ANY wasps are not so waspish after all when we understand one important fact about them; i. e., although they are very nervous themselves, they detest that quality in others. For years the yellow-jackets have shared with us our meals at our summer camp on the lake shore. They make inquisitive tours of inspection over the viands on the table, often seeming to include ourselves, and coming so near that they fan our faces with their wings. They usually end by selecting the sweetened fruits, but they also carry off bits of roast beef, pouncing down upon the meat platter and seizing a tidbit as a hawk does a chicken. We always remain calm during these visitations, for we know that unless we inadvertently pinch one, we shall not be harmed; and it is great fun to watch one of these graceful creatures poising daintily on the side of the dish lapping up the fruit juice as a cat does milk, the slender, yellow-banded abdomen palpitating as she breathes. Occasionally, two desire the same place, and a wrestling match ensues which is fierce while it lasts, but the participants always come back to the dish unharmed. They are extra polite in their manners, for after one has delved eagerly into the fruit syrup, she proceeds to clean her front feet by passing them through her jaws, which is a wasp way of using a finger bowl.
Both yellow-jackets and the white-faced black-hornets build in trees and similarly, although the paper made by the yellow-jackets is finer in texture. However, some species of yellow-jackets build their nests in the ground, but of similar form. The nest is of paper made of bits of wood which the wasps pull off with their jaws from weather-worn fences or boards. This wood is reduced to a pulp by saliva which is secreted from the wasp's mouth, and is laid on in little layers which can be easily seen by examining the outside of the nest. These layers may be of different colors. A wasp will come with her load of paper pulp, and using her jaws and front feet for tools she will join a strip to the edge of the paper and pat it into shape. The paper tears more readily along the lines of the joining, than across. The cover of the nest is made of many layers of shell-like pieces fastened together and the outer layers are waterproof; the opening of a nest is at the bottom. Mr. Lubbock has shown that certain wasps are stationed at the door, as sentinels, to give warning on the approach of the enemy. The number of stories of combs in a nest depends upon the age and size of the colony. They are fastened together firmly near the center, by a central core or axis of very strong, firm paper, which at the top is attached to a branch or whatever supports the nest. The cells all open downward, in this respect differing from those of the honey-bee, which are usually placed horizontal. The wasp-comb differs from the honey-comb in that it is made of paper instead of wax, and that the rows of cells are single instead of double. The cells in the wasp-comb are not for storing honey, but are simply the cradles for the young wasps. (See Fig. p. 457.)
Sometimes a wasp family disaster makes it possible for us to examine one of these nests with its inmates. Here we find in some of the cells, the long white eggs fastened to the very bottom of the cell, in an inner angle, as if a larva when hatched needed to have a cozy corner. These wasp larvæ are the chubbiest little grubs imaginable and are very soft bodied. It was once a mystery to me how they were able to hang in the cells, head down, without getting "black in the face" or falling out; but this was made plain by studying the little disk at the rear end of the larva's body, which is decidedly sticky; after a larva is dead, its heavy body can be lifted by pressing a match against this disk; thus it evidently suffices to keep the baby wasp stuck fast to its cradle. The larva's body is mostly covered with a white, papery, soft skeleton skin; the head is yellowish and highly polished, looking like a drop of honey. At one side may be seen a pair of toothed jaws, showing that it is able to take and chew any food brought by the nurses. They seem to be well trained youngsters for they all face toward the center of the nest, so that a nurse, when feeding them, can move from one to another without having to pass to the other side of the cell. It is a funny sight to behold a combful of well grown larvæ, each fitting in its cell like meal in a bag and with head and several segments projecting out as if the bag were overflowing. It behooves the wasp larva to get its head as far out of the cell as possible, so that it will not be overlooked by the nurses; the little ones do this by holding themselves at the angle of the cell; this they accomplish by wedging the back into the corner. These young larvæ do not face inwards like the older ones, but they rest in an inner angle of the cell.
After a larva has reached the limit of its cell room, it spins a veil around itself and fastens it at the sides, so that it forms a lining to the upper part of the cell and makes a bag over the "head and shoulders" of the insect. This cocoon is very tough, and beneath its loose dome the larva skin is shed; the pupa takes on a decidedly waspish form, except that the color is all black; the legs and the wings are folded piously down the breast and the antennæ lie meekly each side of the face, with the "hands" folded outside of them; the strong toothed jaws are ready, so that when the pupa skin is molted, the insect can cut its silken curtain, and come out into its little nest world, as a full-fledged yellow-jacket.
