Aprostocetus madhucae Singh, 2022

Singh, Sudhir, Kumar, Arvind & Kaneria, Manish, 2022, Description of five new eulophid species (Hymenoptera: Eulophidae) associated with leaf vein galls of Madhuca longifolia (J. Koenig) (Sapotaceae) in India, Zootaxa 5129 (1), pp. 1-36 : 12-17

2. Aprostocetus madhucae Singh sp. nov.

( Figs 33–50 )

Diagnosis. FEMALE. Body yellow with light to dark brown areas especially at pronotum, mesoscutum, scutellum propodeum and middle of gaster. Head triangular; toruli placed below the middle of face, slightly above a line joining the lower margins of the eyes; subantennal grooves deep and not reaching clypeal margin. Antenna with scape extending beyond the vertex; with one anellus; funicle 3-segmented, all funicle segments long; club appearing twosegmented, apical segment very small. Forewing with marginal vein 3.2× as long as stigmal vein; postmarginal vein about a third of stigmal vein. Propodeal spiracle its own diameter away from the anterior margin of propodeum, rim of propodeal spiracles entirely visible; paraspiracular carina sharp; median part of propodeum between paraspiracular carinae prominently sculptured. Ovipositor slightly longer than gaster length; ovipositor sheaths slightly exserted, by about half the length of postcercale.

MALE. Similar to female except that the body is whitish yellow. Toruli placed their own length above a line joining the lower margins of the eyes. Antennal scape with a pale brown ventral plaque at distal six-sevenths, covering 75% of ventral margin; funicle 4-segmented, without whorl of longer setae at base, F1 shortest; club 3-segmented. Forewing with marginal vein 2.5× as long as stigmal vein. Digitus of genitalia with one long digital spine, paramere with 2 setae.

Description. FEMALE ( Figs 33–38 , 45–48 ). Body size 1.55 ± 0.14 mm (n = 21, range 1.30 to 1.83 mm). Holotype 1.70 mm (Card-mounted).

Color/Sculpture. Body ( Fig. 33 ) deep yellow dorsally and pale yellow ventrally, with following areas suffused with light to dark brown: post gena, occipital area around foramen; pronotum (except lateral whitish areas); anterior middle of mesoscutum, middle and anterior margin on lateral lobes of mesoscutum; lateral panel of axilla; anterior middle of scutellum; posterior lateral margins of metanotum; callus and inner area along paraspiracular carina of propodeum; all pleura (except yellow femoral depression of mesopleuron); mesosternum; gaster dorsally (except pale yellow oval area spread medially on first to third segments). Antenna with scape off-white, with anterior third and dorsal margin brownish, pedicel like scape with basal half light brown, flagellum dark brown with basal ventral margins and sensillae off white. Legs yellow; in darker specimens metacoxae dorsally suffused with brown. Wings hyaline, veins light yellowish brown. Outer sheath of ovipositor ventrally suffused with light brown, exserted part of ovipositor sheaths dark brown. Head ( Fig. 45 ) sparsely setose, setae off-white; with longitudinal reticulate sculpture, more prominent on lower face; parascrobal area dorsally with 2 rows of setae; vertex with 14–16 setae; scrobes deep; inter-antennal area with a pair of setae at the base; subantennal grooves deep and arc like (diverging out) almost reaching a point between anterior tentorial pit and malar sulcus; malar sulcus slightly curved; lower face between malar sulci with 7 pairs of setae; eyes with small setae. Mesosoma ( Fig. 46 ): pronotum with squamiform reticulate sculpture with about 4 transverse rows of white setae; mesoscutum and scutellum silky with fine and delicately engraved longitudinal reticulation; midlobe of mesoscutum without median line, with 3 adnotaular setae (some specimens with 2 setae) in a single row; lateral lobe of mesoscutum with 3–4 setae on the lateral and posterior margins. Scutellum with finer reticulation than midlobe of mesoscutum, with 2 pairs of setae outside submedian groove, anterior pair longer, placed at the distal two-thirds near or almost touching submedian groove, posterior pair at the distal scutellar margin, almost between submedian and sublateral grooves; a distinct transverse subapical groove running all along the posterior margin. Dorsellum with faint reticulate sculpture as on middle area of pronotum. Propodeum with prominent median carina diverging out posteriorly to meet carina on posterior margin, paraspiracular carina sharply developed; area between median and paraspiracular carinae with strong reticulate sculpture; callus with 2 setae, anterior seta stronger and 2× as long as posterior seta. SMV of forewing with 2 dorsal setae, basal 2× as long as proximal seta. Setae on body pale brownish yellow with brown base.

