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Key to the genera of Tachinidae in the eastern US
This key is reduced from the key by D. M. Wood that appeared in Volume one of the Nearctic Diptera catalog that is currently out of print. (Thanks again to Judy Semroc.) This key has been updated to the genera in the new catalog from James O'Hara and D. M. Wood published in Jan. 2004. As with most of my modified keys I have removed the genera that are strictly western. And species that occur only in south and west Texas. All other genera that occur anywhere in the east are included.
This is a massive group. And I don't recommend you start here if you are interested in flies, or insects in general for that matter. This is a difficult and detailed key and one of the few that I have on this site that I would not recommend tackling without a good magnifying scope. A hand lens will not suffice. This is not a hand lens kind of key. It was while I was preparing this key that I finally broke down and bought a scope. I don't plan to use this monster key without significant magnification. This key does not use many genitalic features but it is just ripped with divisions involving placement and numbers of bristles and hairs -- one of the distinct features of the Tachinid flies. My list of species for the east is here.
I have split this key into serial multiple site pages to make for easier download with the extensive scans included. The scans are all from the Wood section of the Nearctic catalog. With the page splits, clicking on the numbers to the right of the divisions will take you directly to the pages later in the key if the split jumps that far. Otherwise, each page has a 1,2,3,4 button at the bottom for the four pages. There are several genera in the new catalog that I cannot place in this key as I don't yet know where they should appear. Several are known to be split from genera in the Wood key and these are noted in parentheses as "included." The others specifically are Argyrophylax, a new genus and species found in Florida that spilled up from the West Indies, and Otomasicera, known in the east from MA. Both are in the Goniini tribe. The rest are included in the confusing and much revised Polideini tribe: Chromatocera, Exoristoides, Homalactia, and Micronychia. And any species keyed to the related genera in the Polideini (list for that section is here) should be examined carefully until I have more information on these genera. (#/#) after the genera is eastern species/total species in genus.
Separations in red are major divisions in the genera.
A selection of Tachinid facial portraits: http://cedarcreek.umn.edu/insects/album/029105ap.html
And this fly anatomy site is worth a long detour: |
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1. Prosternum setose, sometimes sparsely so
2
1. Prosternum without setae
2. Scutum with five or more postsutural supra-alar bristles, two anterior to the largest bristle, first bristle arising close to transverse suture; second bristle smallest and displaced medially
3
2. Scutum with three or four postsutural supra-alar bristles, only one anterior to the largest bristle, first bristle arising more or less equidistant between transverse suture and second bristle
3. Anepimeron with an exceptionally long bristle extending posteriorly beyond middle of lower calypter. Anterior and posterior lappets of posterior thoracic spiracle about equal in size, each with a fringe of plumose hairs enclosing a narrow V-shaped opening at or near middle of spiracle
4
3. Anepimeron with shorter bristles not extending to middle of lower calypter or with none. Anterior and posterior lappets of posterior spiracle unequal; the posterior one larger, forming a crescent-shaped opening with anterior lappet
4. Dorsal surface of lower calypter, except for a narrow band along posterior margin, covered with long erect hairs (see first image at 3)
Hystricia Macquart (1/2) abrupta Wiedemann
4. Dorsal surface of lower calypter without long erect hairs. Body bright metallic green or blue
Chrysotachina B. & B. (4/5)
5. Thorax, abdomen, and most of head metallic green or blue. First postsutural intra-alar bristle about as close to transverse suture as first dorsocentral bristle; outer basal bristle of postpronotum not accompanied by a smaller posteromedially placed bristle Gymnocheta R-D., in part (2/4)
