IDENTIFICATION PAGE # 11:  Lasioglossum (Dialictus)

Is it possible to identify this Lasioglossum (Dialictus) from the Valley?  

I've compiled a list of Lasioglossum (Dialictus) bees documented in the Valley.  (This is below the images).

 I was wondering if this might be Lasioglossum (Dialictus) connexum?

This Lasioglossum (Dialictus) is a  smallish dark bronze-green bee with reddish jaws that are black at the base.  It was feeding on mallows.

Lasioglossum (Dialictus)

Size:  a little less than 5 mm (1/5 in. (female)

Associated plant at NBC:  

Spiked malvastrum

(Malvatrum americanum)

Plant family:   Malvaceae

When seen:  November 2018 

This female bee is a dark greenish bronze, with a dark abdomen. Its tegulae and tarsi are reddish-brown. The base of each tibia on the front and middle legs is also reddish. There are fine, pale hairs on the bee's body and legs.

The jaws are mostly dark red, and black at the base. Its antennae are mostly black, and brownish on the undersides of the top six flagellar segments.

The bee's abdomen is anon-metallic black, and covered with fine white hairs.

This is a small bee -- a little less than 2/5 the width of a dime - a little less than 1/5" long (.5 cm).

Female bee

Female bee


Data on Lasioglossum is of course skewed toward eastern species and

The following sources were used to compile a list of Texas and LRGV Lasiglossum (Dialictus) species:

(1) Cresson, E.T. “Hymenoptera Texana,” Transactions of the American Entomological Society, vol 4 (1872/1873) pp. 153-292.

(2) Cockerell, Wilmatte P. “Collecting Bees in Southern Texas.” Journal of the New York Entomological Society, vol. 25.3 (1917).

(3) Gibs, Jason. “Revision of the metallic species of Lasioglossum (Dialictus) in Canada (Hymenoptera, Halictidae, Halictini),” Zootaxa, vol. 2591.1, 2010, pp. 1-382.

(4) Gibs, Jason. “Revision of the metallic Lasioglossum (Dialictus) of eastern North America (Hymenoptera: Halictidae: Halictini),” Zootaxa, vol. 3073 (2011): pp. 1-216. 

5 ) Mitchell, T.B. (1960) Bees of the eastern United States, Volume One. I.  North Carolina Agricultural Experiment Station (1960):  pp. 331-521. 6) .   (This is useful, although it of course omits many wsetern and border species.)

6) Databases:   I-naturalist (I-nat) – Lasioglosum (Dialictus) entries for Texas; Bug Guide (BG)– Lasioglosum (Dialictus) entries for Texas; Discover Life Database (DLD)– Species entries and maps for Lasioglossum (Diaictus).



LRGV SPECIES  - There are 5 Lasioglossum (Dialictus) species reported specifically for the Valley:  Lasioglossum connexum, L. coactum, L. disparile, L. rodognathus and L.  semicaeruleum.

1. Lasioglossum (Dialictus) connexum:  Cresson (1872) describes this species in Hymenoptera Texana. In 1917, WIlmatte Cockerell reported Lasioglossum connexum (under the synonym Halictus (Chloralictus) politissimus Cockerell) in San Benito of Cameron County (in Collecting Bees in Southern Texas (p. 189).


Description:  W. Cockerell's 1917 description reads: “Halictus (Chloralictus) politissimus new species.  Length about 5 mm., anterior wing 4 mm.; rather robust, the head broad and round, but not unusually large; head and thorax shining dark green, abdomen and legs black; mandibles obscurely reddish apically; head and thorax with short, sparse, dull white hair; face and front shining, the front finely and not very densely punctured, the punctures much smaller at the sides than in the middle; antenna dark, the flagellum obscurely brown beneath toward end; mesothorax convex, highly polished, with scattered, weak punctures; scutellum polished; metapleura minutely cross-striate; area of metathorax with irregular longitudinal plicae on the basal half; tegulae dark reddish; wings hyaline, strongly iridescent, stigma and nervures very pale testaceous; hind spur of hind tibia with three or four large blunt teeth; abdomen rather thinly pruinose-pubescent; bases of segments with beautifully plumose hairs-; no conspicuous punctures on abdomen. Tegulae not punctured. San Benito, Texas, at flowers of Argemone (W. P. Cockerell). Not unlike H. crassiceps Ellis, but smaller, with much smaller head. 1 By T. D. A. Cockerell.”

The Discover Life Database notes that Lasioglossum connexum was found in Brownsville, Cameron County in 2009 (; and in Roma-Los Saenz in Starr County in 2009 ( (In both cases, collectors were Rozen & Rozen).  DLD also reports in Maverick and Victoria Counties.  

Floral preferences, in addition to Argemone (DLD):  Snailseed, Baccharis


2. Lasioglossum (Dialictus) coactum.  Cresson (1872) describes this species in Hymenoptera Texana. In 1917, WIlmatte Cockerell reported Lasioglossum coactum (under the synonym Halictus (Chloralictus) coactus Cresson) in San Benito of Cameron County.  (She noted, [“m]any females at flowers of Argemone. The tegulae are punctured.” [p. 190]).

