Amara is a large genus of carabid beetles, commonly called the sun beetles. Many are holarctic, but a few species are neotropical or occur in eastern Asia.
These ground beetles are mostly black or bronze-colored, and many species have a characteristic “bullet-shaped” habitus, as shown in the photos, making them taxonomically difficult. They are predominantly herbivorous, with some species known to climb ripening grasses to feed on the seeds.
Carabus nemoralis (commonly called the “Bronze Carabid”) is a ground beetle common in central and northern Europe, as well as Iceland and Canada. While native throughout North America. Has one breeding period in the spring with eggs hatching in autumn of the same year.
These are fast-moving, agile beetles with powerful legs and long antennae. The species normally seen indoors are 2-3 cm long and black or brownish. Only a few of them can fly, and in some species the elytra which cover the abdomen are fused together.
Most carabid beetles are predatory, feeding on worms, slugs and insects, and some species have been released in American forests to control injurious moth larvae. These beetles handle their prey in a characteristic manner, for much of the digestive process takes place outside the animal. They regurgitate dark brown digestive juices on to the prey, which is thus paralyzed. Its tissues gradually become liquefied and this liquid is then sucked up.
Carabids or ground beetles spend the day hidden among vegetation, under stones, behind loose bark or in similar places. Several species are very common in gardens and fields, and these may find their way into houses when they are running around at night in search of food. As they prefer damp places they are frequently seen in cellars.
If it feels threatened a carabid may regurgitate on to a finger, and they also have another form of chemical warfare. If one is seized it will often produce a secretion with a sharp, sour smell, which remains on the fingers for a long time. The secretion is produced by certain glands at the rear end of the abdomen; it contains various organic acids, and probably serves as a means of defence against attackers. Some mammals which normally eat insects are very sensitive to strong smells. to Europe, it has been introduced to and is expanding its range throu