The crumbling magnesian limestone cliffs along the Durham coast are excellent places to find these tiger beetles Cicindella campestris. There were scores of them running over the rock-falls at the base of the cliffs at Hawthorn Hive today.
Their exoskeletons are beautifully iridescent, shot-through with a purple sheen when the sunlight strikes them and their movements are distinctive too, rapidly running over the soil surface in a state of constant agitation and often taking to the air for short flights when they’re disturbed.
These insects are ferocious hunters, like most ground beetles, running down their prey and impaling it on needle-sharp jaws (double-click bottom image for a better view of these). When she was a child my daughter made the mistake of catching one of these jewel-like beetles in her cupped hands and instantly regretted it when it sunk its jaws into her finger. Twenty years later, she still remembers the pain it inflicted. Their jaws have a very wide gape and these pictures reveal a possible reason - the male uses them to cling onto the female when they're mating, grasping her at the narrow junction between her thorax and abdomen. The jaws of the larvae, that live in vertical shafts in the sandy soil, are equally impressive and are held level with the soil surface, ready to snap shut on any small insect that blunders too close to the burrow entrance.
For some pictures of another ground beetle in unfortunate circumstances, take a look at http://cabinetofcuriosities-greenfingers.blogspot.com/2009/07/food-that-fights-back.html
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