REPORT OF THE STATE ENTOMOLOGIST I9II JI 



selves. Their strong forelegs are well adapted for digging and 

 are undoubtedly of great service in searching for the tender 

 succulent rootlets on which they feed. The Cicadas grow so 

 slowly and require so little food that but slight injury to trees 

 or shrubs appears to result from their presence. They remain 

 at moderate depths, especially during the ealier and latter por- 

 tions of their existence though at times they have been found 

 a number of feet below the surface. There is little change dur- 

 ing the subterranean existence, except in size, between the newly 

 hatched young and the full-grown nymph, which latter has on 

 the thorax four scalelike appendages, the rudimentary wings. 

 The insects make their way to the surface in the spring of the 

 seventeenth year through a smooth, firmly compacted gallery 

 which may even pierce the hard surface of a pathway or 

 roadside and under certain conditions may be covered with a cone- 

 like chamber made of mud pellets. 



Description. The periodical Cicada (plate 21, figure 6) may 

 be easily distinguished from the common dogday Cicada or 

 harvest fly, Cicada 1 i n n e i Grossb. by the eyes and veins 

 of the wings being bright red. More or less of the ventral 

 surface of the abdomen (especially in the male) and the legs 

 are dull red. The dorsal surface of the body is almost entirely 

 black. The periodical Cicada is more slender than the stouter 

 dogday Cicada, which latter has green markings on the thorax, 

 greenish eyes and bright green wing veins. 



Distribution. The Hudson valley brood is one of the best 

 known, since it occurs throughout a populous section. Aside 

 from the New York localities given in detail below, it has been 

 recorded from Connecticut, District of Columbia, Indiana, Mary- 

 land, Michigan, the entire state of New Jersey, North Carolina, 

 Pennsylvania, Virginia and West Virginia. An examination of 

 the map indicating the distribution of this brood, shows that it 

 is largely confined to the eastern slope of the Appalachian 

 mountains, the few records in the central states apparently 

 being isolated colonies. There are authentic records of the 

 appearance of this brood extending back to 1724. 



Comparative abundance. It is difficult to give any very 

 exact data respecting the comparative abundance of an insect 

 appearing only once in seventeen years, nevertheless the follow- 

 ing observations indicate an apparent increase in some localities 

 with a reduction in others, compared with the brood appearing 

 in 1894. The Cicadas 'were about the same at Copake Falls 



