Female. Head and mesosoma dark brown to black; legs with procoxa yellowish white, meso- and metacoxae dark brown to black, femora yellowish white, protibia yellowish white, mesotibia yellowish white with center greyish, metatibia dark grey to black with base pale; metasoma with base, apex, and venter yellow, remainder brown; antenna white to yellowish white; F3 1.3–1.7 times as long as broad; club 3.2 times as long as broad. Male similar except procoxa grey; pro- and mesofemur sometimes with darkened center; metasoma brown with base and apex yellow; scape dark greyish brown with greyish yellow distal tip, swollen in center, maximum width 3× distal end width, with three to five volcano-shaped secretory pores in a single line on ventral surface, pedicel greyish yellow, third funicle more than 2 times as long as broad, club 3.9 times as long as broad.

Female (Figs 2, 4, 6, 8, 10, 11, 12, 13).

Body length. 0.77–0.93 (Holotype 0.90 mm).

Head. (Figs 2, 8) Head 1.3× as broad as high in frontal view, about as broad as mesosoma; frontovertex width 0.4× of head width, 1.2× as long as broad, and 0.8× as broad as scape length; posterior ocelli 1.0× their diameter from eye margin, 3× their diameter from one another, and 0.33× their diameter from occipital margin; mandible with 2 acute teeth and a broad truncate surface below the teeth, antenna as in Fig. 8 with scape 4.8× as long as broad, pedicel 2.2× as long as broad, F1 anneliform, 1.7× as wide as long, F2 1.2× as broad as long, F3 1.6–1.7× as long as broad, club 3.2× as long as broad, 2.7× times as long as F3, and with 6–7 longitudinal sensilla.

Mesosoma. (Figs 4, 6, 13) Mesoscutum and scutellum with fine reticulate sculpture, longest diameter of reticulations approximately twice the diameter of the scutellar sensilla, interior of reticulations with fine, granulate surface (visible only in slide-mounts under high magnification); mid-lobe of mesoscutum with 2 pairs of long setae and about 40 short setae, side lobes each with 2 long and 1 short setae; scutellum with 2 pairs of long setae and two sensilla directly posterior to the anterior pair of setae, scutellar sensilla slightly posterior to middle of scutellum; mesotibial spur 0.8× mesobasitarsus; metatibial spur 0.6× metabasitarsus.

Fore wing. (Fig. 10) 2.3× as long as broad; costal cell with 1 complete row of dorsal setae and 2 rows of ventral setae, the posterior row extending from under the proximal end of the marginal vein almost to stigma, costal cell 1.2× longer than marginal vein; submarginal vein with 5–6 setae; marginal vein with 10 setae along the margin; stigmal vein short with stigma rounded; delta region proximal to linea calva with one complete line of 13–15 setae and 2–6 additional setae in angle with marginal vein, linea calva with no dorsal setae at its posterior edge; wing distal to linea calva with dense, evenly spaced, dorsal setae and much smaller ventral setae.

Hind wing. (Fig. 11)4.3× as long as broad, marginal fringe 0.26× wing width.

Metasoma. (Figs 4, 6, 12) 1.2× as long as mesosoma; ovipositor inserted at middle of metasoma, slightly exerted distally, 1.3× as long as meso- and metatibiae; third valvula one-third length of ovipositor.

Color. (Figs 2, 4, 6) Head and mesosoma dark brown to black; legs with procoxa yellowish white, meso- and metacoxae dark brown to black, femora yellowish white, protibia yellowish white, mesotibia yellowish white with center greyish, metatibia dark grey to black base pale, tarsi pale brown with tips and metabasitarsus greyish brown; metasoma with base (T1 and T2), apex, and venter yellow, remainder brown; antennae yellowish white; compound eyes burgundy, and ocelli red in life, both silver-colored in dried specimens.

Male (Figs 1, 3, 5, 7, 9, 14). Similar to female except:

Head. (Figs 1, 7) Antenna with scape swollen in middle, 3.4 as long as broad, maximum width 3× distal end width, with 3–5 volcano-shaped secretory pores in line on ventral surface, pedicel 2.1× as long as broad, F1 anneliform, 1.8× as wide as long, F2 1.5× as broad as long, F3 2.0× as long as broad, club 3.9× as long as broad, 2.1× as long as F3, and with 4–6 longitudinal sensilla.

Metasoma. (Figs 3, 5, 14) About the same length as mesosoma, phallobase of genitalia including digiti 4.5× longer than broad, digiti about twice longer than broad and with two apical denticles.

Color. (Figs 1, 3, 5) Legs with procoxa grey, pro- and mesofemora sometimes with darkened centers; metasoma brown with base and apex yellow; scape dark greyish brown with greyish yellow distal tip, pedicel greyish yellow.