What a harlequin the wasp is, in her costume of yellow and black! Often in the invertebrate world these colors mean "sit up and take notice," and the wasp's costume is no exception. Whoever has had any experience in meddling with yellow-jackets, avoids acquaintance with all yellow and black insects. Yet we must confess that the lady wasp has good taste in dress. The yellow cross bands on her black skirt are scalloped, and, in fact, all her yellow is put on in a most chic manner; she, being slender, can well afford to dress in roundwise stripes, and she folds her wings prettily like a fan, and not over her back like the mud wasp, which would cover her decorations. There is a sensation coming to the one who, armed with a lens, looks a wasp in the face; she always does her hair pompadour, and the yellow is here put on with a most bizarre effect, in points and arabesques. Even her jaws are yellow with black borders and black notches. Her antennæ are velvety black, her legs are yellow, and her antennæ comb, on her wrist, is a real comb and quite ornate.
In the nest which we studied in late August, the queen cells were just being developed. They were placed in a story all by themselves, and they were a third larger than the cells of the workers. The queen of this nest was a most majestic wasp, fully twice as large as any of her subjects; her face was entirely black, and the yellow bands on her long abdomen were of quite a different pattern than those on the workers; her sting was not so long in proportion, but I must confess it looked efficient. In fact, a yellow-jacket's sting is a formidable looking spear when seen through a microscope, since it has on one side some backward projecting barbs, meant to hold it firm when driving home the thrust.
While wasps are fond of honey and other sweets, they are also fond of animal food and eat a great many insects, benefiting us greatly by destroying mosquitoes and flies. As no food is stored for their winter use, all wasps excepting the queens die of the cold. The queens crawl away to protected places and seem to be able to withstand the rigors of winter; each queen, in the spring, makes a little comb of a few cells, covering it with a thin layer of paper. She then lays eggs in these cells and gathers food for the young; but when these first members of the family, which are always workers, come to maturity, they take upon themselves the work of enlarging the nest and caring for the young. After that, the queen devotes her energies to laying eggs.
Wasps enlarge their houses by cutting away the paper from the inside of the covering, to give more room for building the combs wider; to compensate for this, they build additional layers on the outside of the nest. Thus it is, that every wasp's nest, however large, began as a little comb of a few cells and was enlarged to meet the needs of the rapidly growing family. Ordinarily the nest made one year is not used again.
Leading thought—The wasps were the original paper makers, using wood pulp for the purpose. Some species construct their houses of paper in the trees or bushes while others build in the ground.
Method—Take a deserted wasp-nest, the larger the better, with sharp scissors remove one side of the covering of the nest, leaving the combs exposed and follow with the questions and suggestions indicated. From this study of the nest encourage the children to observe more closely the wasps and their habits, which they can do in safety if they learn to move quietly while observing. (See Fig. page 457.)
1. Which kind of wasp do you think made this nest? Of what is the nest made? Where did the wasp get the material? How do the wasps make wood into paper?
2. What is the general shape of the nest? Is the nest well covered to protect it from rain? Where is the door where the wasps went in and out? Is the covering of the nest all of the same color? Do these differences in color give you any idea of how the wasps build the paper into the nest? Does the paper tear more easily one way than another? Is the covering of the nest solid or in layers?
3. How many combs or stories are there in the wasp house? How are they fastened together and how suspended?
4. Compare the combs of the wasp-nest with those of the honey-bee. How do they resemble each other and how differ? Do the cells open upward or downward? For what purpose are the combs in the wasp-nest used? Are all the cells of the same size? Do you know the reason for this difference in size?
5. How do the young wasp grubs manage to cling to the cells head downward? Are the cells lined with a different color and does this lining extend out over the opening in some cases? Is this lining of the cells made of paper also? Do you know how a young wasp looks and how the white lining of the cells is made?
6. Do you believe that some wasps of the colony are always posted as sentinels at the door to give warning if the colony is attacked?
7. Do wasps store food to sustain them during the winter? What happens to them during winter? Is the same nest used year after year?
8. Can you describe the beginning of this wasp-nest? When was it made? Tell the story of the wasp that made it. How large was the nest at first? How was the nest enlarged?
9. What is the food of wasps? How do these insects benefit us?
10. Write a story giving the life history of a wasp.
11. In the summer watch a yellow-jacket eat from a dish of sweetened fruit which you may place out of doors to coax her to come where you can carefully observe her. What are the colors of the yellow-jacket? Where is the yellow? How are the yellow bands made ornamental? How does she fold her wings? How many wings has she? What is the color of her legs? Describe her antennæ and eyes. How does she eat the fruit juice? Can you see the motion of her body when she breathes?