Till. 
REPORT ON INSECTS OBSERVED IN HERTFORDSHIRE IN 1887. 
By F. W. Silvester, F.R.Met.Soc. 
Read at Watford , 8th May , 1888. 
The prolonged warm weather and long droughts of last summer 
in all probability had much effect in causing the unusual amount 
of insect damage observable during the period embraced in this 
report. It may be interesting to note that the mean rainfall of the 
whole of the British Isles in 1887 was only 25*8 inches, whereas 
the mean for the 21 years, 1866 to 1887, was 35*3 inches, so that 
there is a deficiency of nearly 10 inches in 1887. Last year was in 
fact the driest we have experienced since 1866. 
Foremost amongst the injurious insects of the year is the Hessian 
fly, which, it will be remembered, was brought under Miss E. A. 
Ormerod’s notice in 1886, near Hertford. On 15th July, 1887, 
our President, Mr. F. M. Campbell, wrote to Miss Ormerod : 1 ‘I am 
sorry to say that the Hessian fly is not only plentiful in Mr. 
Palmer’s fields, but here also. Here I have found it in wheat close 
to the root.” On the 19th Mr. Campbell forwarded samples of the 
attacked wheat, with the note : “ Most of them are on the first 
joint, and one stalk has been visited both on the first and second 
joint. It is evident that most of the puparia about us in wheat 
will be left on the field after reaping. . . . Cecidomyia destructor 
may be said to infest our whole parish.” And on the 26th Mr. 
Campbell added : “ Hessian fly to my knowledge is over the whole 
of Hoddesdon, Ware, and Hertford districts.” On July 23rd, Mr. 
Arthur Smith, of Smallford, St. Albans, forwarded specimens of 
Hessian-fly attack found by him in two wheat fields at Hill End 
Farm. Of three fields of wheat contiguous to each other, amounting 
to fifty acres, one field, clover in 1886, and sown at the end of 
October with Webb’s challenge wheat, had no attack. Of the 
other two fields, part of one, fallow in 1886, sown with mustard 
ploughed in, and with Webb’s “ challenge ” on Sept. 17th, also 
had no attack; but the other part, which had swedes carted off and 
was sown with April wheat on April 12th, was mildly attacked. 
The remaining one of the three contiguous fields, part fallow and 
mangolds, remainder peas in 1886, sown with Webb’s “ challenge” 
in the beginning of October, was more severely attacked. Both 
pieces of fallow attacked were partly manured with London stable- 
manure, but the portion of fallow not attacked, with artificial 
manure. Miss Ormerod adds: “ From the above it appears that 
both the spring- and autumn-sown wheat on the fallow were 
attacked where London manure was used.” 
The destruction of the “ flax-seeds” found after threshing in the 
siftings is the most sure way of guarding against a recurrence of 
this pest. Deep ploughing is good, and the Americans advise 
putting all infested straw in good square ricks, so that a large pro¬ 
portion of the flies which come out of the flax-seeds are destroyed, 
