1074 EXPERIMENT STATION RECORD. 



the proportion of 1 lb. to 75 gal. of water with the addition of a pound 

 of lime. 



An extensive bibliography is appended to the bulletin. 



The Hessian fly in the United States, H. Osborn ( U. 8. Dept. 

 Agr., Division of Entomology Bui. 16, n. ser., pp. 57, pis. 2, figs. 8, map 

 1). — The original home of the Hessian fly is left in doubt, with the sug- 

 gestion that it probably was the same as that of wheat. The distribu- 

 tion of the insect is practically coextensive with the wheat-producing 

 regions of Europe and America. The author mentions two means of 

 distribution of the Hessian fly; the first and less important is the 

 slight power of flight, while the chief means is transportation in straw 

 containing puparia or flaxseeds. " The introduction into the United 

 States near New York City has as its most probable foundation the 

 straw used as bedding by the Hessian troops landed during 177G and 

 1777, and while there is lacking positive evidence that the insect 

 existed at the point of their starting or even of embarkation, the source 

 of straw they might have used and scattered after landing may have 

 been in some infested locality." A careful description is given of the 

 entomological details and of the life history of the insect, including the 

 3 larval forms and the pupal. 



As to the question of the number of broods per year, the author 

 believes that in the northern and eastern part of the country the insect 

 passes through 2 broods per year, but that temperature and moisture 

 conditions have a great influence in retarding or accelerating develop- 

 ment. "The Hessian fly presents variations not only in the number of 

 broods, from 1 to possibly 5 or 6, depending upon latitude, but by acceler- 

 ation or retardation, under conditions peculiar to each year, it may appear 

 earlier or later and in a greater or less number of broods in the same local- 

 ity. This variation naturally enhauces the difficulty of stating life his- 

 tory details with precision and making recommendations as to particular 

 dates on which to adopt measures of control." Certain authorities 

 have recorded the Hessian fly as having been found upon a number of 

 cultivated grasses. The author, however, does not accord accuracy to 

 these observations, but states that "in any deductions relating to the 

 control of the Hessian fly, it may be considered for all practical pur- 

 poses that the insect lives only on wheat, rye, or barley, and will not 

 perpetuate itself on other plants." An account is given of the different 

 effects on the host plants depending upon whether the attack is made 

 in the spring or fall. 



Under the head of the natural enemies of the Hessian fly the author 

 lists a number of primary and secondary parasites as found in this 

 country, and gives a list of parasites as recorded in Russia, England, 

 and France. The primary parasites found in this country are described 

 and figured, and an account is given of their biologioal relationship. 

 The author gives a history of the introduction by Dr. Riley of the para- 

 site Entedon epigonus from Russia, and of the success of its introduction. 



