Page:Insects - Their Ways and Means of Living.djvu/73

 squeaking note resembling shriek with the s much aspirated and with a prolonged vibration on the ie. The next evening he played again, making at first a weak swish, swish, swish, with the s very sibilant and the i very vibratory. But after giving this as a prelude he began a shrill shrie-e-e-e-k, shrie-e-e-e-k, repeated six times, a loud sound described by Blatchley as a "creaking squawk—like the noise made by drawing a fine-toothed comb over a taut string."

The best-known members of the round-headed katydids, and perhaps of the whole family, are the angular-winged katydids (Fig. 23). These are large, maple-leaf green insects, much flattened from side to side, with the leaflike wings folded high over the back and abruptly bent on their upper margins, giving the creatures the humpbacked appearance from which they get their name of angular-winged katydids. The sloping surface of the back in front of the hump makes a large fiat triangle, plain in the female, but in the male corrugated and roughened by the veins of the musical apparatus.

There are two species of the angular-winged katydids in the United States, both belonging to the genus Microcentrum, one distinguished as the larger angular-winged katydid, M. rhombifolium, and the other as the smaller angular-winged katydid, M. retinerve. The females of the larger species (Fig. 23), which is the more common one, reach a length of 2⅜ inches measured to the tips of the wings. They lay flat, oral eggs, stuck in rows overlapping like scales along the surface of some twig or on the edge of a leaf.

The angular-winged katydids are attracted to lights and may frequently be round on warm summer nights in the shrubbery about the house, or even on the porch and the screen doors. Members of the larger species usually make their presence known by their sort but high-pitched notes resembling tzeet uttered in short series, the first notes repeated rapidly, the others successively more slowly as the