CICADA, si-ki.'da, a large insect of the order Hemiptera, sub-order Homoptera and family Cicadidce, known by its broad head, pro tuberant eyes, sucking beak and well-developed ovipositor. The male cicada makes a shrill noise by means of a special apparatus at the base of the abdomen or hind-body. The males only possess this sound-organ. "Happy,* said Xenarchus, "are the cicadas' lives, for they all have voiceless wives" The loud, piercing notes issue from a pair of structures or cavities on the under side of the body, which act some what as two kettle-drums or 'timbals,* each cav ity being covered by a tense membrane which is rapidly vibrated by means of two special mus cles within. The sound is variously modified by adjacent smaller disc-like soundinrboards, which increase and transmit the sound vibra tions caused by the movement of the membrane. The sound is modified by the semi-circular discs, one on each side projecting from the metathorax over the "mirrors," cover-plates or sounding boards, one on each side and which, when closed, deaden the sound, or, if open, allow it to escape in greater volume. This apparatus appears to be homologous with the •ears* of the locusts or common grasshoppers. Cicada have an incomplete metamorphosis, the young (nymphs) being like the parents, but without wings; they live attached by their beaks to the roots of trees, etc. The female deposits her long, slender, cylindrical eggs in gashes in twigs made by her saw-like ovipositor. From 400 to 600 eggs are laid, the process requiring about 45 minutes. The two commonest forms in the United States are the dogday harvest fly (C. tibicen) and the periodical cicada (C. septen deceits). The former is the black-and-green harvest fly which• appears in midsummer and gives out its shrill notes during the heat of the day from the tree tops. It matures in two years, but there being two broods, one appears every year. The 17-year cicada (wrongly called 17-year locust) is the longest-lived of any known insect, as the grub or nymph lives for over 16 years sucking the. roots of forest trees,
often several feet below the surface; in the late spring it finishes its transformations and usually at the last of May or the beginning of June issues in enormous numbers from the round. This appearance of a 17-year brood in a given area has been recorded as far back as 1633. At the present time each year has its brood or broods, each limited, as a rule, to a well-defined district. Of such broods there are 30, occurring over a large area in the Atlantic and Central. States. In southern New England a broad periodically appears near Fall River and on Martha's Vineyard, as well as in Connecticut, while in Rhode Island its first appearance known in history was in the first week in June 1903, in the town of Coventry, near Tioguc reservoir. The southern limits are northern Georgia and the western limits are eastern Nebraska and Kansas. Besides this 17 year brood is a 13-year brood, which is more southern, the dividing line being about latitude 38° ; this appears to temperate variety. The male is very short-lived and takes no food. The females live for several weeks and de posit their eggs about the middle of June in New York and West Virginia. The young hatch, dropping to the ground about six weeks after the eggs are laid; they then burrow into the soil and begin to pierce the rootlets of trees. The nymph molts about once a year or oftener and Riley estimates the number of molts at from 25 to 30, while there are six stages of growth before the imago or winged state is assumed. Consult Riley, The Periodical Cicada) ((Bulletin 8 United States Department of Agri culture)); Marlatt, C. L., The Periodical Cicada' (ib. 14, Washington 1898), and Wood worth, (Synopsis North American Cicadidz' (in Psyche, Vol. V, Cambridge, Mass., 1888).