Nor do we, in gathering evidence for the evolution of the instincts of these wasps, need to rely entirely upon our own observations. Fabre himself gives many facts which point in the same direction, but he draws a line between those actions which are the result of mechanical and unvarying instinct and those which come within the sphere of reason, and in relation to which the insect must consider, compare, and judge. Yet this line, even in the light of his own work, is so extremely variable, needing readjustment with every new species and often among the individuals of the same species, that it loses for others the meaning which it has for its author. He himself speaks of certain individuals of the genus Sphex which refuse to be duped when he withdraws their prey to a distance. These, he says, are the élite, the strong–headed ones, which are able to recognize the malice of the action and govern themselves accordingly, but these revolutionists, apt at progress, he goes on to say, are few in numbers. The others, the conservators of old usages and customs, are the majority, the crowd. Yes, but is it not always the strong–minded few that direct the destiny of a race?
THIS wasp (Sphex ichneumonea Linn.) is one of our most beautiful species, its great size and its brilliant color, as it flies among the flowers, serving to make it well known to all observers of nature. During the later part of July, all through August, and even in the early days of September it is commonly found at work making or storing its burrow. It is rare in our garden, however, and we thought ourselves fortunate in being able to keep track of one individual from the making to the closing of the nest. Although large and powerful it is gracefully formed. In color it is brown, varied with bright yellow.
On the morning of the third of August, at a little after ten o’clock, we saw one of these hunters start to dig a nest on the side of a stony hill. After making some progress in the work she flew off and selected a second place, where she dug so persistently that we felt confident that this was to be her final resting–place; but when the hole was two and one half inches deep, it too was deserted. Again our wasp chose a spot and began to burrow. She worked very rapidly, and at twenty minutes before twelve the hole was three inches deep. At high noon she flew away, and was gone forty minutes. The day was excessively hot, about 98° Fahr., and we ourselves were only deterred from taking a noonday rest by our fixed determination not to leave the place until we had seen all that there was to be seen in the manœuvres of ichneumonea. On returning she appeared very much excited, fairly quivering with vitality as she resumed her work. She came up backward, carrying the earth with her mouth and anterior legs, and went back from the opening some little distance, when it was dropped, and she at once went in again. While in the burrow we could hear her humming, just as the Pelopæi do when, head downward in the wet mud, they gather their loads for nest–building. In five or six trips a little mass of earth would accumulate, and then she would lie quite flat on the heap and kick the particles away in all directions. As the work progressed the earth was carried further and further away before it was placed on the ground, and as she backed in different directions the material brought out was well spread about from the down–hill side of the nest. Sometimes she would spend several moments in smoothing the débris all around, so that the opening presented much the appearance of an immense ant–hill, only the particles were much larger. During the first hour that we watched her she frequently turned directly toward us, and, sometimes remaining on the ground and sometimes rising on her wings to a level with our faces, appeared to be eyeing us intently for four or five seconds. Her attitude was comical, and she seemed to be saying, “Well, what are you hanging around here for?”