Structure. Head as wide as mesosoma (425); in frontal view ( Figs 34 , 45 ) triangular, 1.2× as wide as high (425: 342), 1.7× as wide as frontovertex (425: 250); POL 1.4× OOL (106: 74); toruli placed slightly below the middle of face, about one-fifth of their own length above a line joining the lower margins of the eyes; malar space about 0.7× as long as eye length (126: 180), mouth 1.2× as wide as malar space (216: 180). Antenna ( Figs 35 , 47 ) with 1 anellus; scape 3.5× as long as wide (206: 58); pedicel about 2.1× as long as wide (85: 40); F1 longest, 1.4× as long as pedicel length (118: 85) and 2.7× as long as wide (118: 43), F2 2.3× as long as wide (108: 46), F3 2.2× as long as wide (100: 46). Clava 3-segmented; C1 1.5× as long as wide; C2 1.4× as long as wide (78: 54); C3 ( Fig. 36 ) indistinctly separated from C2, cone-like, as wide as long (length includes terminal spine) (42: 43), suture between C2 and C3 oblique; terminal spine 0.5× as long as C3 width (21: 42), without apical seta.

Mesosoma 1.4× as long as wide. Pronotum conical, half as long as mesoscutum (128: 260). Mesoscutum about 1.8× as long as scutellum (266: 149). Scutellum about 1.7× as wide as long, 3× dorsellum length; submedian lines further from each other than from sublateral line, enclosing a space about 2× as long as wide. Dorsellum 2.2× as wide as long. Propodeum medially 1.2× as long as dorsellum. Forewing ( Fig. 37 ) with speculum present, 2.3× as long as wide (1318: 563); marginal vein narrowly longer than costal cell, about 3.3× as long as stigmal vein (332: 101); postmarginal vein about a third of stigmal vein (30: 101). Mesotibial spur 0.5× as long as basitarsus.

Gaster ( Fig. 33 ) slightly wider than mesosoma; 1.3× as long as mesosoma; petiole indistinct; Gt7 5× as long as exserted part of ovipositor, postcercale 0.4× of Gt7. Hypopygium reaching about middle of gaster. Ovipositor narrowly longer than gaster length; exserted part of ovipositor sheaths half as long as postcercale ( Fig. 48 ).

MALE. ( Figs 39–44 , 49, 50 ). Body size 1.31 ± 0.14 mm (freshly killed in alcohol, n = 14, range 1.00 to 1.50 mm).

Color/Sculpture. Similar to female except that the color is whitish yellow ( Fig. 39 ) and brown markings are not as prominent. Antenna ( Fig. 41 ) scape and pedicel pale yellow; flagellum pale brown to dark brown from base to apex, with whorls of long setae.

Structure. Head as wide as mesosoma (465); in frontal view ( Figs 40 , 49 ), 1.1× as wide as high (424: 366), 1.7× as wide as frontovertex (424: 248); POL 1.6× OOL (117: 70); toruli placed at middle of face, about their own length above a line joining the lower margins of the eyes; malar space about 0.7× as long as eye length (131: 187); malar sulcus straight; mouth width 1.8× malar space (154: 131). Antenna ( Fig. 41 ) with one anellus; scape 2.5× as long as wide (448: 175); ventral plaque covering 0.8× length of ventral margin of scape; pedicel about 1.6× as long as wide (167: 100); funicle 4-segmented, F1 shortest about 1.6× (180: 114), F2 about 2.2× (219: 100), F3 2.3× (208: 92) and F4 2.3× (219: 95) as long as wide. Clava 3-segmented, C1 2.1× (176: 83), C2 1.9× (207: 109) and C3 1.7× (154: 93) as long as wide. Terminal spine 0.6× as long as C3 width (59: 111), without apical seta.

Mesosoma ( Fig. 50 ) 1.4× as long as wide (605: 421). Mesoscutum 1.3× as long as scutellum (236: 184); scutellum about 1.3× as wide as long (184: 236), about 4.4× dorsellum length (184: 42); sublateral lines twice further from each other than submedian lines from each other, the latter enclosing a space about 2.5× as long as wide; dorsellum with convex posterior margin, 2.7× as wide as long. Propodeum 1.6× as long as dorsellum (67: 42). Forewing ( Fig. 42 ) 2.3× as long as wide (1185: 515); marginal vein narrowly shorter than costal cell (322: 324), 2.5× as long as stigmal vein (324: 126). Mesotibial spur as long as basitarsus.

Gaster ( Fig. 39 ) as long as mesosoma; genitalia ( Figs 43, 44 ): aedeagus 0.8× as long as phallobase length (244: 292), phallobase 4.5× as long as wide (292: 65), digitus with one long digital spine.

