There are many species of Ground Beetle (the total number being 350,000) which all belong to the same order, making them the largest species of winged insect. They have hard wing-cases, which cover the greater part of their body, these wing cases are actually the first pair of wings with the second membranous pair beneath them. They are found in variable colours from dark black to metallic green, violet or bronze. These beetles are nocturnal predators.
Size, Shape and Colour: 15-25mm in length. The head points straight fowards and may be inclined downwards, the mouth parts are of biting type and the legs are well adapted for swimming, burrowing and jumping. May have ridged wing cases. The most common species is shiny and black.
Biology: The females lay the eggs singly at the beginning of summer, some beetles excavate burrows for their larvae others wrap the eggs in cocoons. Some even roll up leaves to form a capsule for them. The larvae are dark coloured and grow to a length of up to 30mm. They moult approximately 5-7 times before pupation. Young beetles will appear at the end of July or in August. There is usually just one generation per year, however two can occur depending on weather conditions.
Preferred Foods: In most cases the larvae feed from the same food matter that the adult beetle would feed, this consists of plant matter, pollen, sweet juices and insects ranging from small insects to worms and caterpillars.
Habitat: The beetles like plenty of moisture and will always choose damp retreats, the most favourable being under stones, damp moss, under felled trees and in wet leaves. When disturbed these beetles will emit a odour, this is simple a defence mechanism. They can be also be found indoors, however this only occurs when looking for shelter. These beetles hibernate during the colder months.