I haven’t posted any ants for awhile. So here is a pair of little carpenter ants from the back yard:
Most people in North America think of carpenter ants as the big hairy black things that damage houses by chewing through older and dry-rotted wood. That’s certainly true of Camponotus pennsylvanicus, the eastern black carpenter ant.
But the genus contains many smaller and less conspicuous species that nest in pre-formed cavities and plant stems, foraging for scraps and honeydew and generally bothering no one. The two pictured here are both abundant in our garden.
Researchers have started paying more attention to Camponotus in recent years, for two reasons.
First, it turns out that these ants’ bellies are full of a bacterium called Blochmannia. Blochmannia are basically little Jesus bugs, converting
water into wine urea into essential amino acids and allowing their host ants to thrive on diets where other ants flounder. So there’s great potential for turning this ant/bacteria tryst into a coevolutionary model system.
Second, Camponotus lacks a metapleural gland. Why does this matter? One of the incredible things about ants- and one reason to study them- is their antibiotic prowess. Ant colonies inhabit warm, damp, moldy crevices, places where pathogens should abound. Yet these social insects are quite good at keeping their pests under control thanks to a battery of glandular secretions and associations with friendly bacteria. The metapleural gland is one structure suggested to have an antibiotic function, and how Camponotus survives without one will be an important consideration in studies of ant social immunity.