Variation. There is variation in size for both sexes, see above. Both sexes show great variation in the brown patterns, as per description above.

Material examined. Holotype: ♀, card mounted; INDIA: Uttarakhand, Dehradun, New Forest ; 31.i to 10.ii.2017; Sudhir Singh ; ex. leaf vein galls of Madhuca longifolia (Koenig) (Sapotaceae) . Deposited in NFIC-FRI, Accession No. H-22038.

Paratypes: 71 ♀, 52 ♂, same data as holotype : 29 ♀, 23 ♂ on 12 cards; 3 ♀ and 6 ♂ dissected and mounted on 3 slides; 39 ♀ and 23 ♂ whole mounted on a slide. Deposited in NFIC-FRI, Accession No. P-22038 .

Host. Associate of gall on Madhuca longifolia , parasitoid of Selitrichodes madhucae sp. nov.

Distribution. India: Uttarakhand.

Etymology. Named after the associated tree genus Madhuca .

Comments. In the key to subgenera of Aprostocetus by Graham (1987) Aprostocetus madhucae sp. nov. does not key out clearly to any of the subgenera but can most suitably be assigned to subgenus Aprostocetus on the basis of males having whorls of long setae at the base of funicle segments. However the following set of characters would take it to subgenus Ootetrastichus: Basitarsus of front and hind legs not longer than second tarsal segment; forewing 2.3x as long as wide, tip of marginal vein beyond the middle of wing length, speculum small, SMV with 2 dorsal setae; propodeal spiracle circular with rim completely exposed and separated from metanotum by its own diameter; midlobe of mesoscutum without median line; mesosoma long, about 1.5x its width, pronotum 0.4x (in female) and 0.25x (in male) of mesoscutum; ovipositor slightly exserted. Male antennal funicular segments sub-equal in length, scape with ventral plaque mainly in distal half. Conversely, some characters like subcubital line of setae reaching basal vein, propodeal spiracle very small, antenna always with 4 anelli are in disagreement with Ootetrastichus .

In the key to Aprostocetus species of Indian sub-continent by Narendran (2007), A. madhucae runs to sankarani (couplet 42) but differs from it in the following characters (characters given in brackets are those of A. sankarani ):

Female. Body with many brownish spots, see description (body mainly pale yellow; flagellum brownish; following parts brown: a dot on pronotum just above spiracle, with short vertical line, two small dots on either side of base of forewing, a conspicuous cross-band on Gt4). Antenna with F1 2.7×, F2 2.3× and F3 2.2× as wide as long (F1 3×, F2 2.7× and F3 2.5× as wide as long); basal segment of club shorter than combined length of distal 2 segments (basal longer). Mesosoma 1.4× as long as wide (1.3×); pronotum 0.5× mesoscutum length (0.2×); scutellum 1.7× as wide as long (1.5×); median area of scutellum 2× as long as wide (1.7×); dorsellum 2.2× as wide as long (3×); propodeum medially 1.2× as long as dorsellum (slightly longer). Forewing disc margin smoothly curved (margin apically flattened); SMV with 2 dorsal setae (1); marginal vein as long as costal cell (1.2×), 3.3×as long as stigmal vein (4.4×).

Male. Similar to female, for color see description (brownish color more extensive than in female). Scape swollen in the middle, 2.56× as long as wide (slender, 3.6×); ventral plaque 1.6× as long as scape width (1×), 0.7× scape length (0.3×) and covering 0.8× length of ventral margin of scape (placed at middle of distal half of ventral margin of scape); F1 with base distinctly swollen (almost cylindrical with slight swollen base); setae in whorls shorter than 2 funicle segments combined (longer); basal club segment 1.2× as long as middle one (1×).

Figures

FIGURES 33–38. Aprostocetus madhucae Singh sp. nov., female: 33, dorsal body view showing color variations among the specimens; 34, head in frontal view; 35, antenna; 36, distal segments of club showing apical spine; 37, forewing; 38, ovipositor.

FIGURES 39–44. Aprostocetus madhucae Singh sp. nov., male: 39, dorsal body view showing color variations among the specimens; 40, head in frontal view; 41, antenna; 42, forewing; 43, genitalia; 44, distal part of genitalia showing digitus spines.

FIGURES 45–50. Aprostocetus madhucae Singh sp. nov. 45–48, female: 45, head in frontal view; 46, mesosoma in dorsal view; 47, antenna; 48, distal segments of gaster showing cercal setae and exserted part of ovipositor; 49–50, male: 49, head in frontal view; 50, mesosoma in dorsal view.