124 MISC. PUBLICATION 657, U. S. DEPT. OF AGRICULTURE 
that of the well-known periodical cicada occupies 17 years (Davis, 
127). 
The periodical or 17-year cicadas (Magicicada septendecim (I.) 
and MW. cassinti (Fish.)), one or the other of which occurs from New 
England west to Iowa and south to Florida and Texas, are about 114 
inches long from the tip of the head to the tip of the folded wings. 
The eyes and legs are red. In the female the dorsum of the abdomen 
18 black, and the sides and ventral surface are banded with orange 
brown. In the male the dorsal surface of four or five of the ab- 
dominal segments is orange brown, rather than black, as in the 
female, and there is a pair of orange-colored covers to the sound- 
producing membranes beneath the bases of the wings. 
The female makes slits in the twigs of various trees and shrubs 
where she places her eggs late in the spring or early in the summer (fig. 
22). These eggs hatch in 6 to 8 weeks and the young nymphs drop 
to the ground, burrow into it, and attach themselves to the roots of 
plants by inserting their beaks. Here in small moist chambers they 
remain, feeding and growing, until time to emerge as adults (Marlatt, 
290) . 
The periodical cicada has two races in the United States. One 
race ranges from New England west to Iowa and central Kansas, 
and south to Georgia, and requires 17 years for full dev elopment. 
The other race ranges from Virginia west to Missouri and eastern 
Texas, and south to . Florida, and requires only 13 years to complete 
its development. Different broods of the two races emerge in differ- 
ent years in various places, and this results in the emergence of one 
or more broods every year in one place or another throughout the 
range of the species. 
Artificial control measures against this species have not been con- 
sidered practical, since to be effective contact insecticides would need 
to be apphed constantly during the period of adult emergence. How- 
ever, such extreme methods might be practicable in nurseries, where 
damage to seedlings by the ovipositing females is sometimes rather 
severe. 
FamMity PSYLLIDAE 
These are rather small insects, from 2 to 5 mm. long. The hind 
legs are formed for jumping, and the adults of both sexes are 
winged. When examined under magnification, the adult insects bear 
a striking resemblance to the enormously larger cicadas. They are 
very active, jumping and flying when disturbed. 
Forest and shade trees are attacked by several species in this 
group of insects. Hackberry is the host of four gall-producing species 
in the genus Pachypsylla. These are P. celtidis- -gemma Riley, P. cel- 
tidis-mamma (Fletcher), P. celtidis-vesicula Crawf., and P. ven- 
usta (Osten-Sacken) (fig. 23), all of which cause ealls on leaves or 
leaf petioles. In the genus Psyl/a, the nymphs of Psylla annulata 
Fitch feed on paper birch and maple, P. carpinicola Crawf. on birch, 
P. floccosa Patch on alder, P. galeaformis Patch on alder, P. nequn- 
dinis Mally on boxelder, P. st¢rata Patch on birch, and P. trimaculata 
Crawf. on wild cherry. Members of the genus Psy//a produce quanti- 
ties of honeydew on their hosts, giving them an unhealthy appearance 
because of the black mold that grows in the honeydew. For control 
of these insects, use a delayed dormant spray, followed by a contact 
insecticide, such as nicotine sulfate. 
