ENTOMOLOGY. 863 



wheat in Ohio during the fall of 1899 and the spring of 1900. The 

 conditions which were favorable to the relative abundance of the 

 Hessian fly were the decrease in the number of its natural enemies, 

 a mild autunni, and a severe drought which retarded the development 

 of the fall brood to such an extent that the flies emerged in time to be 

 most destructive to late sown wheat. The Hessian fly emerges about 

 one month earlier in the fall over the northern parts of the State than 

 in the southern parts. Throughout Ohio, except in the northwest 

 and southwest portions, the rainfall in August, 1899, was below the 

 normal. During September the temperature was low and heavy rains 

 occurred on the 18th and 25th of this month. Soon after these rains 

 the fall brood of the Hessian fly emerged and attacked the j^oung 

 wheat which required a longer time than usual for germination on 

 account of the drought. The author believes that the Hessian fly will 

 probably continue to be very destructive for another season. It is 

 possible, however, for the farmer to regulate to some extent the time 

 of sowing wheat by the weather conditions, remembering that the fall 

 brood of the Hessian fly emerges within a few days after a heavy 

 rainfall. It is not advisa])le to sow wheat for 2 successive years on 

 the same ground and it should be remembered that the Hessian fly 

 attacks rye and barley as well as wheat. 



The Hessian fly in West Virginia and ho-w to prevent losses 

 from its ravages, A. D. Hopkins {Wed Virginia Sta. Bui. (J7 ^ pp. 

 %S9-^5If-., pils. '2., 'map 1). — The author gives a brief summary of the 

 life history of the Hessian fly. In West Virginia there are 2 broods 

 of this insect a 3'ear, and the time of appearance of the fall brood is 

 modified more b}^ altitude than by latitude. The author gives a brief 

 statement of the ordinar}^ methods used in controlling the Hessian fly, 

 including burning of the stubble, plowing under stubble, destruction 

 of volunteer wheat, sowing trap strips of wheat, and crop rotation. 

 It is stated that the period for sowing wheat extends over about 15 or 

 20 days, beginning about a week earlier than the average date for the 

 disappearance of the fall brood of Hessian flies, and ending from 1 week 

 to 16 da3's later than this date. The disappearance of the fall swarm 

 or period of active flight is, according to the author, governed by a 

 natural law which "causes it to vary at the rate of about 1 days for 

 each degree of latitude (earlier toward the north and later toward 

 the south) and 1 da3's earlier for each 100 feet of altitude above sea 

 level." The average dates for the disappearance of the fall brood in 

 difl'erent parts of the State are given on a map which accompanies the 

 bulletin. 



Experiments with insecticides upon potatoes, C. D. Woods 

 {Maine Sta. Jjiil. US., pp). lGD-192). — This bulletin contains a report 

 upon experiments with several commercial insecticides in comparison 

 "with Paris green as a remedy for the potato beetle. For these experi- 



