Last updated January 2024
1 Mid tibia completely yellow ……………………………..…………….…………….…….…. 2
1’ Mid tibia at least partly darkened …………………..………………….………………..……. 5
2(1) Fore coxa and mid femora yellow …………….…………………….………………….. sp. 8
2’ Fore coxa and mid femora dark ……………………………………………..……….…..….. 3
3(2) All funicle segments longer than wide …………………………………………………. sp. 6
3’ Some funicle segments quadrate or wider than long …………………………………………. 4
4(3) Scutellum not longitudinally reticulate centrally ……………………….……………… sp. 1
4’ Scutellum longitudinally reticulate ………………………………………….…………… sp. 4
5(1) All funicle segments longer than wide …….…………………………….…………..… 6
5’ Some funicle segments quadrate or wider than long …………………………….……..….… 7
6(5) Antenna uniformly dark brown; funicle length ~ 3x club …sp. 2
6′ Scape light apically, funicle and club light brown-yellow; funicle length ~ 1.5x club ……….. sp. 12
7(5) F2-F4 width greater than length …………………………………………………….……….. 8
7’ F2-4 quadrate or length greater than width …………………………………………….…….. 9
8(7) F1 quadrate, F6 lighter than other funicle segments, fore coxa dark …………………… sp. 5
8’ F1 wider than long, F6 concolorous with rest of funicle segments, fore coxa yellow ….. sp. 10
9(7) F1-4 length greater than width, F5-6 quadrate …………………………….….…………… 10
9’ Antenna otherwise ………………………………………………….………….….…….…… 11
10(9) Funicle brown, lighter apically; club obliquely truncate; mid tibia with dark markings exceeding midpoint ….. sp. 9
10’ Funicle uniformly dark yellow; club apically rounded; mid tibia with dark ring restricted to basal third ……..…… sp. 11
11(9) Scutellum flattened, sculpture very shallow ……………………………..…………… sp. 3
11’ Scutellum convex, deeply sculptured ………………………………….………..…………. 12
12(11) Speculum reduced ……………smithi
12’ Speculum distinct …………………………13
13(12) F1 quadrate, equal to F2 ………………………………..………..…………… 14
13’ F1 slightly longer than wide, longer than F2 ……… 15
14(13) F1 & F2 narrower than remaining funicle segments; ratio of scutellum width (at axillae) to length 1.5:1.0 ………….aphidivorus
14′ All funicle segments of equal width; scutellar width about equal to length …………………………………….. sp. 14
15(13) Club length about 0.75x funicle length; ovipositor sheaths not distinctly protruding ……. sp. 7
15′ Club length about 0.6x funicle length; ovipositor sheaths distinctly protruding …………..sp. 13
Sp. 1 Alameda, Contra Costa, Los Angeles, Plumas, San Benito (EMEC, RLZC)
Sp. 2 Nevada, (SBNHM), Tuolumne (UCFC)
Sp. 3 Alameda, Marin (RLZC), Placer (UCRC), El Dorado (UCDC)
Sp. 4 Orange, Solano (UCDC)
Sp. 5 Marin (RLZC)
Sp. 6 Plumas, Riverside (RLZC), San Francisco (CAS)
Sp. 7 Los Angeles, Modoc, San Bernardino, Stanislaus (CAS, RLZC, UCFC. UCRC)
Sp. 8 Alpine (USUC), El Dorado (UCDC), Mono, Plumas (RLZC), Tuolumne (UCFC),
Sp. 9 Kern (RLZC)
Sp. 10 Sonoma (CSCA)
Sp. 11 Riverside (UCR)
Sp. 12 Modoc (RLZC)
Sp. 13 El Dorado (RLZC)
Sp. 14 Inyo (UCRC)
Described Nearctic species and distribution
aphidivorus (Mayr, 1876): USA (CA, CN, FL, ID, IN, KY, LA, ME, NJ, NM, NY, OH, OK, PE, SC, TX, VA)
lachni(Ashmead, 1885): USA (FL)
marilandicus (Girault, 1917): USA (MD)
quadrimaculatae (Ashmead, 1881): USA (FL, LA, MS, NC, SC)
smithi Kamal, 1926: USA (CA)
Remarks
Sanderson (1901) reported a “Syrphophophagus flavipes Ashm.” from Delaware, but this is an unavailable name. In 2018 I was unable to locate the type of S. lachni or S. marilandicus at the USNM, but a slide specimen of the latter species was present in the regular collection with one wing, one leg and the head with antenna – it has a white scape, F1 longer than wide, F2 and F3 slightly longer than wide, F4-F6 quadrate, and doesn’t match any of the undetermined species. The holotype of S. quadrimaculate is missing the head and one forewing. It may key to sp. 8, but the fore coxae is not visible, and the scutellum is relatively convex and the poserior edge of the hind tibia is dark, while sp. 8 has a flatter scutellum and the hind tibia is all yellow.
References
Ashmead, W.H. 1881. On two new chalcid flies from Florida, parasitic upon the larvae of syrphus flies. The Canadian Entomologist 13: 170-172.
Ashmead, W. H. 1885. Studies on the North American Chalcididae, with descriptions of new species from Florida. Transactions of the American Entomological Society 12: x-xix.
Girault, A.A. 1917. New chalcid flies from Maryland, II (Hym). Entomological News 28: 255-258.
Kamal, M. 1926. Four new species of parasites from aphidophagous Syrphidae (Hymenoptera). Canadian Entomologist 58: 283-286.
Mayr, G. 1876. Die europaïschen Encyrtiden. Verhandlungen der Zoologisch-Botanischen Gesellschaft in Wien 25: 675-778.
Sanderson, E.D. 1901. Report of the entomologist. Annual report of the Delaware College Agricultural Experiment Station 12: 259 pp.