Spalangia impunctata Howard, 1897
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|Spalangia impunctata Howard, 1897|
Spalangia impunctata Howard, 1897: 140–141 ; holotype ♀ (BMNH, examined). Type data: Grenada, Balthazar [Windward side], March 5, 250 ft. [H. H. Smith; 6; W. Indies. 99-331].
Description. Female. Length = 1.2–1.7 mm. Legs dark except basal 3 or 4 tarsal segments yellow. Head in anterior view (Fig. 239) about 1.1–1.3x as high as wide; in dorsal view about 2.0–2.2x as wide as long; in lateral view (Fig. 238) with malar space about 0.8–0.9x eye height and about 1.2–1.4x eye width. Head capsule (Figs 238–240) primarily smooth and shiny as follows: with fine but complete median sulcus extending ventrally to level of lower orbit, sometimes to within slightly elongate-triangular scrobal depression, otherwise upper face and parascrobal region with setae originating from at most minute pinprick-like punctures or sometimes tiny bumps on lower parascrobal region, and with setae extending over smooth inclined surface of scrobal depression; scrobal depression usually with variably finely coriaceous to coriaceous-granular scrobes on either side of very slender, smooth and shiny interantennal region, but sometimes completely sculptured; gena punctate-reticulate to rugose near oral margin and with linear malar sulcus, but otherwise smooth except for setae toward eye; temple punctate similar to face. Antenna (Fig. 246) with scape about 5.9–6.0x as long as wide, the inner (Fig. 248) and outer (Fig. 249) surfaces coriaceous- to reticulate-rugose, though inner surface
Figs 238–245. Spalangia impunctata Howard. 238–240, head: 238, lateral view H ♀, 239, anterior view PR♁, 240, lateral view H♁; 241, PR ♀ mesosoma, dorsal view; 242, H ♀ mesopleuron; 243, PR ♀ propodeum, dorsal view; 244 & 245, scutellum–petiole, posterodorsal view: 244, H ♀, 245, PR♁. Abbreviations, H = Hawaii, PR = Puerto Rico.
Figs 246–251. Spalangia impunctata Howard. 246 & 247, antenna: 246, H ♀, 247, PR♁; 248 & 249, H ♀ scape: 248: inner view, 249, outer view; 250 & 251, ♁ scape: 250, PR, inner view, 251, H, outer view. Abbreviations, H = Hawaii, PR = Puerto Rico.
often with somewhat finer sculpture; pedicel about 1.7–2.3x as long as apical width and about 2.8–3.8x as long as fu 1; funicle with fu 1 slightly transverse, about 1.2–1.3x as wide as long, fu 2 strongly transverse and ring-like, at least 2x as wide as long, and all subsequent segments strongly transverse, with fu 7 about 1.7–2.0x as wide as long; clava about 1.8–2.1x as long as wide.
Pronotal collar in lateral view (Fig. 238) only very low convex behind neck and with circumpronotal band anterolaterally, but anteriorly smoothly rounded to neck; smooth and shiny without cross-line posteriorly, and conspicuously and uniformly setose except bare mediolongitudinally (Fig. 241). Mesoscutal median lobe (Fig. 241) smooth and shiny except for transverse band of coriaceous-alutaceous sculpture near midlength and setae posterior to sculptured region. Axillae (Fig. 241) shiny with setae originating from at most pinprick-like punctures. Scutellum (Figs 241, 244) flat and shiny, sparsely setose laterally with setae originating from at most pinprick-like punctures; frenum (Figs 241, 244) with frenal line very broadly interrupted, consisting only of 1 or 2 punctures laterally. Mesopleuron (Fig. 242) quite shiny and finely sculptured as follows: pectal region shiny and bare except for 1 posteroventral seta; acropleuron finely, longitudinally striate-strigose and differentiated from pectal region by horizontal stria ventrally; subalar and episternal scrobes shallow depressions connected by a shallow, linear furrow; upper mesepimeron finely, obliquely alutaceous to obliquely carinate-alutaceous, but lower mesepimeron more coriaceous-alutaceous to partly smooth and shiny; upper and lower mesepisternum smoothly merged except for short anterior sulcus connected to vertical subalar depression, without complete transepisternal line or ventral line of setae, with upper mesepisternum at most only very finely and obscurely coriaceous. Fore wing hyaline; mediocubital fold with 3 or 4 setae but basal cell bare. Propodeum (Figs 241, 243, 244) without postspiracular sulcus except for sculptured region posteriorly adjacent to metacoxal flange; callus variably distinctly reticulate-rugose anterolaterally but with smooth and shiny longitudinal band extending from anterior margin adjacent to spiracle, the smooth band continuous with smooth and shiny propodeal panel posterior to spiracle; plical region with Y- shaped paramedian crenulate furrows delineating distinct, flat, shiny, lanceolate median band, and furrows united into single crenulate line over about posterior half; supracoxal band a singe crenulate line to lateral margin of nucha.
