86 



CORN AND GRASS. 



found in maggot state, nearly and quite full fed, as well as puparia. 

 Here, again, a third of the crop was considered to be destroyed. This 

 attack was after mown Clover, and the crop sown the first week in 

 November, 1890. 



A third attack was reported from Helsey on the 19th, but not exa- 

 mined, as the damaged crop had been ploughed up. The previous 

 rotation had been : — 1889, Oats ; 1890, fallow, crop sown 1st Nov. ; 

 1891, resown with Barley 8th May, 



Mr. Eardley Mason added the very noteworthy observation that in 

 all the cases the headlands were not at all, or very slightly, affected. 



The following observations, also, by Mr. E. Mason, are of practical 

 value, as showing no noticcftble presence of the attack in wild Grasses. 

 The remarks as to non-presence of the attack in wild Grasses were in 

 reply to my own inquiries, turning on the point of some of our Corn 

 insect-pests being double-brooded ; and that in this case, if, like the 

 " Frit Fly " in Oats and Barley, the spring attack took place in the 

 young shooting plant, and the summer one in the ear, we should thus 

 gain a good clue towards prevention. I suggested Grasses, as these 

 might be found on neglected fallows, or in the noticeably thin crops 

 sometimes preceding Wheat-bulb maggot attack. 



Mr. Eardley Mason wrote me on the 24th of May: — "I doubt 

 much whether H. cnarctata will be found to have a summer brood. The 

 larva is so large that I can scarce believe that the damage caused by the 

 summer-born host could have escaped notice. For the last three years 

 my eyes have been at work detecting injured Grasses in hedgerows and 

 by roadsides. With scarce an exception the cases have been of fungoid 

 disease. In no case has there been an approach to injury like that of 

 H. coarctdta. 



Further on Mr. Mason notes that "It is true that the headlands get 

 the most trampling, and are thereby consohdated ; and if it should 

 be the case that the fly lays its eggs in the broken-up soil before sowing, 

 one can understand how many eggs must be so closely compacted as 

 to render the emergence of the larvfe impracticable." .... " If the 

 fly lays its eggs in spring, I wholly fail to understand why headlands, 

 and Wheat after seeds, escape." 



The following observations were kindly sent me by Mr. William 

 Parlour, of Middle Farm, Dalton-on-Tees, Darlington, regarding some 

 points on which I enquired of him, especially those suggested by the 

 absence of attack on trampled or "firmed " ground, as on headlands. 

 The first observation is as to infestation in spring-sown Wheat : — 

 " I have never known of the maggot being found in spring-sown 

 Wheat, but I have had very little opportunity of observing, for the 

 quantity of Wheat sown in the spring in this district is very small 

 indeed." 



