February, '22] hadley: Japanese beetle 65 



That phase of the biological work having to do with the importation 

 and colonization of natural parasites has progressed fully as satis- 

 factorily as was anticipated. Two species of parasites have been 

 received from Japan in quantities siifficient to possibly permit natural 

 colonization another season, providing the material on hand success- 

 fully survives the coming winter. One predaceous species received in 

 considerable nimibers this year from Japan has demonstrated its ability so 

 far to survive conditions obtaining in the Riverton district and this species 

 will possibly also be colonized the coming season. Reports from our 

 men in Japan indicate that they will be able to supply us with large 

 numbers of at least one and possibly two more parasitic species during 

 the coming season. 



Am.ong the native species parasitic upon related insects, it has been 

 learned that some may to a greater or lesser extent, attack the Japanese 

 beetle. Several species of white grub parasites were successfully brought 

 in considerable numbers last spring from Illinois and apparently are 

 suited to conditions existing in the Riverton district, and it is believed 

 that some of them may in time becom.e a factor in the natural control 

 of the Japanese beetle. 



Grub Insecticide Investigations 



Satisfactory progress has been made in the study of methods of 

 attacking the insect in its larval stages. The fact that the larvae may 

 become a serious menace to lawns, golf courses and other favorable 

 situations, as reported by Mr. Smith, emphasizes the necessity for 

 continuing the investigations now imder way toward the finding of 

 satisfactory control measures to meet these conditions. 



Comprehensive experiments are also being conducted in an effort 

 to develop a means of freeing from infestation by the grub nursery 

 stock shipped with soil about the roots, such as the various conifers. 

 This is one of the most important ways by which the insect may be 

 distributed long distances, by reason of the fact that it is impossible 

 to satisfactorily inspect such stock without removal of the soil. 



Beetle Insecticide Investigations 



Considerable progress has been made in the work looking toward the 

 development of satisfactory methods of killing the beetle by means of 

 sprays. A paper presented at this meeting by Messrs. Leach and Brinley 

 of the Japanese Beetle Laboratory reports the use of soap solutions as 

 contact sprays against the beetle. The best results were obtained 

 with the use of a sodium soy bean soap, and under certain conditions a 

 contact spray of this material gives very satisfactory results. 



