Key to the Alabama Species of Chaetocnema
Chaetocnema denticulata (Illiger)
Chaetocnema minuta Melsheimer
Chaetocnema alutacea Crotch
Chaetocnema pulicaria Melsheimer
Chaetocnema crenulata Crotch
Chaetocnema confinis Crotch*
Chaetocnema blatchleyi Csiki

1. Sides of pronotum regularly arcuate from base to apex, anterior angles not obliquely     truncate…..      2
    Sides of pronotum obliquely truncate at anterior angles and with lateral angulation in front of      middle….. C. confinis
2. Median area of frons punctate, sometimes indistinctly….. 3
    Median area of frons impunctate; large, often setigerous punctures may be present in or near      supra-orbital groove, or vertex of occiput may be punctate….. 4
3. Punctures of frons distinct; color bronze….. C. denticulata
    Punctures of frons indistinct; color bronze-black….. C. minuta
4. Basal marginal line of pronotum not defined by punctures….. 5
    Basal marginal line of pronotum with punctures; sometimes punctures continuing to     middle….. 6
5. Larger (2.7-3.0 mm.); antennae uniformly dark brown….. C. blatchleyi
    Smaller (1.9-2.3 mm.); antennal segments 2 through 6 light brown….. C. alutacea
6. Pronotum finely and sparsely, but very distinctly, punctate….. C. pulicaria
    Pronotum with coarse, moderately deep punctures irregularly placed….. C. crenulata

Chaetocnema denticulata (Illiger) (Fig. 39)

Haltica denticulata Illiger, 1807, Mag. Insektenk. 6: 163.
Chaetocnema semichalcea Melsheimer, 1847, Proc. Acad. Nat. Sci. Philadelphia 3: 167.
Chaetocnema americana Motschulsky, 1860, in Schenck, Reisen Amurl. II., p. 235.
Chaetocnema texana Crotch, 1873, Proc. Acad. Nat. Sci. Philadelphia 25: 74.
     Oval, bronzed. Head alutaceous; frons and vertex distinctly, moderately closely punctate; clypeus with larger, coarser, closer punctures; antennal basal segments red-brown. Pronotum alutaceous, strongly punctate. Elytra alutaceous, punctate-striate to apex. Legs brown, except femora of hind legs bronze. Length 2.0-3.3 mm. Width 1.1-1.8 mm.
     Alabama records: 61 specimens from Baldwin^1,2, DeKalb¹, Houston¹, Jefferson¹, Lee¹, Limestone¹, Marshall¹, Mobile², and Randolph¹ counties.
     Seasonal distribution: March 20-September 25.
     Remarks: This species is commonly known as the toothed flea beetle.

Chaetocnema minuta Melsheimer

Chaetocnema minuta Melsheimer, 1847, Proc. Acad. Nat. Sci. Philadelphia 3: 167.
     Oval. Shining bronze-black. Frons alutaceous, sparsely, minutely punctate. Antennae with basal 4 joints red-yellow, segments 5-11 dark brown. Pronotum convex, lateral margins strongly arcuate, surface alutaceous, sparsely finely punctate, basal margin with larger punctures. Elytra wider than thorax at base; apical declivity beginning at about 1/2 of elytral length; striae faintly impressed, punctures moderate. Femora dark brown, tibiae and tarsi lighter brown. Length 1.8-1.9 mm. Width 0.9-1.1 mm.
     Alabama records: 7 specimens from Mobile² County.
     Seasonal distribution: April 12-July 4.
     Remarks: In Loding's collection and checklist this species was listed as C. parcepunctata Crotch. We prefer to refer these to C. minuta since the frons of these beetles has minute punctures, a feature supposedly lacking in C. parcepunctata. Horn (63) indicated this possibilty. Further, several specimens in the USNM bore determination labels with both of these names. Seasonally, Alabama C. minuta have been collected from April 12 to July 4.

Chaetocnema alutacea Crotch

Chaetocnema alutacea Crotch, 1873, Proc. Acad. Nat. Sci. Philadelphia 25: 74.
     Oval. Black with slight hint of olive-green or blue. Head impunctate except for very few setigerous punctules in frontogenal suture, frons and vertex more finely alutaceous than clypeus, lateral margins of clypeus with row of large punctures; antennae with basal and 5 apical segments dark brown, segments 2-6 lighter brown. Pronotum strongly alutaceous, coarsely punctate. Elytra very distinctly alutaceous but less so than pronotum, striate-punctate, punctures large. Legs entirely piceous. Length 1.9-2.3 mm. Width 1.1-1.2 mm.
     Alabama records: 9 specimens from Mobile^2,3 County.
     Seasonal distribution: May 9-July.
     Remarks: Six of the 9 specimens examined were collected by H. Soltau and are deposited in the USNM; the other 3 are Loding's. Alabama examples of this species are smaller than specimens in the USNM from either Maryland or Florida.

