LIFE HISTORIES OF LEAFHOPPERS OF MAINE. 5/ 



is shown in the statistics for 191 3) where there should be a 

 crop of two and a half to three tons of good hay is a matter of 

 some concern to the grower. Or, if the field is used for pas- 

 turage, it is as evident that there is much less of forage for the 

 stock pastured on a given area. 



The numbers of the different species may vary from year to 

 year and I am quite sure that the abundance of certain of the 

 species may bear some relation to the length of time during 

 which the field may have been in grass. It appears that the 

 six-spotted leaf hopper is one of the first to invade a new field 

 since it produces several generations and is quite migratory in 

 habit. After this, for Maine, the Deltocephalus minki appears 

 to be one of the earliest to appear in open fields, later the frog- 

 hoppers and Acocephalus striatus come in abundance and one 

 of the latest, perhaps the least migratory, is the Acocephalus 

 albifrons which has been found living down in the ground 

 around the crowns of timothy. 



Hibernation in General. 



In order to determine the place of hibernation of such of 

 the species as might be present, cages were placed in timothy 

 meadows on Dr. Patch's farm. These cages, two eighteen 

 inches square and two one foot by four feet were set out in 

 early spring before insects had become active and before any 

 migration had been possible. They were crowded down close 

 to the surface of the ground but not below the surface of the 

 soil. While it would be possible for insects of some kinds at 

 least to burrow under the frames there would certainly be no 

 probability that any of the Jassids would, if they were to flv 

 into the field from adjacent fence rows or thickets, do this and 

 it is a fair assumption that species found living within the 

 cages on the grass had- hibernated in one stage or another on 

 the spot. The same assumption, while less certain for some 

 other kinds of insects, or for spiders, phalangids, etc., is a fair 

 one especially if the content of the cages agrees well in pro- 

 portion with the surrounding grassland. 



While the primary purpose of these cages was to determine 

 this fact of hibernation in the field, examination showed such 

 an interesting association of animals and one so fairly typical 



