88 CORN AND GRASS. 
The chrysalis is rather smaller than the maggot, reddish-brown in 
colour, more pointed at the head than at the tail extremity, which 
latter appears from the size of the wart-like spiracles, which it bore in 
maggot state, to be strongly cleft. The branched external spiracles, 
or ‘‘air-tubes,”’ near the head, are also for a time clearly noticeable. 
The maggots turn to chrysalids in the dying remains of the outside 
leafage of the plants in which they have fed, and from these (in the 
most specially recorded notes which I took) Frit Flies were appearing 
about the 9th of July. 
Weather influences may be said to have very great effect on this 
attack, as it has been found that late-sown Oats suffer very much more 
from it than those put in earlier; consequently if from prolonged cold 
or rain in late winter, or early spring (as well as from other causes), 
the Oat-sowing is delayed, the crop is likely to suffer conformably. 
The following notes, sent me in 1888 (the great Frit Fly year) by 
Mr. W. McCracken, Professor of Agriculture at the Royal Agricultural 
College, give definite valuable observation on this point. 
Writing to me from the College on the 4th of July, Prof. McCracken 
observed :—‘ I send you a few specimens of Oat affected by a small 
grub [that of the Frit Fly, Ep.]. I am sorry to say a very large area 
in this part of the country has suffered similarly. The crop from 
which these specimens are taken is practically destroyed, except for 
hay. Winter Oats and all early spring-sown fields seem to have escaped.”’ * 
A few days later, examination of one of the badly attacked fields 
alluded to showed damage roughly estimated by Prof. McCracken as 
90 per cent. of crop gone. 
In 1889, Prof. McCracken wrote me again, from the Royal Agricul- 
tural College, on the same subject at the beginning of August:—‘ The 
Frit Fly has again been the most plentiful of injurious insects, and, 
as was the case last year, the degree of injury corresponds to the date 
of sowing. For example: in one field Black Tartarian Oats (the 
sort most largely grown here) were sown on March 29th, and en- 
joyed almost complete immunity from attack; in another field, 
sown on April 29th, over seventy per cent. of the first stems were 
destroyed.”’ 
The following note, sent on the 17th of June in the past season 
from Ossemsley Manor Farm, Lymington, Hants, by Mr. D. D. Gibb, 
shows bad attack following on late sowing, and also the additional 
evil of unfavourable weather for growth accompanying the attack, and 
preventing the injured plants doing something towards returning a 
crop by tillering. This (as it is unnecessary to say), both from 
* I add italics to the above and the following passage to draw attention to the 
point of early sowing.—Ep. 
