Tiger Beetle - A Study In Ecology

it is spring the cherry tree opens its blossoms to the bee its roots sip food from the warming soil new life is everywhere to one small but ferocious insect spring brings certain special challenges buried up to now and motionless it must suddenly be ready for a world it has never seen and so sensing the sun it thrusts itself up to live out the days of its short harsh life a life of ancient endless patterns and a fascinating relationships to other living things the tiger beetle greets the world with some well-developed instincts to catch and subdue its food to find water and in time a mate to clean itself with equipment very well designed for the purpose it seems well designed for all the things it must do large bulging eyes will detect enemies and prey long slender legs will permit sudden bursts of speed protective coloration will enable it to lie in weight unseen the beatles first meal yet quickly recognized and quickly captured the predator having rubbed its catch briskly on the ground very systematically begins to rotate it crush it consume it the process is an efficient one the large primary mandibles do most of the work moving in conjunction with the second smaller pair the beetle actually swallows only the softer tissues later it will expel the harder exoskeleton this meal will not end until the prey is completely consumed meanwhile the voracious hunter is ever alert to danger and back along its wing areas the cleaning process appears to continue just as instinctive and just as efficient is the beatles response to the problem of thirst if there is no water in sight the insect finds it anyway by sampling the soil lump by lump and when it detects a damp area burrowing its mouth parts into the earth the sun's light and warmth stimulates the beetle to activity a constant cycle of eating drinking and cleaning interrupted only by danger and by the search for a mate the insect can fly rapidly but it seldom travels very far for the total area of its world is very small as it moves slowly through the stems of the dead grass its protective coloration makes it almost invisible to possible victims in this case a small jumping spider which happens to be out of reach as the predator climbs up to stalk the spider we catch a glimpse of the detail and coloration that markets underside the beetle is part of a realm in which there are over a million and a half separate forms of life and the ways in which they differ in performing the same functions are often fascinating the skipper butterfly when it seeks food uncoils a delicate tube-like siphon and gently sips nectar from an orchid no not a snake a slow worm a legless lizard and not particularly impressed by the fierce looking beetle nor interested vice versa the slow worm represents neither food nor foe nearby a distant relative the slow lumbering chaffer beetle firm in its foothold on the slender grass it tests the air with its plate-like antenna before taking flight warmed by the air of early spring more and more creatures crossed the beetle's path hiding in a sprig of wild thyme the beetle watches a lacewing perched on a small leaf getting ready to lay a single green egg the lace wing releases a drop of secretion from her overposition and draws it up to form a stalk it hardens instantly a sturdy resting place and here the egg will sit until it hatches out of the reach of predators like the beetle and its kin nearby a blossoming rock rose attracts a hoverfly which looks a great deal like a honeybee later we will see what happens when the beetle encounters a real bee quite another story a dainty grasshopper nymph and down below a rather one-sided battle in progress how do you deal with something that can tuck its wings and legs and antennae away and leave nothing to grab but a smooth hard round shape the beetle is often called the tiger of its little world but the ladybird seems to have nothing to fear has the beetle learned that further attacks would just be a waste of time now the beetle is hungry and to certain segments of the insect world very dangerous but shape as we've seen can protect and so can coloration camouflage seems to be doing the job here but the beatles hunt for food is finally successful for there is at least one common insect with almost no defenses a hungry beetle has been known to eat 14 at a time one after another whether the ants are aware of the beetle's presence is an interesting question but in any case they are no match for its skill and speed an ant is obviously much tougher than a caterpillar but it meets its fate in much the same way crush and swallow the softer parts and spit out the skeleton something like eating lobster after the meal a few drops of rain water from a green leaf now a different sort of encounter a real be this time interesting prey perhaps but with defensive equipment of its own that may well be a match for the beatles strength and speed the battle is short and violent it ends not with victory but in what appears to be a tie nearby another easily recognized member of the insect world sits busily preening body wings and sensory organs the beetle once more on the hunt pays no attention despite its menacing look the grass snake has no poisonous fangs its sensing device by the way is its delicate fork tongue it lives on a different sort of diet and it shows no interest in the beetle what's this the eye of a ferocious creature of some sort not quite the fragile defenseless butterfly wears what is known as an eye spot the beetle seems fooled or perhaps just not interested now the beetle passes an interesting example of conservation in nature not a dragon but an ordinary caterpillar it may in short order entirely consume this leaf but the waste it produces falls down to fertilize the soil in the very same spot suddenly the beetle detects a female of his own species unlike many insects the tiger beetle spends no time in courtship mating begins almost at once and lasts about an hour during mating the normally active and aggressive beetle remains at rest unresponsive to prey and perhaps easily attacked in this unusual photographic sequence the male reproductive organ is clearly visible entering the female cavity after the male has withdrawn the female drives him off and when the time comes to lay her eggs some hours later she brings some fascinatingly designed reproductive equipment into play having found soil of a suitable type she extends a remarkable telescopic overpositor with its four strong hooks that can bite into the soil and digs an individual depression for each egg before releasing it after the egg is laid another instinct takes over for the delicate capsule must be protected from both its living enemies and the elements and so the egg quickly disappears from view she will not live much longer but her eggs are in the ground and there they will stay until the warming rays of the sun signal the coming of another spring you