80 



beets were planted in an orchard. August 16 the worms were pupating 

 rapidly, about an inch below the surface of the ground, though there 

 were many very young larvae still on the beets. September 10 the 

 moths were hatching in great numbers, and there were still scattering 

 caterpillars on the beets. As mature ova could not be found in the 

 female moths at this time, and no more larvae appeared, it seems 

 probable that the moths hibernate during winter. The sudden appear- 

 ance of this insect in such numbers is almost unaccountable. For 

 several years a few parties had been growing beets, in an experimental 

 way, about Grand Junction, but no caterpillars had ever been seen 

 before, so far as I was able to learn. Last year a sugar factory was 

 erected, and a large acreage of beets was grown for the first time in 

 that region. At Delta, a town 50 miles distant by rail, and at Mont- 

 rose, 70 miles distant, where beets were also grown, the caterpillars 

 appeared in considerable numbers, but were not so numerous as near 

 Grand Junction. The larva? were also sent me from Rockyf ord, where 

 they were common on experimental beets, but not numerous enough 

 to attract much attention.^ 



The Arkansas Valley forms a sort of thoroughfare through which 

 insect pests have come to Colorado from the East. It was here we 

 first found the strawberry' leaf -roller, Phoxopteris comptana^ which is 

 established as a serious pest on both slopes of the Rockies in limited 

 localities. The cucunil)er beetle, Dlahrotka vittata, is a recognized 

 pest upon melon vines about Rockyford, l)ut seems to have done no 

 special harm in other localities, and the melon louse, now generally 

 distributed over the State, seems to have reached us by the same 

 route. Other insect enemies deserve mention, but I refrain from 

 occupying more of your time. 



NOTES ON INSECTS OF ECONOMIC IMPORTANCE FOR 1900. 



By W. G. Johnson, College Park, Md. 



The apple aphis, Aphk mall Fab., has been unusually abundant on 

 apples this year. It was the first pest of any consequence that occa- 

 sioned much correspondence. Twigs entirely incrusted with eggs of 

 this species were frequently sent to the ofiice during the fall and 

 winter. The attack this spring was very general, especially in young 

 orchards. I also found the same insect very common upon Kiefi'er 

 pears in many places. The injury to apples has been very great. 



The apple-tree tent caterpillar, Olisiocanqm americana Harr., ap- 

 peared this spring on apples in all sections of the State. Many trees 

 were entirely defoliated. In one instance I found a nest in a peach 



^ I have just received a letter from my assistant, Mr. E. D. Ball, bearing date of 

 .June 17, in which he states that the beet caterpillars have been hatching for a week 

 at Kockyford, and that in some fields the beets are half eaten up now. 



