on Spartina pectinata (South Dakota); 4, Antenna of A. nebraskensis (Girault) (Type USNM).