Sphex

Sphex, a genus of hymenopterous insects of the family Sphegidae, closely allied to the true Wasps (Vespidæ). The Sphex wasps are solitary in habit, and there are no workers as in the social forms. The female hollows out, at the end of a long passage, three or four chambers, in each of which she deposits an egg and a store of food for the larva she will never see. The food consists of grasshoppers or other insects, and Fabre gives a minute account of the way in which the Sphex attacks her victim, and, after a long and violent struggle, throws it on its back and stings it in the neck and between the thorax and abdomen, each time piercing a ganglion. The insect, completely paralysed, but alive, and therefore not liable to putrefaction, is then dragged to the mouth of the nest, where it is relinquished for a short time, while the wasp enters alone to see that all is right. So automatic is this habit of reconnoitring that if the grasshopper be removed to a little distance the wasp drags it back to the same spot and again enters alone. This was tested by the observer forty times in succession, and each time the wasp paid her preliminary visit of inspection. But, in proof that she is not wholly the slave of habit, it should be noted that when Fabre substituted a fresh grasshopper for the paralysed one she at once perceived the difference, and proceeded to attack and sting her recalcitrant victim. Four paralysed insects are placed in each chamber, which is sealed up as it is finished. When all are full the mouth of the passage is also closed, and the nest is abandoned. See WASP.