Distribution o] 

 eastern "locust" 

 broods 



Brood II _l-\ _i 

 Appeared 1911 [/ ( I i u 



Due againl928 _ ^^" ' ' '" 



Brood VI 

 Due 1915 and 

 again in 1932 



Brood VIII 



Due 1917 



and 1934 



animals immediately drop to the ground and 

 burrow into the soil to dwell in darkness until 

 that subtle influence called instinct calls them 

 into the outer world. 



But ere these little fellows have broken 

 through the eggshell the weight of the branch 

 beyond the point at which the eggs were laid, 

 aided by the wind, may have caused the twig 

 to break, and the leaves beyond the break may 

 then turn brown. The injury to a large tree, 

 aside from the unsightly appearance of the 

 dead leaves, is slight and the tree soon recovers 

 completely; but small trees, especially seed- 

 lings are often killed. All in all, little appre- 

 hension need be entertained by the farmer or 

 fruit-grower as a locust year approaches, for 

 at most he must needs only forbear to plant 

 young trees that year; and to the lo^'er of the 

 curious in nature a locust year is one looked 

 forward to with great interest. 



In the group now installed on the third 

 floor the insects are shown emerging from the 

 ground through neat circular openings on a 

 level witfe the surface where the soil is compact 

 and bare of vegetation, and through the tops 

 of mud towers or "cones" which the young 

 cicadas have constructed where the soil is 

 moist, particularly where there is a layer of 

 leaves or grass. On the trunk of a sweet gum 

 tree and on some of the leaves of the scrub 

 white oak nearby are munerous shed pupal 

 skins, and adults delicate and white are seen 

 breaking through the skins, or expanding their 

 wings after ha\ing just emerged. Fully col- 

 ored adults, blackish conspicuously marked 

 with red, are shown resting on the twigs, 

 some in the act of egg-laying. Certain of the 

 insects in tlu> group are represented as aft'ected 

 by the fungous disease known as Massopora 

 cicadina. Also egg puncturc^s are shown on 

 some of the twigs, and the result of these in 

 the broken twigs with dead leaves is con- 

 spicuous among the fresh sunnner foliage. 



An Knglish sparrow, that inveterate de- 

 strover of the cicadas among the many birds 



188 



