TWO INSECTS AFFECTING WHEAT AND BARLEY CROrS. 



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TWO INSECTS AFFECTING WHEAT AND BAKLEY CEOPS. 

 By Feed Exock, F.L.S. 

 [Read July 19, 1910.] 



It will be better probably to confine my remarks to one or two of 

 the worst of the insects attacking wheat which have made their appear- 

 ance in Great Britain, than to attempt to deal with all that are known, 

 for their name is legion. 



It will be within the recollection of many that in the year 1886 

 the "Hessian Fly," which in the United States of America does an 

 enormous amount of damage, amounting to hundreds of thousands of 

 pounds per annum, was discovered by Mr. George Palmer, of Eevells 

 Hall, Hertford, who found it doing considerable damage to the barley. 

 Few entomologists were acquainted with the appearance or life-history 

 of the pest at that time, and it was practically unknown to those who 

 were ofFLcially connected with agriculture. Indeed, though twenty-four 

 years have passed since then, much ignorance still prevails concerning 

 it, even among those whose business it should be to make themselves 

 acquainted with the pests of our crops. 



I have been , frequently asked " What is the ' Hessian Fly ' like? " 

 "How does it affect the wheat?" Sec. I think the best reply to 

 these questions will be to describe the entire life-history as I worked 

 it out in the fields at Eevells Hall, where Mr. Palmer first dis- 

 GOYered it, and to whom I am greatly indebted not only for facilities 

 for making observations of its habits, but also for supplying me 

 with screenings during three seasons, so enabling me to confirm its 

 life-history, which, though the Hessian Fly had been known in America 

 for nearly a hundred years, had never been worked out. I was also 

 able to disprove satisfactorily Wagner's statement that the Hessian Fly 

 could not have been introduced into the United States in the straw 

 mattresses of the Hessian troops, as the time taken in travelling from 

 Hesse-Cassel to Long Island — four months — would be too long for 

 the larvae to survive. 



On March 9, 1889, I received from Mr. Palmer a small bag of 

 screenings of the harvest of 1887. On examination of these I picked 

 out over one hundred puparia, all apparently dead; but, on carefully 

 opening some, I found the contained maggot to be just alive — and only 

 just. These I placed on damp soil, the moisture from which revived 

 them in the course of a few days ; and ultimately some changed to 

 pupae, from which the first fly appeared on May 9, 1889, and others 

 followed in a few days after, having been in a retarded state for two 

 years, a much longer time than that occupied by the Hessian troops in 

 their journey from Hesse-Cassel to Long Island, and fully justifying the 



