526 The University Science Bulletin. 



(Buus lineatus (Linn.), states that during nymphal life the bug may 

 construct several balls, but that there usually is little migration 

 after the first mass is formed. Kershaw (1914) , on the other hand, 

 is of the opinion that the nymphs of Tomaspis saccharina usually, 

 but not always, leave the spittle mass after a molt. 



In the study of Lepyronia quadrangularis an experiment was at- 

 tempted to determine just to what extent these migrations were car- 

 ried on in the field. Four goldenrod plants bearing spittle masses 

 were marked with white rags about May 12. It was difficult to de- 

 termine in what stage the nymphs were at this time, since it was not 

 thought best to disturb them, but they appeared to be in the latter 

 part of the first stage. On May 16 three plants had second instars 

 on them and the fourth had a second- and a fourth-stage nymph in 

 one mass. On May 27 these plants were observed again. One plant 

 was entirely deserted, but the other three appeared to be all right, 

 with the spittle masses in practically the same position. June 2 

 found them practically the same, but other weeds were beginning 

 to crowd around them so that little data thenceforth could be ob- 

 tained. On June 7, however, one or two new masses of spittle were 

 found on each of the marked plants, including the deserted one, 

 which now bore three masses. This seems to point to the conclusion 

 that the nymphs do move in the field even when not disturbed. Fre- 

 quently, while collecting, molted skins can be found in deserted 



spittle masses. 



In captivity, at least, as was stated above, the nymphs move con- 

 siderably. Following the records of a few reared from first instars 

 to adults may illustrate this fact. One first instar collected on May 

 6 was placed on a plant and soon formed a spittle mass. On May 

 17 it molted to a second instar, remaining in the same mass of spit- 

 tle until May 18. On this date it moved farther down on the plant 

 and made a new mass. It remained in this mass of spittle until 

 June 7, in the meantime having molted on May 23 and May 25. 

 After this last migration it formed a new mass of spittle higher up 

 on the plant, where it remained until emerging as an adult. Another 

 nymph, collected on May 12 and reared to adult, moved only twice, 

 both times being between molts and not just after. Still another 

 moved three times during its five changes. A fourth specimen, col- 

 lected in the second stage, moved six times before emerging as an 

 adult, and only once moved directly after molting. From the fore- 

 going there appears to be no fixed habit of moving after each molt. 