Petiole (Fig. 244) about 1.3–1.4x as long as medial width; punctate-reticulate; bare. Gaster smooth and shiny or one or more tergites in part very finely coriaceous.
Male. Length = 1.1–2.2 mm. Antenna (Fig. 247) with scape about 6.0–6.7x as long as wide with similar sculpture (Figs 250, 251) as female; pedicel about 1.9–2.2x as long as wide; flagellum with setae much shorter than width of segment; funicle with fu 1 about 0.9–1.2x as long as wide and about 0.4–0.6x as long as pedicel, and subsequent funicular segments all transverse, with fu 7 about 1.4–1.7x as wide as long. Otherwise similar to female except as follows. Head in anterior view about 1.0–1.2x as high as wide; in lateral view (Fig. 240) with malar space about 0.7–0.9x eye height and about 0.9–1.3x eye width. Fore wing with 1–5 setae on mediocubital fold. Propodeum (Fig. 245) with complete postspiracular sulcus separating propodeal panel from callus; callus sometimes more or less uniformly finely roughened, and sometimes with median lanceolate band rugulose or very narrow (essentially an irregular median carina). Petiole (Fig. 245) about 1.5–1.8x as long as medial width.
Material examined. Neotropical (7♀, 7♁). GRENADA: (♀ holotype) . MEXICO: San Jose del Boca , Lower California, 19.IV.49, Correa coll. (3♀, 6♁ USNM) . PANAMA: Canal Zone , Ancon, 10.XI.21, J. Zetek, Z-1563, pars. of Araecerus fasciculatus (De Geer) (1♀, 1♁ USNM) . PUERTO RICO: Piedras , 13.III.63, E.F. Legner, em. ex cow dung (1♀ USNM) . Unknown locality: So. Amer. Par. Lab., 25.VIII.45, no. 1336.27 (1♀ USNM) .
Distribution. Likely a circumtropical species because in addition to the type material of S. lanaiensis and other specimens from Hawaii, I have seen individuals that I at least tentatively identify as S. impunctata from Australia: Queensland (UCDC), Cape Verde Island (USNM), India (USNM), Japan (USNM), Mauritius (USNM), Thailand (UCDC) and Borneo: Sarawak (UCDC).
Biology. The host record of the coffee bean weevil, Araecerus fasciculatus (DeGeer) ( Coleoptera : Curculionidae ) is perplexing unless the specimen was actually reared through an unrealized tachinid primary parasitoid. UCRC has a series of both sexes from Honolulu, Hawaii, reared from unidentified Drosophila puparia, March and July, 1918. A female from Japan that was intercepted at Jacksonville, Florida, has the information “soil w. potatoes”, and a female from India is labelled “ Dacus cuc . mat.” (undoubtedly Dacus cucurbitae Coquillett ( Trypetidae )). The Mauritius record is based on two males that were laboratory reared in Florida on S. calcitrans , from material obtained from a laboratory colony in Reduit, Mauritius.
