April, 16] DAVIS: WHITE GRUB INVESTIGATIONS 269 



do not normally make their appearance until late June, occurring 

 throughout the month of July and into August. From these notes it 

 will be noticed that certain species are active above ground two months 

 or more, while others disappear after three or four weeks. The longer 

 period of existence is due to a longer period of life, and not to a suc- 

 cession of beetles, for in our cages where individual pairs were confined 

 the length of life of the beetles coincided with the occurrence of the 

 same species out-of-doors. 



It is interesting to note the predominant species in different local- 

 ities where grubs are of considerable economic importance. In the 

 west — Utah, Idaho and Montana — the Lachnosternas are beginning to 

 make their appearance as pests of importance and here the species 

 involved is L. dubia. In the southeastern corner of South Dakota, 

 the grubs have become very serious pests and here L. vehemens pre- 

 dominates. In northeastern Iowa, southwestern Wisconsin and north- 

 western Illinois, a center of a very heavy infestation and in an ungla- 

 ciated region, we have L. fusca as the predominant species. L. rugosa 

 is the dominant species in south central Wisconsin, being confined to 

 the glaciated portion of the state, while a little farther to the east, in 

 the vicinity of Beaver Dam, L. fusca again becomes the prevalent one. 

 In the state forest nurseries of Minnesota and Wisconsin, the former 

 at Lake Itasca and the latter at the extreme north border of Wisconsin 

 in Vilas County, considerable trouble has been experienced with white 

 grubs and at both of these places L. grandis is the predominant species. 

 In the southwestern part of Michigan in and about Kalamazoo County 

 the 1914 brood was a destructive one and here the predominant species 

 is L. hirticula although fusca is also a common species. South and 

 east of this infested district, that is, south of Battle Creek, we have 

 another occurrence of hirticula but of a different brood, the date for 

 the next flight of beetles in this district being 1916. In the "thumb 

 district" of Michigan and on south into Ohio the 1914 brood was very 

 important and it is interesting to note that here again in the glaciated 

 area L. rugosa is decidedly the predominant species, but going a little 

 east into Ohio the species doing the damage are hirticula and fusca, the 

 former being the more common, according to our observations, in the 

 center of the infested area. Continuing eastward into Maryland, 

 hirtictda again appears as the important species while in the infested 

 counties of New York dubia and fusca are the two common ones. 

 Going south we find congrua and crassissima are injurious species in 

 Missouri while in Kansas wheat is attacked by white grubs mostly of 

 the species lanceolata and crassissima. In the central part of Texas 

 (Travis County), a great deal of damage to corn, cotton, and grass- 

 lands by grubs of L. torta has been reported. 