5. Thorax, abdomen, and head without metallic green integument. First postsutural intra-alar bristle almost as close to transverse suture as first postsutural intra-alar bristle and much closer to suture than first postsutural dorsocentral bristle; outer basal bristle of postpronotum with a smaller bristle posteromedial to it. Abdomen brown, gray or bluish tesselated
Xanthophyto Townsend (2/2)
6. First postsutural supra-alar bristle (lower labeled bristle below) at least as long and stout as first postsutural dorsocentral bristle (upper labeled bristle below)
7
6. First postsutural supra-alar bristle shorter and finer than first postsutural dorsocentral bristle
7. Ocellar bristles reclinate or lateroclinate
8
7. Ocellar bristles proclinate or absent
8. Parafacial bare (see second image just above)
Distichona Wulp, in part (3/3)
8. Parafacial setose (see first image just above)
9
9. Eye covered with conspicuous dense hairs, each hair longer than combined diameter of four or more eye facets. Lower part of parafacial with patch of fine hairs
D. autumnalis
Distichona Wulp, in part (3/3)
9. Eyes apparently bare. Parafacial with coarse hairs or bristles or both over most of its length 10
10. Parafacial with an even row of four or more bristles adjacent to ptilinal fissure, isolated from smaller remaining parafacial setae. Second aristomere usually 10 or more times as long as wide, and usually more than half as long as third aristomere. Male with proclinate orbital bristles
10. Parafacial with scattered setae; if those nearest ptilinal fissure appear larger, then they are distant from fissure by at least half their length and do not form an even row. Second aristomere usually less than 5 times as long as wide, and usually less than half as long as third aristomere. Head and body gray or silvery pruinescent
Spallanzania R-D. (4/6)
11. Eye covered with conspicuous dense hairs
12
11. Eye apparently bare (hairs usually present, but so sparse and short as to be easily overlooked, each hair no longer than combined diameter of two facets)
12. Postpronotum with middle basal bristle displaced anterolaterally forming a nearly right-angled triangle with outer and inner basal bristles (center illustration below); middle basal bristle also arising lateral to a line between outer basal and outer anterior bristles
13
12. Postpronotum with middle basal bristle more or less in line with outer and inner basal bristles (right image above), or with inner basal bristle absent (left image above); if middle basal bristle forming an apparent angle with outer and inner basal bristle, this angle at least 160 degrees; middle basal bristle usually medial to a line between outer basal and outer anterior bristles (latter not always present)
13. Katepimeron haired, at least on its anterior two-thirds (left pointer below)
14
13. Katepimeron bare, or with at most three or four hairs on anterior fourth
14. Parafacial with hairs on upper half or more
15
14. Parafacial bare on lower two-thirds or more
16
15. Hairs on abdominal tergites 3 and 4 recumbent. Katepisternum rarely with more than two bristles
Winthemia R-D., in part (includes Smidtia) (22+1/29+1)
15. Hairs on abdominal tergites 3 and 4 erect, at right angles to surface of tergite. Katepisternum with three bristles
Diotrephes Reinhard (1/1) atriventris Walker
16. Facial ridge with bristles on at least lower third or more (see second image on 14)
Hemisturmia Townsend (2/2)
16. Facial ridge bare on all but lowest fifth
17
17. Abdominal tergites 3 and 4 with median discal bristles. Scutum with a median dark longitudinal stripe and a paired lateral stripe
Nemorilla Rondani (2/2)
17. Abdominal tergites 3 and 4 without median discal bristles. Scutum with a pale median stripe and two pairs of longitudinal stripes
Orasturmia Reinhard (1/1) vallicola Reinhard
18. Facial ridge with row of long erect bristles on lowest two-thirds or more
Patelloa Townsend (8/10)
18. Facial ridge with at most a row of hair-like decumbent setae on lower half or less
19
19. Hind coxa with one or more setae on posteroapical margin
Hyphantrophaga Townsend, in part (6/9)
19. Hind coxa bare on posteroapical margin (hairs arising on first abdominal segment may, in profile, appear to arise on coxa) 20
20. Gena exceptionally narrow; distance between eye and lower cranial margin less than one-tenth total height of head
Houghia Coquillett (4/5)
20. Gena broader; distance between eye and lower cranial margin more than one-ninth height of head
21
21. Palpus black 22
21. Palpus brown, yellow or orange
22. Facial ridge with slender decumbent setae on lower third to half, the length of this row more than half the length of palpus
