This section is from the book "Commercial Gardening Vol3", by John Weathers (the Editor). Also available from Amazon: Commercial Gardening, A Practical & Scientific Treatise For Market Gardeners.
At least four kinds of ground beetles, often called Bat Beetles, attack ripening and ripe strawberries.
The commonest is the Red-legged Strawberry Beetle (Harpalus rujicomis), which is 1/2 in. long, black, with red antennae and legs, the wing cases with faint lines upon them and covered with fine golden-grey pubescence; beneath are a pair of fully developed wings.
Another, Pterostichus vulgaris, is black, with black legs, and has no wings, and is 2/3 in. long.
These beetles have all very similar habits. They are nocturnal and crawl or run about on the ground, but the Red-legged Harpalus may fly. During daylight they hide away in crevices in the ground and under stones, etc. They frequently form circular openings to the surface like earthworms. The beetles occur in May, June, and July. They lay their ova in the soil, and the active larvae feed upon slugs, insects, earthworms, etc, in and upon it. The larvae have six long legs, prominent head with large sickle-shaped jaws, and the back of their bodies protected by hardened plates, and on the last segment are two pointed, horn-like processes, and below a single extensile fleshy kind of proleg. The beetles eat the skin of the green fruit, leaving many of the seeds; but when the fruit is ripening they feed on the seeds, and countless numbers may be found on the ground in the beds that are invaded by these beetles. Many Carabidae are purely carnivorous.
The beetles are easily trapped by sinking jam pots or pudding basins in the soil here and there, and placing in them pieces of meat and sugar water. The beetles are attracted to these baits, fall in, and are thus caught.
Moles and Hedgehogs feed upon these beetles. The latter do much good in Strawberry beds in this respect.