Subfamily FORMICINAE
Tribe CAMPONOTINI

Camponotus (Camponotus) chromaiodes Bolton

Camponotus chromaiodes, profile view of major worker - with typical reddish coloration on propodeum, petiole and legs. (click image to enlarge).
Camponotus chromaiodes, profile view of major worker - with coloration more similar to C. pennsylvanicus. (click image to enlarge).
Camponotus chromaiodes, full face view of a major worker. (click image to enlarge).
Camponotus chromaiodes, dorsal view of gaster. Note the pubescence extending well past the edges of the tergites; more than half of the length of those hairs reach the next tergite (Compare to C. pennsylvanicus gaster). (click image to enlarge).
Microdon larvae and Camponotus chromaiodes
Microdon larvae
Camponotus chromaiodes workers under bark of a dead Pinus taeda log with Microdon sp. larvae (Syrphidae) [larvae in lower left corner].
Microdon sp. larvae found with C. chromaiodes in colony under bark of pine log.

Introduction
Ants in the genus Camponotus are collectively known as carpenter ants because some species nest in wood, including man-made structure. This genus includes some of the largest and most common ants in the world, and they are found in all biogeographical regions (Bolton, 1995).  More than 900 species of Camponotus are known worldwide, with 50 species reported from the United States (Hanson and Klotz, 2005), and 20 species found east of the Mississippi River (Deyrup, 2003; Smith, 1979). 

Species in this genus are variable in size with workers ranging in size from 3 to 15 mm or more in length and queens (also referred to as females) of some species attaining a length of 19 mm or more. Many species are polymorphic. Workers have a 12-segmented antenna that lacks an apical club. Antennal fossae do not touch the posterior border of the clypeus. Ocelli are not present on the heads of workers. The workers of most species have an indistinct metanotal suture between the promesonotum and the propodeum, although this suture is present in C. sexguttatus and some members of the subgenus Colobopsis.  Those species that lack the obvoius and deep metanotal suture have the shape of the alitrunk in a smoothly curved arc (as seen in profile). 

Camponotus chromaides is in the subgenus Camponotus, which includes some of the true carpenter ants that nest in wood. Species in this subgenus are large ants with workers ranging approximately 6-14 mm in length.  The clypeus is ecarinate to only scarcely carinate, antennal scapes are not flattened at the bases, clypeal fossae are well developed, and the heads of major workers are usually broader than long.  This subgenus includes three species in Mississippi. 

Identification
Camponotus chromaiodes is sometimes called the red carpenter ant, because of the red coloration often found on the rear part of alitrunk and legs. This is a large species with major workers having an overall length of 6-13 mm. The posterior part of propodeum, the petiole, the base of gaster, and legs are usually reddish, and the rest of the body black (color is variable, sometimes there is less red present). Appressed hairs found on gaster are more numerous and long, and they overlap the posterior edges of the gastral tergites (this is best seen in dorsal view) by at least half of their lengths and are golden in color. The two top photos above show two variations of major workers of Camponotus chromaiodes (formerly called C. ferrugineus). It is not unusual to see the darker form such as is shown on the above right and it is sometimes difficult to separate this color form from C. pennsylvanicus.

Biology and Economic Importance
Nests are often found in and beneath rotting logs and stump with galleries typically extending into soil. They also nest in dead standing trees or in moist or otherwise degraded wood in buildings. These are very common ants in Mississippi and can have very large nests with many thousands of workers. Alates have been collected throughout the summer and into early Fall in AL and MS.

The ant loving cricket, Myrmecophilus pergandei and Microdon sp. larvae (Syrphidae) have both been collected in C. chromaiodes colonies in this region.

Distribution

Literature Cited

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