502 
Observations on the various Insects 
As Mr. Kirby's letter to Mr. ^Marsham, dated August '27, 
1795, comprises all that is at present known relative to the 
injurious effects of the Tlirips upou the coni-crops, I shall tran- 
scribe the most important passages :*— " I examined a great 
number of ears, and in them found tliis insect in all its states, 
between the interior valve of the corolla and the grrain. It takes 
Its station in the lonsitudiual furrow of the seed, in the bottom of 
which it seems to fix its rostrum ; probably sucks the milky jm'ce 
which swells the grain, and thus by depriving it of part, and in 
some cases perhaps the whole, of its moisture, occasions it to 
shrink up, and become what the farmers in this part of the world 
(Suffolk) call jmnrjlcd. If your correspondent in Hertfordshire 
means the same insect, he is mistaken in asserting that only a 
single grain in an ear is injured by it. I have myself seen eai"s in 
which fourth part of the grain was destroyed, or materially hurt. 
1 have frequently seen two of the insects upon a single grain, and am 
told that sometimes more are observed. hat is singular, when 
I met with them on the grain in the imago state, they were often 
m pairs, one of which was apterous. These I take to be the sexes. 
I once found a large species, ano aculeato (Thrips aculeata, Mus. 
Kirby) in which the same distinction takes place. The larva of 
Tlirips physapns is yellow, has six legs, which, with the antenna? 
and head, are black and white. Sometimes it is all yellow. It 
is very nimble in its motions, and although brought away in the 
grain soon makes its escape. The pnqm is whitish, with back 
eyes, and wings apparent. It is very slow and sluggish in its 
motions." " There was an orange-coloured powder in every 
grain in which the insect was found, which I imagine is its oxcre- 
menf. All the farmers that I consulted respecting it agreed in 
saying that it did most mischief to the /afe-sown wheats, and that 
such as were sown early received little or no injury. This, I 
think, very probable ; for when the grain is arrived at a certain 
degree of hardness and consistency (which perhaps was the case 
with the early-sown wheats before the insect made any material 
attack), I suppose it is not liable to be hurt. Linnseus saj-s of 
this insect, ' spicas secales inanit;'t but nobody seems to have 
apprehended the injury it is capable of doing to wheat. An in- 
telligent farmer, who first pointed it out to me, assured me that 
he was firmly persuaded that it was this insect which occasioned 
what was called the blight last year, which was the cause of so 
defective a crop. Hie part of one field that I examined, and 
which was particularly injured, was to the north of a high hedge : 
• Vide Linn. Trans., vol. iii. p. 246. 
t Viz., " it empties the ears of rye." — Linnaeus's Sys>t. Nat., vol. i. 
yais 2, p. 743. 
