266 MAINE: AGRICULTURAL EXPERIMENT STATION. 1916. 



dition. This condition persists even during rather heavy rains, 

 showing a certain insolubility in water as well as in alcohol. 

 The glands from which the secretion comes are located laterally 

 in the abdominal segments (the 7th and 8th) and in a specimen 

 of one of the intermediate instars, probably the third, they 

 appear as black spots. In other instars, so far as observed, 

 they are not specially colored but show in mounted specimens 

 as a more opaque area while the surface is roughened over a 

 triangular area though no gland openings have been observed 

 in the material studied. The pores may be too minute for 

 ready observation. A similar secretion has been observed for 

 Clastoptera. 



The purpose of the frothy masses is generally assumed to 

 be for the protection of the nymph and it is easy to see that 

 they are pretty well guarded against many of the smaller kinds 

 of enemies such as spiders and other arthropods. Some dis- 

 tinct adaptations associated with the habit are to be noted as 

 for instance, the loss in large degree by the nymphs of the 

 leaping habit and also the nearly complete loss of color. 



That these two species have a distinct preference, if not a 

 positive restriction to particular food plants is indicated by the 

 fact that spumarius is taken almost entirely from plants other 

 than grasses while lineatus is taken almost exclusively from 

 grasses, especially timothy and redtop. 



As a test of their choice in this matter on July 9th ten indi- 

 viduals of lineatus were transferred from timothy to clover 

 and of these none lived, though two had succeeded in changing 

 to adult stage probably being very near maturity. In the reverse 

 test ten specimens of spumarius were transferred from clover 

 to timothy and only two lived to become adults, none made 

 froth on the timothy and all showed restlessness and attempts 

 to move. They evidently failed to secure sap and it is possible 

 that there is some distinct difference in the mouth parts cor- 

 related with the different food plants as well as a difference in 

 selection. 



The economic importance of these species has been variously 

 estimated though I think too generally overlooked. I find in 

 an early record in the Maine Farmer for July 26, 1866, the 

 following note by G. E. Brackett under the head of "Practical 

 Entomology :" 