Recognition. I include S. impunctata as one of seven species in the drosophilae species group as discussed under S. drosophilae . Unlike other drosophilae -group species (e.g. Figs 54, 122) the mesopleuron of S. impunctata is only quite finely sculptured and shiny (Fig. 242) similar to subpunctata -group species, though individuals of S. drosophilae and S. leiopleura also have quite a finely sculptured (Fig. 122) or at least not an obliquely striate-strigose upper mesepisternum (Fig. 266). Females of S. impunctata and S. drosophilae are very similar except for propodeal sculpture. Females that I identify as S. impunctata lack a complete postspiracular sulcus and have the callus lateral to the spiracle smooth and shiny like the propodeal panels so that the smooth regions are continuous behind the spiracle (Fig. 243). All New World males of S. impunctata I have seen have a complete postspiracular sulcus and the smooth band lateral to the spiracle is sometimes obscure, though the propodeal callus is always less conspicuously sculptured (Fig. 244) than for males of S. drosophilae (Fig. 120). However, males of S. impunctata are readily differentiated from males of all other drosophilae - group species by flagellar structure. They have a comparatively short, clavate flagellum (Fig. 247) with a subquadrate to oblong fu 1 that is obviously shorter than the pedicel. Other Spalangia males usually have the first funicular segment obviously longer than the pedicel (e.g. Figs 60, 126). Antennal structure of male S. impunctata is additionally similar to females (cf. Figs 246, 247) because fu 2 –fu 7 are obviously transverse and the ter- minal segment is quite conspicuously differentiated as a clava. Because of their similar antennal structure the sexes of S. impunctata can quite easily be mistaken for one another. Males of S. drosophilae are readily differentiated both from conspecific females and from males of S. impunctata because they have much more elongate flagellar segments with conspicuously long, semierect setae (Figs 125, 126).
My description of S. impunctata is based only on specimens from the New World and either does not adequately encompass morphological variation for the species or there are sibling species in what I interpret as S. impunctata from elsewhere. I tentatively identify a female from India as S. impunctata based on the combination of an obviously lanceolate median propodeal band and finely sculptured, shiny mesopleuron. However, this female has a complete postspiracular sulcus and mostly punctate-reticulate callus similar to females of S. drosophilae and some S. impunctata males. The two reared males originating from Mauritius also have an unusually long fu 1 compared to other known males of the species, being about 1.4x as long as the pedicel, though the subsequent flagellar segments are similar to other male S. impunctata .
Ashmead (1901) described S. lanaiensis based on both sexes collected in Hawaii. The two female syntypes of S. lanaiensis plus another BMNH female labelled “Hawaii, Honolulu, R.C.L Perkins coll.” are larger than other females of S. impunctata examined from Hawaii or the New World and have a longer flagellum with fu 1 distinctly oblong, fu 2 quadrate or only about 1.5x as wide as long, and the subsequent funicular segments almost quadrate or only slightly transverse, and the clava about 2.7–2.9x as long as wide. Furthermore, the callus lateral to the spiracle is not as smooth as in other observed females and at least the non-syntype female has a distinct postspiracular sulcus (cf. Fig. 244). The slightly infuscate fore wing of the female syntype has a line of at least seven setae on the mediocubital fold and eight setae in a line in the basal cell. The male syntype lacks its head and the principal diagnostic feature for the species, its antennae, but it has quite a smooth and shiny upper and lower mesepimeron and although the wings obscure the sculpture of the callus the propodeum has a distinctly lanceolate median smooth band. Another female I saw from Australia (UCDC) is similar to the female syntypes of S. lanaiensis , but other males and females I have seen from Hawaii (UCRC) are similar to what I interpret as S. impunctata from the New World.
The unique female holotype of S. impunctata lacks its head and antennae, is glued to a point such that its mesopleural sculpture is not clearly visible, and except for the right hind femur and tibia its legs are either in the glue or are missing. The right wings are also mostly missing and the gaster is detached and glued to the point. However, the characteristic propodeal sculpture of females is clearly visible and the left fore wing has six setae on the mediocubital fold. When Howard described the species, he accurately stated that it is “closely related to S. drosophilae ”, whereas Bouček (1963: 475) questionably placed S. impunctata under synonymy with S. haematobiae . This tentative synonymy apparently was based on two BMNH females that are labelled “ St. Vincent, W.I. [West Indies], H.H. Smith” and that bear Z. Bouček identification labels with “? S. impunctata Howard 1896 ” and “ S. impunctata (? = haematobiae Ashm. )”. Both of these females are specimens of S. imitator .
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