Tuesday, January 13, 2009

Digger Wasp
Digger wasps are from Order Hymenoptera which includes insects like wasps, bees and ants. This is the third largest order after beetles and flies that had evolved about 155 million years ago. The digger wasp first prepares a burrow in a suitable spot, and then starts digging. When a little hole is made, then she enters it and comes out carrying soils between her curved forelegs and her head, repeating this till there was a considerable heap of soil. This heap she then demolishes by standing and kicking it away with her hind legs, leaving no evidence of its excavation. Before beginning hunting she makes a complex series of short flights around and above the nest site, fixing in her mind a visual pattern of its location and of prominent landmarks by which it can be locates from long distance. A major disadvantage of preparing the nest in advance lies in the necessity of transporting the prey when it is obtained at some long distance. Many times wasp hunts for larger prey, sometimes heavier than herself, and may have a long and difficult task dragging the load over rough terrain and through dense, tangles vegetation.
The main prey of this wasp is the caterpillars of butterflies and moths, sometimes far heavier than the wasp herself. On finding such victim she stings it a number of times, puncturing quite accurately. The wasp has an instinctive knowledge of the caterpillar’s anatomy; it is undeniable that in the most of instances she does succeed in paralyzing the prey and not killing it. She grasps the caterpillar in her jaws and straddling it with her long legs, drags and carries it to the nest. The way may be long and tortuous, so that she may occasionally heave to leave the prey and make on orientation flight to set herself on the right track. Eventually she reaches to the prepared burrow and drags the caterpillar down to the chamber. Laying an egg on it, she leaves it and starts filling in the opening of the nest.
Yuwaraj Gurjar.