Description:  Cresson's 1872 Description reads:  “Halictus coactus, new species, female.  Green abdomen dark aeneous [greenish-gold] clothed with a short pale pubescence, head very densely and finely punctured, clypeus slightly produced, with large spare puncutres, apex broadly purplish and finged with long yellow hairs.  Flagellum pale brown beneath, especially at the tips, mandibles tipped with ferruginous, thorax much less closely punctured than the head, base of metathorax finely, somewhat longitudinally, rugose, tegulae brown, wings clothed with pale pubescence, abdomen ovate, convex, very minutely punctured, sides and apex thickly clothed with short pale pubescence, apical margin of first and second segments deeply impressed or constricted, especially that of the first segment.  Length .20 inch.  Four specimens (Belfrage)  Easily recognized by constricted segment of abdomen.”

The DLD reports this species appears in Tamaulipas; in Cameron and San Benito of Cameron County); and in the Texas Counties of Denton, Ellis (Maypearl), Fayette, Kenedy, Millam, Tom Green, Uvalde and Victoria Counties.  Inat reports this species in Texas, but not in the LRGV. This species is not included in Gibs 2010 or 2011.  

Other than the note from W. Cockerell about Argemone, no information appears to be  available on this species' floral preferences.


3. Lasioglossum (Dialictus) disparile:  Cresson (1872) describes this species in Hymenoptera Texana. In 1917, Wilmatte Cockerell (p. 190) reported a female Lasioglossum disparile with a green abdomen  feeding on a yellow composite in Point Isabel (Port Isabel), Cameron County (reported under the synonym Halictus (Chloralictus) disparilis Cresson).

The DLD shows  Lasioglossum disparile in Brownsville, Cameron County, and also in Jim Wells, Maverick and Polk Counties.  It provides a complete description of the species, as does Gibbs 2011.  Gibbs 2011 notes records for it in Bashropp, Bosque, Dallas, Denton, Maverick County (Quemado) and Wichita Counties, and in Houston.  [syn. Lasioglossum disparile (Cresson, 1872) Halictus albitarsis_homonym Cresson, 1872; Halictus disparilis Cresson, 1872; Lasioglossum (Chloralictus) albitarse_homonym (Cresson, 1872)]

Description:  Gibs 2011 calls this species “common in Texas”.   It seems unlikely that the above bee could be this species.  Gibs 2010 describes it as "medium to large" with a "head and mesosoma bluish green to golden green."  Gibbs (2010) notes that Lasolooglossum disparile  "[...]has unique band of hairs on T1 above the hair fan; these hairs are of the same type as those of the fan but are clearly separated from the fan and occur in a narrow latitudinal line across the segment; otherwise has a bit of a L. rohweri feel but in addition to the hair band has a slightly longer head; fewer lines dulling the scutum and abdomen and the fan is generally a bit more complete but still open at the top."  He emphasizes that "the female of L. disparile has a diagnostic hair pattern on the declivitous surface of T1. The strong acarinarial fan is separated from a dorsal transverse hair band by a transverse glabrous area. The male of L. disparile has the diagnostic combination of a strong genal tubercle and distinct mesepisternal punctures."  Gibb's extensive description of this species is available here:


Floral preferences:   (DLD):   solidago and other aster-faily plants, phacelia, prunus, salix (among others)



4. Lasioglossum (Dialictus) rhodognathus.  This species appears in WIlmatte Cockerell’s Collecting Bees in Southern Texas as Halictus (Chloralictus) rhodognathus. She collected a specimen from Argemone poppy, in San Benito, Cameron County.


Description:  Here is Cockerell’s description (p. 190):  “Halictus (Chloralictus) rhodognathus new species. Female.  Length about 6 mm., anterior wing 4.3 mm.; rather robust, head broad but ordinary; head and thorax green, the front and face, mesothorax and scutellum olive green; mandibles bright ferruginous, black at base; antennae black, flagellum rufescent beneath toward apex; front strongly and quite closely punctured, the punctures alike from side to side; mesothorax moder ately shining but not polished, with rather close, very distinct punctures all over; scutellum very finely punctured, the punctures of two sizes; area of metathorax microscopically reticulate and with wavy ridges, with an obscurely subcancellate effect; tegulae rufotestaceous, impunctate; wings grayish hyaline, stigma and nervures rather dusky testaceous; legs black; hind spur with three long teeth; abdomen shining black, with a faint brassy luster, the apical half thinly pruinose-pubescent; punctures excessively fine. San Benito, Texas, at flowers of Argemone (W. P. Cockerell). Resembles H. perpunctatus Ellis [Lasioglossum perpunctatum], but the wings and abdomen are quite different.”

The DHL identifies this as a Texas species, but does not give specific Texas location.


Floral preferences, in addition to Argemone:   I could find nothing anywhere else written about this species. 


Given that it's never cropped up again in any literature since Cockerell 1917, is it possible that this is the same species as Halictus connexum?



5. Lasioglossum (Dialictus) semicaeruleum.    Wilmatte Cockerell (p. 190) found females of this speciesfeeding on Argemone poppy in 1917 in San Benito, Cameron County. (She identified these under the synonym “Halictus (Chloralictus) pruinosiformis Crawford and noted “many females at flowers of Argemone. One has the front and sides of face deep blue.”