(card-mounted, deposited in USNM, USNM ENT 00703637).“China: Liaoning, Xiuyan | 40°18'N, 123°14'E | 11.vii.2007, K. Hoelmer || ex: Aphis glycines | on: soybean | plots 1/3, 2007/007 || From Lab Culture | USDA-ARS-BIIRU | Newark, Delaware”

(USNM, TAMU, BMNH). 30 card-mounted and 4 slide-mounted ♀♀, 14 card-mounted and 4 slide-mounted ♂♂ with same data as holotype. 13 card-mounted and 4 slide-mounted ♀♀ and 9 card-mounted and 3 slide-mounted females: China, Liaoning, Xiuyan, 40°20'N, 116°6'E, 12.vii.2007, K. Hoelmer, ex: Aphis glycines on: soybean, plot 2, 2008/008, from Lab Culture, USDA-ARS-BIIRU, Newark, Delaware, all bearing TAMU accession numbers.

In the field, Aphis glycines is the only known host. In laboratory experiments, Aphelinus glycinis parasitizes Aphelinus glycines and closely related species in the genus Aphis.

This species is named for the host from which it was collected. The species epithet is a noun in genitive case.

Aphelinus glycinis is closest to Aphelinus engaeus and Aphelinus ficusae Prinsloo and Neser based on our matrix of traits (Table 2). Aphelinus glycinis differs from Aphelinus engaeus in having elongated third funicle segments in males and females, and it differs from Aphelinus ficusae in having an ovipositor more than 1.2× as long as the mesotibia and grey procoxa in males. It also differs from these species in its aphid hosts and geographical distribution. Aphelinus glycinis is a specialist on Aphis species close to Aphis glycines, but Aphelinus engaeus is reported from Schizaphis graminum (Rondani) and Sitobion ochnearum (Eastop) and Aphelinus ficusae was reared from an undetermined aphid on Ficus sycomorus (Prinsloo and Neser 1994). Furthermore, Aphelinus glycinis was collected in northeastern China, whereas Aphelinus engaeus and Aphelinus ficusae have been reported only from South Africa.

Females. Head and mesosoma dark brown to black; legs with coxae dark brown to black, profemur dark grey with pale apex, mesofemur dark grey to black, metafemur white, protibia white with pale greyish base, mesotibia dark grey to black with pale base and apex, and metatibia dark grey to black with pale base; metasoma yellowish brown with base and apex yellow; antennae yellow with basal half of scape and pedicel sometimes greyish; F3 quadrate; club 2.8 times as long as broad. Males similar except scape swollen in middle, 3× broader in middle than at distal end, with 2 or 3 volcano-shaped secretory pores; scape dark yellowish grey, pedicel pale greyish yellow; club 3.3 times as long as broad.

Female (Figs 16, 18, 20, 22, 24, 25, 26, 27).

Body length. 0.75–0.94 (Holotype 0.87 mm).

Head. (Figs 16, 22) Head 1.2× as broad as high in frontal view, about as broad as mesosoma; frontovertex 0.4× head width and as broad as scape length; posterior ocelli 0.5× their diameter from eye margin, 3.0× their diameter from one another, and 0.33× their diameter from occipital margin; mandible with 2 acute teeth and a broad truncate surface below the teeth; antennae as in Fig. 21 with scape 4.8 longer than broad, pedicel 1.8× as long as broad, F1 anneliform, F2 1.5× as broad as long, F3 quadrate, club 2.8× as long as broad and 3.3× times longer than F3, with 4–6 longitudinal sensilla.

Mesosoma. (Figs 18, 20, 27) Mesoscutum and scutellum with fine reticulate sculpture, longest diameter of reticulations approximately twice the diameter of scutellar sensilla, interior of reticulations with fine, granulate surface (visible only in slide-mounts under high magnification); mid-lobe of mesoscutum with 2 pairs of long setae and 35–40 short setae, side lobes each with 2 long and 1 short seta; scutellum with 2 pairs of long setae, pair of scutellar sensilla directly posterior to the anterior pair of setae and slightly posterior to middle of scutellum; mesotibial spur equal in length to mesobasitarsus; metatibial spur 0.5× metabasitarsus.

Fore wing. (Fig. 24) 2.2× as long as broad ; costal cell with 1 row of dorsal setae and two rows of ventral setae, the posterior row extending from under the proximal end of the marginal vein almost to stigma, costal cell 1.1× as long as marginal vein; submarginal vein with 5 setae, marginal vein with 10 setae along the anterior margin; stigmal vein short with stigma rounded; delta region proximal to linea calva with one complete line of 13–15 setae and 2–6 additional setae in angle with marginal vein, linea calva with no setae at its posterior edge; wing distal to linea calva with evenly spaced, dense dorsal setae and much smaller ventral setae.

