Small bombardier beetle
| Small bombardier beetle | ||||||||||||
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| Systematics | ||||||||||||
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| Scientific name | ||||||||||||
| Brachinus explodes | ||||||||||||
| Duftschmid , 1812 | ||||||||||||
The small bombardier beetle ( Brachinus explodens ) is a ground beetle of the subfamily of the bombardier beetles (Brachininae).
features
The animals are 4.9 to 7.5 millimeters long, making them the smallest bombardier beetles in Central Europe. The body is colored red except for the wings . The latter have a metallic green or blue-green color, are ungrooved and have close-fitting hairs. The scutellum is red, the antennae are darker in color on the third and fourth segments, otherwise also red. Like all bombardier beetles, they also have an explosion chamber at the rear end of their abdomen, which they use to defend themselves against predators (see bombardier beetles ).
Occurrence
The animals occur in southern and central Europe , except in the Alps , and in Asia , east to Siberia . They love warmth and live in lightly overgrown forests, hedges, on dry grassland and fields and can be found under stones. They prefer low altitudes and can occur locally in high population densities.
development
The eggs are laid individually on soil particles in late spring. They are whitish and slightly opaque. Their shape is oblong oval with a longitudinal diameter of 0.88 millimeters and a transverse diameter of 0.39 millimeters. The hatched larvae have the shape typical of ground beetles, elongated with well-developed legs. They hatch white and darken a little in the first six hours. You immediately go in search of a beetle doll. If they are successful, they will occasionally continue the search. With increasing age, the tendency to stay with the found doll increases. This happens on average in less than 24 hours (the times given relate to a laboratory test). Only species of the genus Amara are currently known as hosts . As soon as a pupa is accepted, the larvae start to feed on it. They attack body attachments first. They bite through the outer skin of the doll in several places and lick up the escaping liquid. It takes an average of 3.3 days to molt to the second larval stage. In the second and third instar, the larvae resemble caterpillars, they are white and have poorly developed legs. In the first and second larval stage only the hemolymph of the pupa is ingested, in the third and last larval stage the tissue of the pupa is also eaten. The pupa dies during the second larval stage when the larvae attack the intersegmental membranes. The second larval stage lasts an average of 2.4 days. In the third larval stage, the host pupa is completely eaten up, after which the larvae remain immobile for several days next to the eaten pupal shell. The feeding phase of the third and last stage lasts an average of 1.4 days, the subsequent rest phase 3.5 days. The doll already shows the shape of the finished image . The imago hatches after an average of 9.4 days, the overall development after hatching from the egg takes twenty days.
literature
- Ekkehard Wachmann , Ralph Platen, Dieter Barndt: Ground beetles - observation, way of life . Naturbuch Verlag, Augsburg 1995, ISBN 3-89440-125-7
- Jiři Zahradnik, Irmgard Jung, Dieter Jung et al .: Beetles of Central and Northwestern Europe. Parey, Berlin 1985, ISBN 3-490-27118-1 .