Chaetocnema pulicaria Melsheimer

Chaetocnema pulicaria Melsheimer, 1847, Proc. Acad. Nat. Sci. Philadelphia 3: 167.
Chaetocnema aeneola LeConte, 1879, Bull. U. S. Geol. Surv. 5: 518.
     Oval, black-bronze. Head alutaceous; indistinctly punctate in small depression on lateral portion of frons even with top of eyes, usually one puncture deeper, setigerous. Pronotum alutaceous, punctate, distinctly narrower than elytra at base. Elytra striate-punctate to apex, shining. Femora piceous, tibiae and tarsi lighter brown. Length 1.4-1.8 mm. Width 0.9-1.1 mm.
     Alabama records: 84 specimens from Baldwin¹, Cleburne¹, Coosa¹, Jackson¹, Jefferson¹, Lee¹, Limestone¹, Macon¹, Madison¹, Marion¹, Marshall¹, Talladega¹, and Tallapoosa¹ counties.
     Seasonal distribution: March 3-December 2.
     Remarks: The senior author has collected this little flea beetle by sweeping Trifolium incarnatum, Medicago sativa, Vicia sp., and Convolvulus sp. from March 3 to December 2. Although Loding (75) listed it from "over state", no specimens were seen in his collection.

Chaetocnema crenulata Crotch

Chaetocnema crenulata Crotch, 1873, Proc. Acad. Nat. Sci. Philadelphia 25: 74.
     Broadly oval, robust. Shining black, faintly bronzed. Head alutaceous, frons impunctate but vertex sometimes with scattered large punctures. Antennae, tibiae, and tarsi red-brown. Pronotum not more narrow than elytra, alutaceous, coarsely, irregularly punctate, basal margin line distinct. Elytra smooth, very shiny, punctate-striate, intervals rather convex; humeri smooth, not prominent. Venter black; femora bronzed. Length 1.9-2.0 mm. Width 1.2-1.3 mm.
     Alabama records: 3 specimens from Lee¹ County.
     Seasonal distribution: May 13-September 13.

Chaetocnema confinis Crotch*

Chaetocnema confinis Crotch, 1873, Proc. Acad. Nat. Sci. Philadelphia 25: 75.
Chaetocnema flavicornis LeConte, 1878, Proc. Amer. Philos. Soc. 17: 418.
     Broadly ovate, black with bronzed lustre. Head alutaceous, impunctate or with few punctures in small depression on lateral portions of frons even with top of eyes; antennae entirely red-brown. Prothorax with lateral margins angulate behind front angles. Elytra regularly striate-punctate to apex. Length 1.5-1.8 mm. Width 0.8-1.1 mm.
     Alabama records: 50 specimens from Baldwin¹, Clay¹, Cleburne¹, DeKalb¹, Elmore¹, Etowah², Franklin¹, Jefferson¹, Lee¹, Macon¹, Marion¹, Mobile², and Tallapoosa¹ counties.
     Seasonal distribution: April 13-October 29.
     Remarks: This species is commonly known as the sweetpotato flea beetle. It feeds on sweetpotatos and wild morning glories (Convolvulus sp.).

Chaetocnema blatchleyi Csiki

Chaetocnema robusta Blatchley, 1923, Canadian Entomol. Soc. 55: 33 (not Baly).
Chaetocnema blatchleyi Csiki, 1940, Coleopt. Cat. pars. 169, Halticinae II., p. 401.
     "Oblong oval, convex, very robust . . . Black, subopaque with a faint, brassy tinge; antennae piceous-brown throughout; femora black, tibiae and tarsi dark reddish brown . . . Length 2.7-3 mm." (30).
     Alabama records: Mobile³ County.
     Remarks: Blatchley (30) reported that, according to H. C. Fall, specimens of this species were deposited in the "Cambridge Museum" from Mobile. Blatchley (30) described this species as C. robusta. Csiki (47), upon discovering that C. robusta Blatchley was a junior homonym of Baly's C. robusta, proposed the new name blatchleyi. No specimens from Alabama were seen, either in Loding's collection or that of the USNM; however, a paratype, of C. robusta Blatchley, was studied at the latter institution.