Doering: Lepyronia quadrangularis. 525 



usually necessary to shove the insect around in the spittle mass in 

 order to see the skin, and this often disturbed the nymph so much 

 that it would immediately hunt a new place. 



Lepyronia nymphs have a comical appearance while walking over 

 the plant. Their legs are long and they walk with their bodies lifted 

 high in the air. Sometimes they walk exceedingly fast, but at other 

 times they merely creep along. Occasionally the nymph extends 

 its abdomen in the air at right angles to its body, first expanding it 

 and then contracting it in a telescopic manner; it does this even 

 while it walks. 



The gregariousness of spittle insects is pkinly evident, although 

 it probably is due more to chance than instinct. A probable ex- 

 planation is that in their roaming over the plants they encounter 

 other spittle masses, and it is much easier to stay in this than to 

 make a new mass. In many cases three or four instars have been 

 found together in the same spittle mass. For this reason, toward 

 the last of the season the first instars are not so readily seen unless 

 each spittle mass is examined, since they are found deeply imbedded 

 in the spittle mass made by larger nymphs. On one stalk of Ambro- 

 sia trifida (horseweed) three inches of solid spittle were found ex- 

 tending all around the stem. In the mass there were thirty-one in- 

 sects, of which sixteen were fourth instars, ten were third instars, 

 and five 'were fifth instars. Fifteen molted skins were found in it 

 also. On another plant were found three large masses of fourth and 

 fifth instars, which were packed so closely together that the spittle 

 scarcely covered them. Spittle masses were very large and abun- 

 dant on elm sprouts; one stalk bore a mass of spittle which extended 

 four inches along the stem ; another branch bore eleven masses. On 

 another host plant two large masses of spittle were found, one mass 

 containing six nymphs and the other six or ten. On June 13, on a 

 single plant of Ambrosia trifida a spittle mass twelve inches long 

 was found, which contained sixty-eight or more nymphs. The spit- 

 tle was white and foamy, but was barely enough to cover the 

 nymphs, since the form of their bodies could be plainly seen 

 through it. 



In the literature ii is often stated that the nymph lives and molts 

 in the same mass of spittle until the adult form is reached. Com- 

 stock (1895), in his brief discussion of Cercopidae, states that it had 

 been asserted that they undergo all their changes in the spittle mass, 

 Girault (1904) says of Aphrophora parallela (Say), that they seldom 

 move unless disturbed, and Garman (1921), in his work with Phil- 