Hind wing. (Fig. 25)3.9× longer than broad, marginal fringe 0.23× wing width.

Metasoma. (Figs 18, 20, 26) 1.4× as long as mesosoma; ovipositor inserted at middle of metasoma, slightly exerted distally, 1.3× longer than metatibia and mesotibia; third valvulae one-third the length of ovipositor.

Color. (Figs 16, 18, 20) Head and mesosoma dark brown to black; legs with coxae dark brown to black, profemur dark grey with pale apex, mesofemur dark grey to black, metafemur white, protibia white with pale greyish base, mesotibia dark grey to black with pale base and apex, and metatibia dark grey to black with pale base; metasoma yellowish brown with venter of T1 and apex yellow; antennae yellow sometimes with basal half of scape and pedicel greyish yellow; compound eyes dark burgundy and ocelli red in life, both silver-colored in dried specimens.

Male (Figs 15, 17, 19, 21, 23, 28). Similar to female except:

Body length. 0.66–0.78 mm.

Head. (Figs 15, 21) Antenna with scape swollen in center, 3.1× as long as broad, maximum width 3× width at distal end, with 2–3 volcano-shaped secretory pores in single line on ventral surface, pedicel 1.8× as long as broad, F1 subquadrate, 1.1× as broad as long, F2 shorter, 1.4× as broad as long, F3 trapezoidal, 1.1× longer than width at apex, 1.5× as long as wide at base, club 3.3× as long as broad, with 4 longitudinal sensilla.

Metasoma. 0.7× length of mesoma

Color. (Figs 15, 17, 19) Scape dark yellowish grey, pedicel pale greyish yellow, base of metasoma pale brown and with yellow region at apex smaller.

(card-mounted, deposited in USNM, USNM ENT 00763638). “China, Daxing (Beijing) | 39°48'N, 116°28'E | 10.ix.2005, K. Hoelmer || ex: Aphis glycines | on: Rhamnus sp. | 2005/005 || From Lab Culture | USDA-ARS-BIIRU | Newark, Delaware”

(USNM, TAMU, BMNH). 33 card-mounted and 6 slide-mounted females, 19 card-mounted and 3 slide-mounted males with same data as holotype. 9 card-mounted and 2 slide-mounted females, 6 card-mounted and 2 slide-mounted males: China: Daxing (Beijing), 39°48'N, 116°28'E, 10.iv.2004, W. Meikle coll., ex: Aphis glycines on Rhamnus sp., 2004/008, from lab culture, USDA-ARS-BIIRU, Newark, Delaware.

In the field, Aphis glycines is the only known host. In laboratory experiments, Aphelinus rhamni parasitizes Aphelinus glycines and closely related species in the genus Aphis, and rarely Rhopalosiphum padi L. and Schizaphis graminum.

This species is named for the primary host plant of the aphid species from which it was collected. The species epithet is a noun in genitive case.

Aphelinus campestris and Aphelinus gossypii are the closest described species to Aphelinus rhamni based on our matrix of traits (Table 2). Aphelinus rhamni differs from both species in having a more elongate club and in coloration of the metatibia. Aphelinus rhamni has a much narrower host range than Aphelinus gossypii, which is reported from at least 18 species of aphids in 10 genera and two tribes, including species which Aphelinus rhamni does not parasitize in laboratory experiments.

Females. Head and thorax dark brown to black; legs with coxae dark brown to black, profemur dark grey with distal half pale, mesofemur dark grey to black, metafemur pale yellowish white, protibia pale yellowish white to somewhat fuscous, mesotibia dark grey to black with distal half pale, and metatibia dark grey to black with pale base; metasoma dark brown with base and apex yellow; antennae yellow; F3 quadrate. Males similar except scape swollen in middle, 2.0× as broad in middle than at distal end, with two or occasionally three circular secretory pores in the middle of a shallow depression on ventral surface, scape dark yellowish grey with distal half yellow, pedicel greyish yellow.

Female (Figs 30, 32, 34, 36, 38, 39, 40, 41).

Body length. 0.80–0.93 (Holotype 0.93 mm).

Head. (Figs 30, 36) Head 1.3× as broad as high in frontal view, about as broad as mesosoma; frontovertex 0.4× head width and as broad as scape length; posterior ocelli approximately their own diameter from eye margin, 5× their diameter from one another, and 0.5× their diameter from occipital margin; mandible with two acute teeth and a broad truncate surface below the teeth, ventral tooth sometimes not distinct; antennae as in Figs 30 and 36 with scape 4.0× as long as broad, pedicel 1.6× as long as broad, F1 anneliform, F2 1.4× as broad as long, F3 subquadrate or very slightly broader than long, club 3.75× as long as broad and 3.5× longer than F3, with 7–8 linear sensilla.

