Page:Popular Science Monthly Volume 57.djvu/35

From Wikisource
Jump to: navigation, search
This page has been validated.
25
A BUBBLE-BLOWING INSECT.

the early summer. These flecks of froth may be found very commonly at the junction of the leaf with the stem. Immersed in this froth is found a little green insect, sometimes two or three of them, concealed by the same moist covering.

PSM V57 D035 Grass stalk and leaves showing the appearance of froth.png
Fig. 1.—Grass stalk and leaves, showing appearance of froth.

This little creature represents the early stage of an insect which in its full growth still lives upon grass, and is easily recognized by its triangular shape and its ability of jumping like a grasshopper. There are a number of species; the one living on grass apparently confines itself to the grass alone, though I have seen one species that frequents a number of different plants. A species found on the white pine is dark brown in color, and the froth in which it is found not only hangs pendent from the branch, but the lower portion appears as a large drop of clear water.

Let one provide himself with a good hand lens, a bit of glass (a watch crystal is especially suitable for this purpose), and a common camel's hair brush, and he is ready to make a preliminary study of Aphrophora. The brush is convenient for easily removing the insect from the froth which invests it. If the insect is cleared from the mass of froth, it will crawl quite rapidly along the stem of the plant, stopping at times to pierce the stem for the purpose of sucking the juices within, and finally settling down in earnest, evidently exerting some force in thrusting its piercing apparatus through the outer layers, as shown by the firm way in which it clutches the stem with its legs. After sucking for some time, a clear fluid is seen to slowly exude from the posterior end of the abdomen, flowing over the body first and gradually filling up the spaces between the legs and the lower part of the body and the stem upon which it rests (Fig. 2). During all this time not a trace of an air bubble appears; simply a clear, slightly viscid fluid is exuded, and this is the only matter that escapes from the insect. In other words, its secretion of clear fluid is precisely like that of the Madagascar species referred to by Westwood and others.

This state of partial immersion continues for half an hour or more. During this time, and even when the insect is roaming up and down the grass or twig, the posterior segments of the abdomen are extended at intervals, the abdomen turning upward at the same time. It is a kind of reaching-up movement, but whether