ENTOMOLOGY. 153 



more thau a starting point for future work. Some of the results which seem to he 

 general in nature may he mentioned here. 



"The species of Jassida? have as a rule a decided limitation as to food plants, usu- 

 ally holding closely to one species of plant, almost invariably limited to one plant for 

 breeding, hut feeding more indiscriminately in maturer stages. 



"So far as known all the species deposit eggs upon the stems under the leaf 

 sheaths or in the leaves of the plants used as food. 



"There is a wide difference in life histories, some having one brood, the majority 

 of the grass-feeding species two, and still others three in a season, and the suc- 

 cessive stages occurring at widely different times. 



"Except in the case of adult hibernation the ordinary life of a brood of adults 

 does not exceed two months, and for the individuals of a brood rarely over one. 

 The males appear a week or ten days before the females and disappear as much 

 earlier. In general, one brood of adults will have disappeared before the larvae of 

 the next have matured, so that individuals collected at any time may be referred 

 with assurance to a particular brood. 



"It follows also that eggs for each brood are deposited within a limited time and 

 that a period may he defined during which all ejjgs of a given brood lor a given 

 species will have been deposited and during which measures for their destruction 

 may be applied. 



"( Observations were made to ascertain whether simply cutting the grass and leav- 

 ing it in the field would prevent hatching, and in no case, were eggs observed to hatch 

 from the stems cut green. Part of the stems from a plant in which eggs were fully 

 developed were cut and left to dry. The second day after the eggs hatched m the 

 uncut stems, but no larvae issued from those that were cut. and on examination the 

 eggs were found to he crushed and distorted from the shrinking of the plant tissues 

 and by the curling of the edges of tins sheaths in drying. Even if hatched they 

 would have been unable to escape from the rigid incurved edge." 



The method of study was largely that of rearing in blooding cages 

 made of glass globes or netted frames over grass in large plats together 

 with continuous field study. Many thousands of individuals in all 

 stages were examined. Some CO species were noted as grass feeders. 



Some of these, like Diedrocephala coccinca, Xerophlcea viridis, Gypona 

 octolineata, Parabalocratus viridis, Platymetopius cinerous, Deltoceph- 

 alus sayi, D.configuratus, I), alb id us, etc., are noted as donble-brooded. 

 Further, some are shown to exhibit the phenomena of seasonal dimor- 

 phism, and the Gypona fiavilineata of Fitch is shown to be nothing more 

 thau the first brood form of G. octolineata. 



Several of the species, as for example Deltoeephalns oculatus and 

 AtJiysanus obtains and A. bieolor are partial to .1 ndropogon scoparius. 



Most of the species are described and the adults and larvae together 

 with many of their structural details figured in the plates. 



Other species noted are Diedrocephala mollipes, D. novceboracensis, 

 the eight-lined gypona (Gypona octolineata), Eitacanthus acuminatus, 

 shovel nose leaf hopper (Borycephalus platyrhynchus), spoon bill leaf 

 hopper (Heealus lineatus), Deltocephalus debilis, D. inimicus, 1>. mel&liei- 

 meri, J>. inflatus, 1). reflexus, D. pectinatus, D. abbreviates, D. compactus, 

 I>. signatifrons, I), weedi, D. sylvestris, D. ouclatus, D. minimus, AtJiy- 

 sanus eurtisii, A. bieolor, A. obtutus. 



The San Jose scale in Illinois, S. A. Forbes (Illinois Sta. Bui. 

 48, pp. 413-428, figs. 2). — This bulletin is based upon a paper read by the 