Myxexoristops Townsend, in part (2/2)
22. Facial ridge with only a few small setae on lower fourth or less; length of this row less than half the length of palpus 23
23. Facial ridge thickened, slate gray, contrasting with adjacent brassy-pruinescent parafacial; parafacial slightly concave just below lowest frontal bristle; pruinescence at this point appearing as a shiny spot when illuminated from below, or as a dark spot when illuminated from above. Male lacking an outer vertical bristle
E. futilis
Euexorista Townsend (1/1) rebaptizata Gosseries
23. Facial ridge narrow, not contrasting with adjacent parafacial in color; parafacial without concave area just below lowest frontal. Male with an outer vertical bristle
Prooppia Townsend (2/3)
24. Facial ridge with slender decumbent setae on lower third to half, the length of this row more than half the length of palpus (see image at 22)
Myxexoristops Townsend, in part (2/2)
24. Facial ridge with only a few small setae on lower fourth or less; length of this row less than half the length of palpus 25
25. Mid tibia with one anterodorsal bristle, or if with two, then the lager bristle is proximal and the smaller one is distal. Abdominal tergites 3 and 4 with at most one pair of discal bristles. Abdomen globose, especially in female, as deep as wide, enclosing terminalia within a slit-like opening. Facial ridge straight or slightly convex in profile, except just above vibrissa. Cerci of male without interlocking teeth at apices
Hyphantrophaga Townsend, in part, (6/9) blandita Coquillett in this section
25. Mid tibia with two or more anterodorsal bristle, with the largest the most distal. Abdominal tergites 3 and 4 usually with more than one pair of discal bristles; abdominal tergite 5 enclosing a rounded or triangular opening, not concealing terminalia. Facial ridge concave in profile. Cerci of male with medially directed interlocking teeth at apices
Phebellia R-D., in part (7/8)
26. Parafacial with setae on upper half or more
27
26. Parafacial bare, or with at most a few hairs below lowest frontal bristle
27. Parafacial with vertical rows of erect setae or different sizes; these larger and bristle-like anteromedially, fine and hair-like posterolaterally (see left face at 26 above)
Gaediopsis B. & B. (2/9)
27. Parafacial setae of uniform size, all hair-like and decumbent (see right face at 26 above) 28
28. Parafacial very broad, setose on upper half (see right face at 26); vibrissa arising above level of lower facial margin; ocellar bristles well-developed. Katepimeron bare
Mystacella Wulp (1/3) chrysoprocta Wiedemann
28. Parafacial narrow, setose along its entire length; vibrissa level with lower faical margin; ocellar setae hair-like. Katepimeron entirely setose
W. rufopicta
Winthemia R-D., in part, (22/29) antennalis Coquillett in the east in this section
29. Hind coxa with one or more setae on posteroapical margin
Carcelia R-D. (13/13)
29. Hind coxa bare on posteroapical margin
30
30. Apical scutellar bristles hair-like, parallel or divergent, or absent
Cyzenis R-D. (3/5)
30. Apical scutellar bristles crossed
31
31. Facial ridge setose on at least lower third
32
31. Facial ridge bare except for a few recumbent seta on lowest third or less
32. Distance between eye and subcranial margin less than one-tenth height of head. Frons with two or more large reclinate orbital bristles arising distinctly lateral to frontal row, the anteriormost arising near midlength of frons; ocellar setae minute or absent
Pseudochaeta Coquillett (7/11 in 3 subgenera)
32. Distance between eye and subcranial margin more than one-sixth height of head. Reclinate upper orbital bristles confined to posterior third of frons, usually arising behind uppermost frontal; ocellar setae well-developed 33
33. Katepisternum with four or more bristles
34
33. Katepisternum with three bristles
34. Katepisternum with posteroventral bristle arising nearly in line with anterior and posterior bristles and nearly equidistant between the two; only the anteroventral bristle displaced ventrally. Apical scutellar bristles directed posteriorly, almost horizontally
Nilea R-D., in part (8/12)
34. Katepisternum with both posteroventral and anteroventral bristles displaced ventrally; the posteroventral bristle much closer to the posterior than to the anterior bristle (see 33 first image). Apical scutellar bristles erect, nearly at right angles to scutellum
Lespesia R-D., in part (26/32)
