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True Bees — Part 8

It was in their study of one of the Ammophilas that the Peckhams noticed a very distinct personality among the females which they watched at work. This personality was not of individual appearance but of such mental attributes as careful painstaking or carelessness and industry or laziness. One seemed to hurry tremendously and spent no time on non-essentials. Another was an artist, working for a long time on the closing of her burrow, arranging the surface with scrupulous care and sweeping away every particle of dust to a distance. Still another went to the extreme in carelessness, carrying the caterpillar in a very careless way and making a nest which was a very poor affair. Still a fourth was "the most fastidious and perfect little worker of the whole season, so nice was she in her adaptation of means to ends, so busy and contented in her labor of love, and so pretty in her pride of her completed work." In fact, they seem to have almost as much individuality as human beings and the result of these observations has a strong bearing on the discussion of instinct. Fabre, the French entomologist, who studied the same insects, considered that they were inspired by automatically perfect instincts which can never have varied to any appreciable extent from the beginning of time. Deviation from the regular rule, he thought, would mean extinction. The Milwaukee authorities, however, found that variability was the one unmistakable and ever present fact, and this variability existed in every particular, in the shape of the nest and in the manner of digging it, whether it is left closed or open, in the manner of stinging the prey and of crushing it, in the manner of carrying the victim, in the way of closing the nest and in the condition produced in the victim by the stinging, some dying and others living for a long time, though nearly motionless. All this variability the Peckhams got from the study of nine wasps and fifteen caterpillars!

The mud-daubers of the genus Sceliphron (formerly and in most books placed in the genus Pelopaeus) are among the most interesting members of this super-family. They build their nests of plain mud in sheltered places under the eaves of barns or even in the attics of houses. The food supply with which the cells are stored consists almost invariably of spiders, as many spiders being packed into one cell as the cell will hold. A single egg is laid upon the last spider packed in and the larva eats rapidly, consuming the abdomen of the spiders first and subsequently the rest of their bodies, eating both dead and living spiders. After the egg is laid and the nest closed up new cells are constructed by the same female.

A curious observation has been made by Schwarz in the Washington parks and gardens. He found that one of the Sphegid wasps--Chalybion coeruleum--was engaged in capturing a certain kind of spider which hid itself so carefully that it was most difficult to find. Instead of spending her time in fruitless searching the wasp would entangle herself in the web of the spider when the latter would immediately dart out from her hiding place, thus exposing herself to the wasp who would easily free herself from the web and chase the spider to its retreat.

Life History of a Digger Wasp

(Sphecius speciosus Say.)