93 



Frequently also the portion of the straw enclosing the gall passes out 

 with the grain because of its weight. These galls, which contain 

 the larvae, should therefore be passed through a sieve and burned m 

 the mill, if not before. There seems to be little danger of infestation 

 of wheat by the insects emerging from the straws in stacks. If the 

 straw is trampled under by livestock or enters commercial channels 

 the adults upon emerging are not likely to find wheat on which to 

 oviposit. 



While the Hessian fly [Mayetiola destructor] infestation in 1918 was 

 heaviest in the north-western portion of the State, in 1919 the greatest 

 damage was further east, the average infestation for the State being 

 14-4 per cent. There has been a distinct increase of this pest in Ohio 

 as a whole since 1918, and the recommended dates for wheat planting 

 as shown on a map should be closely followed, even though late-sown 

 wheat may be threatened with unfavourable weather. The object of 

 the late planting is to delay until most of the adult flies have died 

 without depositing any of their eggs. Examination of experimental 

 plots in Miami county on 30th November 1918 showed the " fly free '' 

 date to be somewhere between 23rd and 30th September, probably 

 about the 25th. As the maximum yield was secured from plots 

 sown between these dates there is every reason for following the 

 recommendation. The ever-growing demand during recent years 

 for more wheat has compelled the farmer to plant part of his acreage 

 very early and continue sowing as late as possible, while avoiding 

 winter injury. Increasing losses from Hessian fly are, however, 

 unavoidable if the fly-free dates are not adhered to. Close co-operation 

 amongst farmers is of course essential in this respect. Miami county, 

 after suffering severe losses for several successive seasons, was cleared 

 of the pest in a single one by this co-operative procedure. If wheat 

 is obviously likely to suffer from either fly or weather the substitution 

 of some other crop is advisable. 



Damage by the wheat midge [Contarinia tritici] was almost negligible : 

 the chinch bug [Blissus leucoptenis] was present in moderate numbers. 



Howard (L. 0.). Report of the Entomologist.— C/./S. Dept. Agric, 

 Bur. Entom., Washington, D.C., 14th August 1919, 27 pp. 

 [Received 30th December 1919.] 



The European corn borer [Pyrmista nubilalis] was recorded in the 

 previous report [R.A.E., A, vii, p. 100] as being estabhshed in Eastern 

 Massachusetts throughout some 500 square miles. Much good work 

 was done in preventing its extension under State appropriations, 

 but in 1919 the requisite Federal appropriation was not granted, 

 with the result that by Augast the moth had spread over an area of 

 1,000 square miles. A great deal of information regarding this pest 

 has been published during the year [R.A.E., A, vii, 224, 411, etc.], 

 and a large number of entomologists are now studying the possibihties 

 of its control. The Hessian fly [Mayetiola destructor] is rapidly 

 increasing in many localities, and wheat-growers have been advised 

 of the most suitable dates for planting in the autumn of 1919. The 

 true army worm [Girphis unipuncta] appeared in numbers, the usual 

 remedies proving successful. It has recently been found that the 

 southern corn rootworm [Diabrotica duodecimpiinctata] does not attack 



