IOWA ACADEMY OF SCIENCES. 103 



ing jar conditions would be between three and four weeks. The bulk of the sec- 

 ond generation disappeared about the middle of August, and if an incubation 

 period of four weeks be accepted as something near an average, the larvie of the 

 third brood should have appeared shortly before the middle of September and 

 would mature about the middle of October. That the mature brood appears 

 before this calculated date, we have noted both in 1891 and in 1892, though we 

 have no record as to the time when the larvte appeared. 



DehocfphnJuf! iniitikufi Say had very nearly reached its maximum and was well 

 gone by the end ot the month. The larv;e of the second brood were very conspicu- 

 ous during the early part of August and were maturing in the latter part of the 

 month and early September. As an adult brood is known to be present about the 

 middle of October it seems that there must be three broods of this insect also. D. 

 inimicus seems to differ from debilis in its life history only in being about two weeks 

 later in maturing its respective broods. It is possible that some of the very latest 

 individuals of debilis represent a fourth brood as a few scattering specimens may 

 be taken as late if not later than inimicus. 



These insects have such a vastly important economic relation that some practi- 

 cal deductions from these studies will, I trust, not be considered out of place here. 

 I have in earlier publications called attention to^burning as a means of preventing 

 the increase of these pests and some observations that showed advantage where 

 this was practiced. Now that it is determined that the eggs of the most destruc- 

 tive species of the grass leaf-hoppers are deposited in the olades of grass during 

 late autumn it is evident that there is a substantial basis for practical results from 

 burning either in late fall or early spring and wlaere the old growth of grass is too 

 short to allow of ready burnmg it may be excellent policy to spread a thin layer of 

 straw to assist the spread of flames or even to take stock from pasture early 

 enough in fall to permit a growth of grass that will burn readily the following 

 spring. 



ADDITIONS AND CORRECTIONS TO CATALOGUE OF HEMIPTERA. 



HERBERT OSBORN. 



I desire here to make a few additions and corrections to the list of Hemiptera 

 presented in last report. 



Aiiasa tristis, DeG. The common squash bug reads Batmsa tristis, and as 

 there is a genus Banasa in a preceding family the correction is important. 



The family Beri/tidd' is made to include the species of Corizxs and Leptncorisa, 

 but should include only Jahjsus spinosus, Say. This ariangement follows Uhlers 

 Check list, but there the sub family Rhopaliua is made to include Corizus, etc., all 

 these being included with CoreiiUe in the super family Coreoidea. It would prob- 

 ably better the arrangement and still preserve the super family and the sub family 