35. Katepisternal bristles arising quite close together; distance between anterior and posterior bristles less than three times distance between anterior and anteroventral bristles
36
35. Katepisternal bristles more dispersed; distance between anterior and posterior bristles more than three times distance between anterior and anteroventral bristles
36. Facial ridge with row of stout erect bristles. Third aristomere thickened on basal three-quarters or more
Madremyia Townsend (1/2) saundersii Williston
36. Facial ridge with finer more decumbent setae. Third aristomere thickened on basal two-thirds or less
P. pecosensis
Phryxe R-D. (2/2)
37. Bend of M nearly at right angle without a stub, or continuation of M. Apical scutellar bristles directed posteriorly, almost horizontally. Frons with a single row of frontal bristles
Nilea R-D., in part (8/12)
37. Bend of M either with a short stub or distinctly obtuse. Apical scutellar bristles inclined at 45 degrees or more to horizontal, usually curving forward. Frons with extra row of bristles outside frontal row
A. texana
Acantholespesia Wood (2/3)
38. Katepisternum with four bristles arranged in a trapezoidal pattern
39
38. Katepisternum with two or three bristles (a fourth may rarely occur either between anterior and posterior bristles or ventral to anteroventral one, not forming a trapezoid) 40
39. Parafacial with a few hair-like setae below lowest frontal bristle. Frons with one or more rows of bristles (o fr s) lateral to frontal row. All abdominal tergites with transverse bands of silvery pruinescence
E. longicornis
Eunemorilla Townsend (1/5) comosa Reinhard
39. Parafacial bare below lowest frontal bristle (see second pair of images at 41 below). Frons with only scattered hairs outside frontal bristles. Abdominal tergite 5 of female and tergites 4 and 5 of male shining black except narrow basal band of silvery pruinescence on tergite 4 Aplomya R-D. (1/1) theclarum Scudder
40. Palpus black or dark brown
41
40. Palpus pale brown or yellowish
41. Parafacial with several hairs below lowest frontal bristle
Eumea R-D. (1/1) caesar Aldrich
41. Parafacial without hairs below lowest frontal
Platymya R-D. (2/2)
42. Hind tibia with comb-like row of anterodorsal setae of rather uniform length, except for one longer bristle at midlength. Abdominal tergites 2 and 3 each lacking median discal bristles
Sisyropa B. & B. (2/2)
42. Anterodorsal setae of hind tibia uneven in length, alternating long and short. Abdominal tergites 2 and 3 each with scattered median discal bristles 43
43. Hind coxa with one or more setae on posteroapical margin
Hubneria R-D. (1/1) estigmenensis Sellers
43. Hind coxa bare on posteroapical margin 44
44. Apex of abdomen of male with a pair of circular patches of appressed hair arising from shiny black cuticle ventrally (female unknown)
Aplomyopsis Townsend (1/1) polita Coquillett
44. Apex of abdomen lacking such patches of appressed hair
Phebellia R-D., in part (7/8)
45. Gena reduced to a narrow strip about one-twelfth height of head
46
45. Gena higher at least one-tenth height of head
46. Frons with two or more stout reclinate orbital bristles arising distinctly outside frontal row; facial ridge with stout bristles on lower half or more; ocellar setae minute or absent
Pseudochaeta Coquillett, in part (7/11 in 3 subgenera)
46. Frons with reclinate orbital bristles more or less continuous with frontal row; facial ridge with fine hairs, or with a few bristles on lowest fourth, or bare; ocellar setae well-developed
47
47. Palpus inflated apically, with the swollen part bare. Gena almost obliterated by lower margin of eye, scarcely visible in profile
Hypertrophomma Townsend (1/1) opacum Townsend
47. Palpus setose, not inflated apically. Gena although narrow, with both genal dilation and genal groove evident
Houghia Coquillett, in part (4/5)
48. M ending in R4+5 some distance from wing margin
49
48. M ending in wing margin separately from R4+5
49. Proboscis elongate and very slender, longer than height of head. Posteriormost orbital bristle lateroclinate. Postpronotum with only two bristles
Chaetoglossa Townsend (2/2)
49. Proboscis not elongate, shorter than height of head. Posteriormost orbital bristle reclinate. Facial ridge bristled on most of its length. Parafacial bare
Erynnia R-D. (1/4) tortricis Coquillett
50. Anterodorsal bristles on hind tibia forming an even closely spaced row; each bristle separated from adjacent bristles by no more than three times its width (in female one bristle near middle of row usually slightly longer than the rest)