Description:  This species intense bluish coloring sets it apart from many species. Gibbs 2010 described L. semiceruleum very thoroughly,  He notes:  "Diagnosis. Females of L. semicaeruleum can be recognised by diagnostic combination of a wide head (length/width ratio = 0.94–0.97), coarse mesoscutal punctures that are moderately dense on central disc (i=1– 2d), coarse mesepisternal punctures (Fig. 207D), hyaline wings with pale venation and pterostigma, strong anastomosing rugae on metapostnotum (Fig. 207E), blue or green metasomal terga with apical margins brownish yellow, strong T1 acarinarial fan, and T3–T4 with abundant white tomentum."

Gibs' 2010 description, which is lengthy, can be found in its entirety here:

T.D.A. Cockerell described this species in 1919 [as Halictus glaucovirens], in "The Bees of the Rocky Mountain National Park (Hymenop.)," Entomological News, vol. 30, pp. 286-294.  He described the female as follows:  " Like H. pruinosiformis Crawf. [ later called Lasioglossum semicaeruleum] , but head elongated as in H. pruinosus Rob. [Lasioglossum pruinosum], from which it differs by the darker flagellum, and more strongly and less densely punctured mesothorax, with a shining sparsely punctured area of each side of the middle. The insect is glaucous green, with pure white pubescence; wings hyaline, stigma pale yellowish, subcostal nervure black. The thorax is not so robust as in pruinosus."

The DLD reports this species in Edinburg, Hidalgo County, in 2010.  Bug Guide has a record for this species El Paso County.  Inat records it in Huntsville.  Gibbs 2010 records it in Denton Co.  



Floral preferences, in addition to LRGV Argemone:  Gibs 2010 notes the following:  ASTERACEAE: Helianthus annuus, H. petiolaris, Pectis papposa, BERBERIDACEAE: “Odostemon”, CACTACEAE: Carnegiea gigantea, CAPPARACEAE: Cleome serrulata, FABACEAE: Dalea candida oligophylla, Parkinsonia microphylla, LOASACEAE: Mentzelia pumila, PAPAVERACEAE: Argemone pinnatifida, POLEMONIACEAE: Polemonium, SCROPHULARIACEAE: Penstemon linarioides coloradoensis, ZYGOPHYLLACEAE: Larrea tridentata. Comments. Abundant. 



OTHER LASIOGLOSSUM (DIALICTUS) SPECIES OF TEXAS -18 species (in addition to the five above)

I compiled this list from the sources noted above.  They are a little heavy on eastern species and light on western and border species, but I thought if might be supplementally helpful.  None of these have been documented in the Valley by any source I know of.

Lasioglossum (Dialictus) apopkense.  Gibs 2011, DLD.  Nagadoches and Hardin Counties.

Lasioglossum (Dialictus) bruneri:  DLD, I-nat. Hardin County.

Lasioglossum (Dialictus) coeruleum.  Gibs 2011, I-nat. Dalhart, TX.

Lasioglossum (Dialictus) coreopsis.  Gibs 2011,, DLD.  Denton & Hardin Counties.

Lasioglossum (Dialictus) creberrimum. Gibs 2011, DLD.  Hardin & Tyler Counties.

Lasioglossum (Dialictus) floridium.  Gibs 2011, DLD.  Segoville.  Bashrop, Donley, Monroe and Nagadoches counties.  

Lasioglossum (Dialictus) harti. Gibs 2011, DLD.  Liberty, TX.  Dewitt & Hardin Counties.

Lasioglossum (Dialictus) hunteri.  DLD.  Texas City, Galveston County (lat/long given), Quemado in Maverick Co., Big Bend National Park.

Lasioglossum (Dialictus) illinoense.  Gibs and the DHL identify this as a Texas species, in Bosque County.

Lasioglossum (Dialictus) imitatum.  Cresson (1872) describes in Hymenoptera Texana. Gibs 2011, DLD, I-nat.  Galveston, Maypearl.  Bosque & Gonzalez Counties.

Lasioglossum (Dialictus)  lineatulus.  DHL.  Specific Texas location not given. Not noted in DHL map for species, but noted in association with on general DHL Halictus page (

Lasioglossum (Dialictus) longifrons.  Gibs 2011, DLD.  Galveston.

Lasioglossum (Dialictus) mesillense.  DHL. Specific Texas location not given.  Noted on general DHL map and  Halictus page (

Lasioglossum (Dialictus) pilosum.  Gibs 2010, I-nat. NE Texas.

Lasioglossum (Dialictus) reticulatum.  Gibs 2011, I-nat. Fayette &  Nagadoches Co.

Lasioglossum (Dialictus) tegulare.  Gibs 2010, I-nat. Houston.

Lasioglossum (Dialictus) tarponense.  Gibs 2011, DLD.  Nagadoches Co.

Lasioglossum (Dialictus) zephyrus.  Cresson (1872) describes in Hymenoptera Texana. Gibs 2011, DLD, I-nat.  NW Texas.