"Carpenter ants" and "sugar ants" - everyone is familiar with these!
These two are the most popular common names for the very widespread and extremely complex genus Camponotus. Carpenter ants are generally known for their great appetite for sugars. However, the genus Camponotus is far too frequently generalised by the media as the annoying pest which causes damage to wooden structures. This is mostly the case for some species from the subgenus Camponotus. Other species of other subgenera are generally harmless and many are not yet well known. I would like to change that.
And yes, you read it right: the subgenus Camponotus, being a subgenus of the same name within the genus itself. But what does that mean exactly? And what even is a subgenus? In this article I will cover a couple subgenera of Camponotus in simple terms. This article may serve as a guide for identification too!
Chapter 1. Taxonomy
Each living organism is categorised into a scheme of numerous classification terms. Ants are categorised into subfamilies, tribes, genera, subgenera sometimes, species groups, species and sometimes even subspecies. Let's take a look at an example below.
Categorising Camponotus barbaricus xanthomelas, which is a subspecies of C. barbaricus native to Northern Africa, will give the following:
Family: Formicidae (= Ants)
Species: Camponotus barbaricus
Subspecies: Camponotus barbaricus xanthomelas
Shortly: C. barbaricus xanthomelas
"At present, more than 1500 species and nearly 500 subspecies belonging to 45 subgenera are described (Bolton, 2012) and it could well be the largest ant genus of all." (Source: Antwiki) - referring to Camponotus
Information in this post is based on my point of view from knowledge I gained from trusted sources being Antwiki and Antweb. This article is made as a basic guide for Camponotus identification with the goal of sharing useful knowledge for the general public. Any individual has the right to disagree with some points mentioned. But I would like to keep things friendly and discuss improvements privately. Thank you for your time. Now let's start!
Major worker of Camponotus vagus
The first subgenus of the genus Camponotus, which is also referred to as Camponotus sensu stricto, is commonly known as the "true carpenter ants". Most species of this subgenus prefer to nest in wood, therefore the common name. A couple of species in USA for example are a major pest, causing big property damage to wooden structures (see image below). Mature colonies are generally big.
Most species of this subgenus are big in size and generally bulky. Majors and queens have big rounded heads. Queens, e.g. those of C. novaeboracensis in the example below, are pretty chunky and generally monogynous.
Queen of Camponotus novaeboracensis
Nest entrance of Camponotus compressus
Commonly known as "slim carpenter ants", this subgenus may cover most species from the genus Camponotus. Species of this subgenus nest in soil, sometimes partially in wood. Mature colonies of a lot of species are known to be large in size. Species of this subgenus vary from small to big in size and are slim with long legs and antennae. Majors and queens have big traingular heads. The minors are elongated, often with a small oval or diamond shaped head. Queens, like C. consobrinus in the example below, are slighlty less bulky than those of Camponotus sensu stricto. They are generally monogynous. One of the exceptions is C. nicobarensis, which can tolerate a few queens in some localities of its distribution. Many species of Tanaemyrmex are notorious for being xerothermic (= adapted to / benefitting from heat), very colourful
Queen of Camponotus consobrinus
Social parasites of Camponotus
Despite the genus Camponotus containing approximately 1.500 species, currently Camponotus universitatis and Camponotus ruseni (Karaman, 2012) are the only known social parasites of Camponotus that have ever been discovered as of yet. C. universitatis and C. ruseni are inquilines in the nests of Camponotus aethiops. C. universitatis can also live with hosts of Camponotus pilicornis. Both species are a permanent parasite without slavery (Tinaut et al., 1992; Guillem et al., 2014). Both are rarely found. As both species are in the subgenus Tanaemyrmex, I found them interesting to include in this article
Two images, above and below, show a queen and the workers of C. universitatis for reference. Both are small and dark coloured.
Worker polymorphism in Camponotus cruentatus
Commonly known as "silky carpenter ants", this subgenus is comparable to the subgenus Tanaemyrmex. Species of Myrmosericus nest in soil. Mature colonies are big in size. Ants of this subgenus are a slightly bulkier version of Tanaemyrmex, with rounder heads. Colonies are monogynous. Some species and some populations of C. nicobarensis can be lightly polygynous. Many species of Myrmosericus are highly aggressive.
Queen and major workers of C. dolendus
Species commonly sold as 'Camponotus auriventris' on the market are also of the subgenus Myrmosericus, similarly in appearance to C. parius. However, C. auriventris has in reality never even been sold because of how rare it is to find queens in the wild. This misinformation developed some years ago when Chinese ant-stores couldn't properly identify this species so they picked a random species name - not looking at the subgenus first - I would imagine. Moreover, this popular species is much smaller and looks very different from the true C. auriventris, which is of the subgenus Myrmosaulus. I will pick up on this topic later.
Queen & worker polymorphism of Camponotus dalmaticus
Commonly known as the "cleft-lip carpenter ants", species of Myrmentoma make small nests in soil or wood. Mature colonies are small in size at rarely up to 1000 workers - oftenly they are made up of just a few hundred individuals. Ants of this subgenus are small, slim and polymorphism is less pronounced in comparison to the previously mentioned subgenera. Most queens are <11 mm in lenght and slim. Colonies are monogynous to lightly polygynous. Workers of Myrmentoma are not aggressive, they are opportunistic scavengers. A few species of Myrmentoma have adapted mimicry of other ant species to blend in. This allows for even more foraging opportunities on foreign territory.
Mimicry of Camponotus lateralis around Crematogaster scutellaris
Queen and workers of Camponotus mutilarius (common name: 'C. xiangban')
Commonly known as "flat-back carpenter ants", this subgenus is characteristic for workers having quite flat tops of their thorax. Species within this subgenus are medium to small in size, with caste dimorphism somewhat marked. The head of majors is large, wider than long. The body is usually covered in a lot of small setae. On some species, such as on C. mutilarius in the image above, the setae are long and well pronounced.
Major workers of Camponotus sericeus doing trophallaxis
Queen and workers of Camponotus singularis
Commonly known as "monster-head carpenter ants", this subgenus truly lives up to its name! The head of majors is large and generally with lateral margins rounded. Species of this subgenus are large to medium sized with pronounced dimorphism: a clear distinction between the minor and major caste, with no medium sized workers in between. The most popular species is C. singularis ofcourse, known for their large red heads and silver body. Another bit less known species of this subgenus is C. suffusus.
All species of Myrmosaulus share a similar body shape and size, which brings us to a callback about C. auriventris. Their latin name refers to their golden coloured body. The true C. auriventris are very similar to C. singularis, so to mix them up with species similar to C. parius (Myrmosericus) should be impossible - but somehow this became possible due to spreading of false information by Chinese sellers. Everyone who sells unknown Myrmosericus species under the false name 'auriventris' should stop. And give the unknown species a new unique name. Otherwise misinformation will keep on spreading beyond the return point...
Queen and workers of Camponotus auriventris
Two majors fighting: Camponotus singularis VS Camponotus auriventris
Queen of the similar Camponotus holosericeus (common name: 'C. chinensis').