51
50. Anterodorsal bristles on hind tibia irregular in length and spacing; each separated from adjacent setae by over three times its width (both sexes always with at least one much longer bristle near middle of row)
51. Abdomen black or dull dark brown without tessellated pattern of pruinescence. Anterodorsal setae of hind tibia nearly touching each other in both sexes (see image at 50). Tergite 4 of male without patch of short dense hairs
Leschenaultia R-D. (5/12)
51. Abdomen gray or brown, with tessellated pattern of pruinescence. Anterodorsal bristles of hind tibia usually more widely spaced
52
52. Katepisterum with four bristles. Subvibrissal ridge with row of usually fewer than four bristles; this row less than half as long as length of row of setae on facial ridge. Abdomen of male without patches of short dense hair
Lespesia R-D., in part (26/32)
52. Katepisterum with three bristles, the posteroventral one absent. Subvibrissal ridge with evenly spaced row of more than four bristles; this row as long as row of setae on facial ridge. Tergite 4 of male with patch of short dense hairs
Blepharipa Rondani (2/2)
53. Parafacial with setae over upper half or more
54
53. Parafacial bare, or at most with a few hairs below lowest frontal bristle
54. Facial ridge with row of stout erect curved bristles on more than lower half. Bristles of facial ridge as long as width of parafacial, and more widely spaced
Chaetogaedia B. & B. (3/7)
54. Facial ridge with bristles confined to region of vibrissa; ocellar setae nearly as long as either reclinate bristle. Pedicel less than half as long as first flagellomere.
Buquetia R-D. (1/1) obscura Coquillett
55. Facial ridge with erect bristles on lower half or more
56
55. Facial ridge bare, or with small recumbent setae on lower third
56. Ocellar setae absent. Katepisternum with four or more bristles arranged in a row. Abdominal tergite 5 and often 4 with gold or orange pruinescence
Belvosia R-D. (14/15)
56. Ocellar setae well-developed, bristle-like
57
57. Anterior margin of postgena without a genal dilation. Arista pubescent
Prospherysa Wulp (1/2) pulverea Coquillett
57. Anterior margin of postgena with well-developed genal dilation. Arista apparently bare
58
58. Katepisternum with four bristles. Upper orbital bristles reclinate; if more than one present, then bristles arranged in a longitudinal row
Lespesia R-D., in part (26/32)
58. Katepisternum with three bristles. Abdomen black, with transverse gray pruinescent bands.
Frontiniella Townsend (5/10)
59. Postpronotum with middle basal bristle displaced anteriorly, forming a triangle with outer and inner basal bristles
60
59. Postpronotum with middle basal bristle more or less in line with outer and inner basal bristles, or inner basal bristle absent
60. Lower facial margin sloping evenly forward from lower part of face, thus visible in lateral view below and in front in vibrissal angle. Postpronotum with five large bristles arranged in a V
Masiphya B. & B. (3/5)
60. Lower facial margin, if visible in profile, bent forward abruptly at level of vibrissal angle. Postpronotum with three large bristles, sometimes with one or two additional smaller ones anteriorly
Allophorocera Hendel (6/14)
61. Bifurcation or R2+3 and R4+5 with a single rather long seta on dorsal surface
62
61. Bifurcation or R2+3 and R4+5 with two or more small seta on dorsal surface
62. Katepisternum with three bristles. Fronto-orbital plate with a single row of frontal bristles; anterior reclinate orbital bristle larger than posterior one, with the two well separated from each other
Ametadoria Townsend (1/1) harrisinae Coquillett
62. Katepisternum with four bristles. Fronto-orbital plate with extra medioclinate bristles outside frontal row, usually forming a second row; two or three reclinate orbital bristles usually present, but if only two, then anterior one usually smaller than the posterior one
63
63. Ocellar bristles long, divergent
Lydella R-D. (3/3)
63. Ocellar bristles short, curving toward each other apically (oc s below), or absent
Drino R-D. (6/6)
64. Notopleuron with one or more smaller bristles in addition to the usual two large ones (lower left npl s below)
Atacta Schiner (2/2)
64. Notopleuron with two bristles (lower left bristles below)
65
65. Lower facial margin protruding in front of vibrissal angle when viewed laterally
Siphosturmia Coquillett (3/8)
65. Lower facial margin not visible in lateral view
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