168 Bugs, Cicadas, Aphids, and Scale-insects 
they cut with the sharp ovipositor in the twigs of various trees, in this way 
often doing much damage to orchards and nurseries. The young hatch 
in about six weeks and drop to the ground, where they burrow down through 
cracks and begin their long underground life. They feed on the humus 
in the soil and, to some extent, on juices sucked from the tree-roots. They 
grow slowly, moulting probably four or six times at intervals of from 
two years to four years. In spring or early summer of the seventeenth 
year (thirteenth in a race in the southern states) they come above ground, 
and, after hiding for a while under stones and sticks, crawl up on the trunks 
of trees and there moult for the last time, the winged adult emerging and 
soon flying into the tree-tops. The various broods or swarms in this country, 
about twenty in number, are known, and the territory occupied by each 
has been mapped, so that it is possible for entomologists to predict the 
appearance of a swarm of seventeen-year cicadas in a particular locality 
at a particular time. As all the members of one of these swarms issue in 
the same season, and indeed in the same month or fortnight, they usually 
attract much attention. The broods to issue in the next few years are the 
following: a large one in 1905 in the northern half of Illinois, eastern part 
of Iowa, southern part of Wisconsin, southern edge of Michigan, and northern 
and western edge of Indiana; a scattered one in 1906 ranging, not contin¬ 
uously, from Massachusetts south and west through Long Island, New 
Jersey, Pennsylvania, Maryland, West Virginia, Ohio, Indiana, Kentucky, 
Tennessee, North and South Carolina, and northern Georgia; and a large 
one in 1907, ranging from central Illinois south and east to the Gulf and 
Atlantic. 
A considerable number of small insects, often seed-like in shape, or 
with the thorax prolonged into odd horns, spines, or crests, are included 
in the families of tree-hoppers (Membracidae) and lantern-flies (Fulgoridae) 
(Fig. 237). Striking members, large and bright- 
colored, of this latter family are found in the 
South American tropics, but the North American 
species are small, and are rarely seen or collected 
by amateurs. Among the commonest of our forms 
are the candle-heads, species of Scolops, small 
insects living on grass and herbage, with the head 
bearing a long slender upcurving projection. The tree-hoppers (Mem- 
bracidae) almost all suggest small angular brownish seeds or thorns in shape 
and color. The prothorax is sometimes widely expanded, sometimes 
lengthened so as to cover nearly the whole body, sometimes humped or 
crested, sometimes spined or pitted. The unusual form is probably pro¬ 
tective, making the insects simulate seeds or other plant structures. The 
species of Enchenopa (Fig. 239) are curiously horned. E. binotata is common 
Fig. 237.—A fulgorid, Stobera 
tricarinata. (After Forbes; 
natural length j inch.) 
