affecting the Clover-crops and Pasture-lav ds. 45 



the wing-cases are then of a grey colour, but they soon assume 

 their proper tint. 



I doubt not that these weevils are annually produced in great 

 numbers, for they are common everywhere. I may mention, 

 however, that they were particularly abundant in Surrey and 

 Suffolk in 1840 and 1841, and they were in profusion in the 

 clover-fields in Middlesex. Some idea may be formed of the 

 ravages occasioned by this weevil from the following communica- 

 tion made to me in September, 1844, by Mr. Wm. Trenchard of 

 Sherborne : — 



" I have a field of clover which has been twice mown, and there is now a 

 fine aftermath. The part of the field near the stack has been lately attacked 

 by a small black weevil, which advances in a semicircle, totally destroying 

 every leaf, leaving only the fibre. I should think there are on some of the 

 leaves as many as 100 or 150. Since last night they have eaten nearly as 

 much as wonld have kept a sheep. In September they seemed to have been 

 somewhat weakened by the late heavy rains. They destroy every leaf in 

 their progress." 



When one sees in a field of clover, which is in flower, patches 

 of discoloured or brownish heads which appear to be withered, 

 it is a certain indication of the presence of these weevils. 



This destructive weevil is no new pest, for its economy was 

 known to Linnaeus, and was verified by Mr. Markwick as long 

 back as the year 1800 ; and in 1801 the latter communicated his 

 observations to the Linnaean Society.* In Mr. Markwick's case 

 the larvae were in full force in the beginning of August, and 

 changed to pupcB in the middle of the same month ; and at the 

 same time the weevils were hatching. The damage done at this 

 time is accurately shown by figures, for he states that in 



" 1798 T grew on 9 acres of ground (just double tlic quantity that was 

 saved for seed this year) either 33 or 34^ bushels of clover-seed, of which 

 28^ bushels were sold for 50s. per bushel, and the rest, amounting to cither 

 5 or 6 bushels (I am not quite certain which) was kept for my own use ; so 

 that, taking it at the lowest, the statement will stand thus : — 



Bushels. £. s. d. 



In 1798 four acres and a half, 1 , ^-.n^ i-i, ^^ f ,)ii-'c 



■1 • 1 ir /-.i \ produced IG^, which sold lor .. 41 Ir b 



being half of the crop .. J -^ ^' 



This year (1800) the samei 



quantity of ground pro- J. ,, 73, worth at same price 18 15 



duced only J — 



Deficient .. .. 9i .. .. worth £23 2 6 



Thus it appears that the loss on this year's crop is very great, occasioned, 



most probably, by the depredations of this insect ; and besides, what seed I 



have is of an inferior quality." 



In 1843 a valuable pamphlet upon the insects injurious to 

 agriculture was published by M. Guerin Meneville,t in which 



* Trans. Linn. Soc, vol. vi. p. 142. 



t Extrait des Memoires de la Socie'te Koyale et Centrale d'Agi-lculture, annee 

 1842. 



