Macreupelmus Ashmead

Macreupelmus Ashmead

Macreupelmus Ashmead, 1896: 7 (key), 14 (description). Type species: Macreupelmus brasiliensis Ashmead, by monotypy and original designation.

Description. FEMALE. Body comparatively large, about 4–6 mm in length excluding strongly exerted ovipositor sheaths; mostly dark with variably extensive green, blue, purple and/or reddish-violaceous lusters, excluding legs (e.g. Figs 6, 7, 15, 24). Head in lateral view meniscoidal to low-subtriangular with lower face abruptly angled to longer, low-convex to flat frontovertex, and anterior and posterior surfaces converging dorsally to narrowly rounded vertex (e.g. Figs 29, 40, 112); scrobes bare but otherwise entirely setose with white setae on anterior and lateral surfaces and at least some dark setae on vertex, the setae on lower face, interantennal prominence and parascrobal region slightly lanceolate and therefore more conspicuous compared to more hairlike setae on frontovertex (e.g. Figs 8, 20, 36, 37); scrobal depression reticulate to reticulate-rugulose and comparatively deep ventrally near torulus, with abrupt but rounded parascrobal margin near torulus and depression shallowed dorsally to indistinctly indicated dorsal margin separated from anterior ocellus (e.g. Figs 8, 20, 36, 37); parascrobal region with inner margin sinuately recurved toward inner orbit beside torulus such that lower parascrobal region broader ventrally than at level of inner orbit above level of interantennal prominence and in frontal view scrobal depression bell-shaped (e.g. Figs 8, 20, 36); frons with variably distinct and elongate sulcus between anterior ocellus and scrobal depression (e.g. Figs 25, 38, 57); OOL obviously less than MPOD. Eyes densely setose (e.g. Figs 8, 20, 36). Mandibles bidentate with small, acute ventroapical tooth and broad, truncate to slightly incurved dorsoapical margin (Figs 88, 101, 102). Antenna clavate with scape variably extensively pale apically and/or clava partly to entirely pale, but pedicel and funicle dark (e.g. Figs 21, 29, 74); scape robust-subcylindrical to distinctly compressed-rectangular; fl1 (anellus) at least as long as wide and slightly shorter than pedicel, and fl2–fl4 all distinctly longer than quadrate to transverse fl5–fl8; pedicel and basal 4–6 flagellomeres with whitish seta dorsally under at least some angles of light (e.g. Figs 21, 29, 112); and fl4 to clava with inconspicuous multiporous plate sensilla in two or more rows.

Prothorax with longer, dense black setae dorsally on pronotum (Fig. 13: prn), on propleuron (Fig. 13: ppl), prosternum (Fig. 13: pst), procoxa and posterior surface of profemur (Fig. 13: pfm); pronotum divided medially, collar in dorsal view linear medially and transverse-triangular or lunate laterally (e.g. Figs 42, 80), and in lateral view neck abruptly inclined to collar (e.g. Figs 6, 112). Mesonotum (e.g. Figs 42, 80) reticulate-punctate to longitudinally reticulate-strigose; mesoscutum depressed posteromedially behind low-convex, triangular anteromedial lobe and between low-convex lateral lobes; lateral lobes carinate posteriorly and mesoscutum often also variably distinctly carinate mediolongitudinally from apex of anteromedial lobe partly through posteromedial depressed region; mesoscutum with white to dark setae mesally but setae white at least along lateral and posterior margins; scutellar-axillar complex with dark setae on axillae and at least anteriorly on scutellum. Prepectus with lateral surface coarsely reticulate and densely setose with dark hairlike setae (e.g. Figs 13, 79), and vertically subdivided by differentiated line of thinner cuticle (flexion line) within about basal third to half (Fig. 13: pfl). Mesopectus with white setae ventrally between acropleural sulci and on acropleuron anteriorly; acropleuron reticulate-rugose with region of minute sculpture mesally. Macropterous; fore wing entirely setose except sometimes costal cell bare dorsally; basal cell hyaline or sometimes infuscate basally, but with dark hairlike setae; disc infuscate from base of parastigma to level about equal with apex of postmarginal vein, with dark lanceolate setae to about level of apex of stigmal vein anterior to medial fold and more hairlike dark setae apically and usually posteriorly, but with posterobasally directed hyaline region with white hairlike setae behind marginal vein (Fig. 9: 1), often more or less hyaline region with white or dark setae along posterior margin of wing opposite anterior hyaline region (Fig. 9: 2), and sometimes with slender hyaline region with white setae extending from submarginal vein near base of parastigma along basal fold and mediocubital fold basally (Fig. 9: 3) or sometimes only on mediocubital fold and/or membrane distal to basal cell (Figs 45, 54). Legs mostly dark brown to orangish, but middle leg with femur apically and trochantellus often mostly white or at least paler than rest of femur (trochantellus dark at least ventrobasally, e.g. Figs 10, 104), and hind leg with apex of coxa, trochanter and trochantellus white, and femur dorsoapically and tibia basally paler or white (e.g. Figs 14, 27, 59); mesofemur with posterior surface setose only within about apical half (e.g. Figs 28, 50) or additionally with region of longer setae submesally (e.g. Figs 60, 83, 91); mesotibia with oblique groove apically between tibial spur and base of tarsus and with row (Figs 32, 61, 84, 111) or patch (Figs 22, 48, 100) of apical pegs in region over base of tibial spur; mesotibial spur dark to orangish but not white; mesotarsus concolorous with tibia and with single row of dark pegs on either side of basal four tarsomeres. Propodeum with callus elongate-rectangular, low-convex, and entirely setose with white setae (e.g. Figs 41, 58); plical region variably long, with panels sculptured medially (e.g. Figs 26, 41, 58, 94, 114). Gaster (e.g. Figs 47, 62) lanceolate with sides diverging to about level of cerci; dark except for yellowish to hyaline syntergal flange, the basal terga dorsally mostly dark brown but at least penultimate tergum and sometimes apical three terga variably distinctly green to blue or purple, and other terga often with some metallic luster laterally; Gt1–Gt3 or Gt4 distinctly emarginate (Figs 47, 62) and comparatively weakly sculptured, meshlike coriaceous to at most inconspicuously and very shallowly reticulate, Gt5 usually more distinctly meshlike reticulate, but Gt6 reticulate or reticulate-rugose (e.g. Figs 23, 56, 70) to granular (Figs 86, 95); hypopygium on either side with elongate-oval, dense patch of white setae forming reflective surface (e.g. Fig. 14); syntergum with syntergal flange, the flange longer than wide and of similar length or longer than syntergal surface anterior to flange. Ovipositor sheaths extending for distance equal to about one-third to one-half length of gaster, usually mostly yellow but at least paler than gaster and with variably darker brown region subapically (e.g. Figs 6, 15, 24).

