Key to genus LONCHAEA and EAROMYIA . District of Columbia U.S.A.
Extracted from : Malloch and McAtee 1924. Keys to flies of the families Lonchaeidae, Pallopteridae, and Sapromyzidae of the eastern United States, with a list of the species of the District of Columbia region. Proceedings of the United States National Museum, 65(2525): 1-26, 2 pls..
1. Frons in both sexes with large irregular pits or depressions; a strong bristle near anterior margin of cheek … L. vibrissata Malloch.
- Frons impunctate or almost so, not pitted ………………………. 2
2. Several bristly hairs surrounding the stigmatal bristle ……………………. 3
- No hairs surrounding stigmatal bristle …………………………………………. 11
3. Fringes of calyptrae black or fuscous …………………………………….. 4
- Fringes of calyptrae white or yellow ………………………………………….. 9
4. Third antennal segment much less than twice as long as its greatest width; frontal lunule bare ; ovipositor abnormally wide ……………… Earomyia aterrima Malloch.
-Third antennal segment over twice as long as wide ; frontal lunule with some hairs ........................ 5
5. Eyes in both sexes distinctly hairy, in the male conspicuously so; second costal division very long; disk of scutellum hairy …………………………..……………. 6
Eyes bare or almost so ………………………………………………………………. 7
6. Pteropleura hairy in centre; cheeks with dense short erect fine hairs ……………………………………………………………………… L. pleurlseta Malloch.
- Pteropleura bare; cheeks with longer setulose hairs ………......................................................................……… L. ursina Malloch.
7. Tarsi entirely black …………………………………………….. L. atritarsis Malloch.
- Tarsi largely yellowish …………………………………………………………. 8
8. Orbit with several long fine hairs above the bristle; cheeks, frons, and mesonotum with rather dense erect black hairs ; wings whitish or yellowish, infuscated at bases ; scutellum with some long erect hairs on disk near apex as well as on the margins; pteropleura usually with one or two long hairs in centre………. L. hirta Malloch.
- Orbits bare or with a single hair above bristle; cheeks, frons, and mesonotum with more sparse black hairs ; scutellum generally bare on disk pteropleura bare ………………………………………………………………………….. L. affinis Malloch.
9. Third antennal segment but little longer than wide; scutellum with four strong bristles and no fine hairs ; face of male silvery ; ovipositor of female nearly as broad as frons, acutely pointed at apex, the preapical hairs very short ; auxiliary vein nearly fused with first at apex. ………………………………………….. L. arkansensis Malloch
- Third antennal segment about three times as long as wide; scutellum with some fine hairs on margins as well as the four long bristles ; face of male not silvery ; female ovipositor slender, very much narrower than frons ……………………………. 10
10. Glossy upper portion of orbits black; orbital bristle not proximad of anterior ocellus; cheek with dense short stiff hairs; third antennal segment not over three times as long as wide, almost entirely orange red. ………….......................… L. ruficornis Malloch.
- Glossy upper portion of orbits blue; orbital bristle distinctly proximad of anterior ocellus ; cheek with some short hairs and one or two longer bristles; third antennal segment over three times as long as its greatest width, upper half or more blackened ; hind femur with several long bristles on apical half of anteroventral surface ……………………………………………................................………………. L. winnemanae Malloch.
11. Ovipositor of female nearly as wide as frons; calyptrae and their fringes white; tarsi largely yellowish; scutellum without fine hairs……… L. arkansensis Malloch.
- Ovipositor slender, much narrower than frons ; scutellum usually with fine hairs in addition to the strong bristles ………………………………………….. 12
12. Face and parafacials when viewed from above conspicuously whitish pruinescent ; frons of female dark steel-blue, shining, sparsely and evenly haired, and with a transverse depression midway between anterior margin and anterior ocellus ; third antennal segment but little longer than wide ; a strong curved bristle near anterior margin of cheek ; tarsi slightly pale basally; calyptrae and their fringes brown; no fine hairs on scutellum ……. L. albiceps Malloch.
- Face but little whitish pruinescent when viewed from above; frons not steel-blue, and without a transverse depression; cheek either without a strong bristle or with several ……………………………………………………………………………………… 13
13. Legs entirely black ………………………………………………………….. 14
- At least the bases of tarsi yellowish ……………………………………………. 17
14. Fringes of calyptrae brown or fuscous ………………………………….. 15
- Fringes of calyptrae white; cheek without strong bristles ………………….. 16
15. Cheek with four outstanding bristles; no hairs between the scutellar bristles; frons slightly bluish or greenish; third antennal segment about 1.5 as long as wide …………………………………………………………………… L. quadrisetosa Malloch.
- Cheek without outstanding bristles; some fine hairs between the apical pair of scutellar bristles; frons black ……………… L. angustitarsis Malloch.
16. Some fine hairs between the apical pair of scutellar bristles. ....................L. vaginalis Fallen. (Probably not this species)
- No fine hairs between the apical pair of scutellar bristles …..................................... L. marylandica Malloch.
17. Frontal lunule bare; fringes of calyptrae brown; interfrontalia with two series of incurved hairs on centre; glossy portion of upper orbits microscopically strigose …………………………………………………………… Earomyia aberrans Malloch.
- Frontal lunule with setulose hairs at least on the sides except in nigrociliata; fringes of calyptrae whitish or yellowish except in nigrociliata and subpolita; glossy portion of upper orbits usually smooth (compare occidentalis and coloradensis) ……… 18
I8. No minute hairs between the apical pair of scutellar bristles; third antennal segment not or barely over twice as long as its greatest width ………………… 19
- Some minute hairs between the apical pair of scutellar bristles; third antennal segment more than twice as long as its greatest width …………………….. 20
19. Tarsi brown ; larger species, fully 4 mm. in length …........................................…. L. marylandica Malloch.
- Tarsi pale yellow; smaller species, less than 4 mm. in length. …….................. L. laticornis Meigen. (Probably not this species)
20. Fringes of calyptrae fuscous …………………………………………………… 21
- Fringes of calyptrae white or yellow; thorax and abdomen bluish ………………. 22
21. Frontal lunule bare; head and thorax black, abdomen slightly bluish,……………………………………………… Earomyia nigrociliata Malloch.
- Frontal lunule hairy; thorax and abdomen blackish blue ……… L. subpolita Malloch.
22. Width of male frons at anterior margin equal to at least half the entire length of frons ; preapical dorsal pair of hairs on ovipositor very long hairs at angle of calyptrae much longer than rest of fringe; upper orbits largely microscopically strigose ………………………………………………….. L. occidentalis Malloch.
- Width of male frons at anterior margin not nearly equal to half its entire length; preapical dorsal hairs on ovipositor very short; fringes of calyptrae of uniform length ……………………………………………………………………………………….. 23
23. Third antennal segment about twice as long as wide; upper frontal orbits granulose …………………………………………………… L. coloradensis Malloch.
- Third antennal segment at least three times as long as wide; upper frontal orbits largely or entirely polished …………………………………………………….. 24
24. Only the basal segment of each tarsus yellow ………… L. longlcornis Williston.
- Basal two or three segments of each tarsus yellow …………………………. 25
25. Larger species, over 4 mm. in length; hypopygium as in Figure 3, …………………………………………………………….. L. nudifemorata Malloch.
- Smaller species, less than 4 mm. in length; hypopygium of male as in gure 1 ………………………………………………………………. L. polita Say.