Camponotus laevigatus

Mackay (2019) discovered that the types of this species do not match the common shiny, glossy specimens that have been referred to as C. laevigatus for over 160 years. He proposed that this common, shiny species is actually a separate species, which he named Camponotus laevissimus. Most literature (probably except for the original description) as well as specimens in museums labelled as C. laevigatus actually refer to C. laevissimus. In fact, no other specimens of C. laevigatus besides the type series (in The Natural History Museum (London)) are known.

Compare with Camponotus americanus, Camponotus castaneus, Camponotus herculeanus, Camponotus johnsoni, Camponotus modoc, Camponotus novaeboracensis, Camponotus laevissimus, Camponotus quercicola.

Camponotus laevigatus is easily separated from most of the other North American species, as all surfaces of the major and female are black, shiny, but completely covered with coriaceous sculpture, or with transverse striolations on the dorsum of the gaster. Both completely lack erect or suberect setae on the antennal scapes. The cheeks have a few erect setae. The clypeus is shield-like without a carina.

The minor worker was not found and male is unknown.

Comparisons
Camponotus laevigatus can be easily separated from Camponotus laevissimus (SW Canada, western US), as it lacks erect, prominent erect and suberect setae on the antennal scape, which is bristly with small erect setae in C. laevissimus. It can be distinguished from Camponotus herculeanus (S Canada, most of US), as it has an elongated scape, which extends well past the posterior lateral corner of the head.

It could not be confused with Camponotus novaeboracensis (S Canada, most of US) as the mesosoma of C. laevigatus is black, and shiny laterally, not red or reddish black and dull as in Camponotus novaeboracensis.

Several species are shiny, even more so than C. laevigatus, but are either light to medium brown and from eastern USA as far west as Texas (Camponotus americanus, Camponotus castaneus) or longer than 1 cm (Camponotus johnsoni from Baja California is smaller and the scapes barely reach the posterior lateral corner of the head).

Camponotus laevigatus is very similar to Camponotus modoc (S Canada, western US, N Mexico) and Camponotus quercicola (California), but can be separated as it apparently lacks appressed setae on the dorsal surface of the gaster (based solely on the lectotype) but are present on the gasters of the workers of C. modoc and C. quercicola. Camponotus modoc is very common and widely distributed, the other two species are rarely collected.

Camponotus quercicola (southern CA, northern Baja California) is nearly identical to C. laevigatus. The major workers differ in that C. laevigatus has few or no erect setae on the cheek (several present in C. quercicola) and the side of the mesosoma of C. laevigatus is shinier. The sides of the head are approximately equal in shininess and the remainder of the sculpturing, pilosity and color are identical.

Distribution
Known only from an unknown locality in California, United States.

Distribution based on Regional Taxon Lists
Nearctic Region: United States.

Biology
Nothing is known concerning the biology of this species. Previous literature mentioning this species are referable to Camponotus laevissimus.

Nomenclature

 *  laevigatus. Formica laevigata Smith, F. 1858b: 55 (w.q.) U.S.A.
 * Combination in Camponotus: Roger, 1863b: 5.
 * Combpination in C. (Camponotus): Forel, 1914a: 266.

Taxonomic Notes
It is unexpected that a species of Camponotus from California would be known from only a major worker and queen collected in the mid-1800's, and never encountered again. As the specimens are housed in The Natural History Museum, along with specimens from throughout the world, it is possible that these specimens were mislabelled and are not actually from California. Unfortunately there is no direct evidence to support (or refute) this possible explanation for the apparent rareness of this species. Only when the genus is better understood may it be possible to match these specimens with species from other parts of the world and potentially determine its true identity.

Major worker measurements (mm): HL 3.10, HW 3.06, SL 2.78, EL 0.73, CL 0.93, CW 1.20, WL 4.24, FFL 2.50, FFW 0.85. Indices: CI 99, SI 90, CLI 130, FFI 34.

Mandible with five exposed teeth (closed); clypeus with no evidence of carina, anterior border nearly straight and slightly crenulated; head narrowed anteriorly, posterior border nearly straight; eyes not reaching sides of head; scape extending well past posterior lateral corner of head; propodeal spiracle slit-shaped; petiole narrow when viewed in profile.

Anterior border of clypeus with few erect setae, clypeus with few setae along borders, few small erect setae on cheeks, lacking on sides of head and along posterior border, ventral surface of head with 6 erect setae, scapes without erect or suberect setae, except at apex, dorsopropodeum nearly without nearly erect setae, except for area between dorsopropodeum and posteropropodeum, tibiae with few suberect setae located on lower half or near spur, dorsal border of petiole with eight erect setae; appressed setae very sparse or absent on all surfaces.

Mandibles completely longitudinally rugose, with few scattered coarse punctures, dorsum of head mostly finely punctate or coriaceous, sides of head coriaceous, moderately glossy, dorsum of mesosoma coriaceous, weakly shining, sides of mesosoma coriaceous, moderately shining, gaster with transverse striations moderately shining. Black, legs dark brown.

Female measurements (mm): HL 3.34, HW 3.36, SL 2.72, EL 0.84, CL 1.14, CW 1.31, WL 5.70, FFL 2.84, FFW 0.84. Indices: CI 101, SI 81, CLI 115, FFI 29.

Mandible with six teeth; anterior border of clypeus nearly straight, crenulated, clypeal carina absent; sides of head narrowed anteriorly; posterior border nearly straight; eyes nearly reach sides of head; much of dorsum of mesosoma destroyed by badly degraded pin; part of posteropropodeum and anterior face of petiole with glue; gaster and most legs missing.

Pilosity similar to that of major worker, except cheeks and surface of clypeus with more setae, ventral surface of head with several setae.

The sculpturing and color are similar to that of the major worker.