MALE. Unknown.

Biology. Hosts are unknown for any species although individuals are possibly parasitoids of insect eggs because species of Anastatus Motschulsky, Mesocomys Cameron, and Oozetetes have similarly structured bidentate mandibles and are known egg parasitoids. However, most species of Zaischnopsis Ashmead have tridentate mandibles and at least some are indicated also as egg parasitoids (Gibson 2005).

Recognition and relationships. Females of Macreupelmus uniquely possess an oblong region of dense, slightly lanceolate white setae that form a reflective patch on either side of the hypopygium (Fig. 14). Although this differentiates females from those of all other eupelmine genera, females of other genera can have the hypopygium variably densely setose (e.g. Fig. 12). Consequently, it is not the presence or absence of setae but simply the relative density that is autapomorphic. Some Zaischnopsis females have similar though obviously less densely setose hypopygial regions (Fig. 12) in addition to very similar color patterns of the fore wings (cf. Figs 4, 9), legs (cf. Figs 1, 6), and other body parts, including similarly long, yellowish ovipositor sheaths relative to a generally dark body (cf. Figs 1, 2 with 6, 7), plus otherwise variably similar structures and sculptural and setal patterns (cf. Figs 1–3 with 6–8). Such females closely resemble those of Macreupelmus, but in addition to the hypopygial setal difference they have tridentate mandibles (cf. Figs 3, 88), white setae on at least the propleuron and prosternum (cf. Figs 11, 13: ppl, pst), the posterior surface of the mesofemur completely setose (cf. Figs 5, 10), the prepectus bare (cf. Figs 11, 13), and a different scrobal depression structure in which the inner margin is evenly directed to the inner orbit rather than sinuately emarginate along the inner orbit so that the depression is ∩-shaped (Fig. 3; Gibson 1995, figs 67–72) rather than bell-shaped (Fig. 8; Gibson 1995, figs 27, 28).

Gibson (1995) noted the similarities between Macreupelmus and some Zaischnopsis females, but hypothesized that Macreupelmus formed a monophyletic group with nine other genera (Gibson 1995, fig. 520), including Anastatus, based on common possession of similarly structured bidentate mandibles (Gibson 1995, character 1, state 2a). However, after examining species from around the world, Gibson (1995) noted that females of some species of Zaischnopsis intergrade morphologically with those of Anastatus, whereas others intergrade with those of Brasema Cameron. He thus hypothesized that the three genera could represent grades of structure and that Zaischnopsis could be rendered paraphyletic by Anastatus (Gibson 1995, figs 515, 518) or by both Anastatus and Brasema (Gibson 1995, fig. 518). Likewise, the similarity between Macreupelmus and some Zaischnopsis females could indicate that Macreupelmus represents nothing more than a relatively small, monophyletic group of Neotropical species that are united by a few conspicuous secondary modifications, but which renders the much more speciose and cosmopolitan genus Zaischnopsis paraphyletic. If species are egg parasitoids their bidentate mandibular structure might have evolved for functional reasons independently of similarly structured mandibles in other genera that are mostly egg parasitoids. Although males of Macreupelmus remain unrecognized, they likely are similar to females in having bidentate mandibles and thus may remain unrecognized within Anastatus if they possess similar flagellar structures as for Anastatus males (Gibson 1995). The absence of any species being reared to date at least indicates species are not parasitoids of economically important or commonly reared taxa.

Species differentiation. The recognized species of Macreupelmus are differentiated primarily by different combinations of the following features: propodeal plical region medially short (e.g. Figs 26, 58) to long (e.g. Figs 19, 41); Gt6 (penultimate gastral tergum) granular (Figs 86, 95) or variably coarsely and distinctly reticulate to reticulate-imbricate (e.g. Figs 23, 56); mesotibial apical pegs arranged in row (Figs 32, 61, 84, 111) or patch (Figs 22, 48, 100); leg color patterns; and presence or absence of different regions of white setae on the fore wing in addition to the large hyaline region behind the marginal vein (Fig. 9: 1), including a slender hyaline region extending from the submarginal vein near the parastigma along the basal and mediocubital folds (Fig. 9: 3) or only along the mediocubital fold and/or disc anterior to the mediocubital fold distal to the basal cell (Figs 45, 54), and a more or less hyaline region with white or dark setae along the posterior margin of the wing opposite of the anterior hyaline region (Fig. 9: 2).