Mesosoma. (Figs 32, 34, 41) Mesosoma and scutellum with fine reticulate sculpture, longest diameter of reticulations approximately 2–3× diameter of scutellar sensilla; interior of reticulations with fine, granulate surface (visible only in slide-mounts under high magnification), mid-lobe of mesoscutum with 2 pairs of long setae and about 40–60 short setae, side lobes each with 2 long and 1–2 short setae; scutellum with 2 pairs of long setae; pair of scutellar sensilla approximately equidistant from anterior and posterior pairs of long setae; mesotibial spur 1.1× mesobasitarsus; metatibial spur 0.6× metabasitarsus.

Fore wing. (Fig. 38) 2.2× as long as broad; costal cell with 1 row of dorsal setae and 2 rows of ventral setae, the posterior row extending from under the distal end of the submarginal vein almost to stigma, costal cell 1.3× as long as marginal vein; submarginal vein with 5 setae; marginal vein with 12 setae along the anterior margin; stigmal vein short with stigma rounded; delta region proximal to linea calva with one complete line of 12–13 setae and 2–5 additional setae in angle with marginal vein, linea calva with no setae at its posterior edge; wing distal to linea calva with evenly spaced, dense dorsal setae and much smaller ventral setae.

Hind wing. (Fig. 39) 3.9× as long as broad, marginal fringe 0.26× wing width.

Metasoma. (Figs 32, 34, 40) 1.1× as long as mesosoma; ovipositor inserted at basal third of metasoma, slightly exerted distally, 1.4× as long as metatibia or mesotibia; third valvula 0.28× length of ovipositor.

Color. (Figs 30, 32, 34) Head and mesosoma dark brown to black; legs with coxae dark brown to black, profemur dark grey with distal half pale, mesofemur dark grey to black, metafemur pale yellowish white, protibia pale yellowish white to somewhat fuscous, mesotibia dark grey to black with distal half pale, and metatibia dark grey to black with pale base; metasoma dark brown with base and apex yellow; antennae yellow; compound eyes dark burgundy, ocelli red in life, both silver-colored in dried specimens.

(Figs 29, 31, 33, 35, 37, 42). Similar to female except:

Body length. 0.68–0.81 mm.

Head. (Figs 29, 35) Antenna with scape swollen in center, 3.3× as long as broad, maximum width 2× distal width, with 2 or 3 circular, secretory pores in the middle of a shallow depression on ventral surface, pedicel 2.0× longer than broad, F1 and F2 1.4× broader than long, F3 rectangular, 1.3× as long as wide at apex, club 3.2× as long as broad, with 3–4 longitudinal sensilla.

Metasoma. (Figs 31, 33, 42) 1.5× length of mesoma.

Color. (Figs 29, 31, 33) Scape dark yellowish grey with distal half yellow, pedicel greyish yellow.

Holotype female (card-mounted, deposited in USNM, USNM ENTO 00763639). “Korea, Gyeongsangnam Province, Miryang |35°30'N, 128°44'E | 11.viii.2009, K. Hoelmer || ex: Aphis glycines | on: soybean | 2009/011 || From Lab Culture | USDA-ARS-BIIRU | Newark, Delaware”

(USNM, TAMU, BMNH). 13 card-mounted and 3 slide-mounted ♀♀ and 9 card-mounted and 5 slide-mounted ♂♂ with same data as holotype.

None.

In the field, Aphis glycines is the only known host. In laboratory experiments, Aphelinus coreae parasitizes Aphelinus glycines and other species in the genus Aphis, and occasionally Rhopalosiphum padi and Schizaphis graminum.

This species is named for its country of origin. The species epithet is a noun in genitive case.

Aphelinus campestris and Aphelinus gossypii are the closest described species Aphelinus coreae based on our matrix of traits (Table 2). Aphelinus coreae differs from both species in having a more elongate club in females and in coloration of the scape and mesotibia. Like Aphelinus rhamni, Aphelinus coreae has a much narrower host range than Aphelinus gossypii. Aphelinus coreae is very close to Aphelinus rhamni, but male Aphelinus coreae have shorter clubs and, as noted in the key, the two species differ in coloration of scape and mesotibia. Although difficult to distinguish, these species are reproductively isolated in laboratory crosses. Their DNA differs by 2130 fixed substitutions and 293 indels across 1.8 megabases of homologous DNA sequence. They also differ in host specificity: Aphelinus coreae parasitizes species of Aphis, e.g. Aphelinus nerii Boyer de Fonscolombe and Aphelinus rumicis L., not parasitized by Aphelinus rhamni in laboratory experiments.