452 THE INSECT WORLD. 
rape-seed, very thickly, which you must then bury by a very deep 
ploughing, when it is as high as your hand. The colewort, they 
say, kills the larvee, while it at the same time manures the soil. 
Or again, you must plough up the land on the approach of hard 
frosts, to expose the worms to the cold. Lastly, you can water 
the field with oil of coal, or sprinkle it with ashes of boxwood. 
All these are expensive. The simplest means are here the best. 
It is better to depend upon labour than destructive substances, 
whose employment always presents inconveniences. Considering 
the difficulties which oppose themselves to us in our search 
after larve, we had better collect them in their adult state 
by violently shaking the branches of the trees on which they 
doze during the day, and then kill them in some way or other, 
thus destroying from twenty to forty eggs with each female. A 
general cockchafer hunt, rendered obligatory by a law, and 
encouraged by prizes, would be the only efficacious means of 
opposing a pest which costs agriculture many millions. This 
means would also be less costly than the turning up of the land 
concealing the larve, when it is remembered that they prefer 
land in full bearing. 
In 1835, the General Council of La Sarthe voted a sum of 
20,000 franes for a cochchafer hunt. Nearly six hundred thousand 
litres were delivered in, thanks to a prize of three centimes per 
litre. Asa litre contains about five hundred cockchafers, there were 
thus destroyed about three hundred millions of them. It is true 
that M. Romieu, then Prefect of La Sarthe, who was the principal 
promoter of this excellent measure, became food for the wit of the 
newspapers, and was represented dressed like a cockchafer in 
the Charwart. Derision and ridicule are too often the reward of 
useful ideas. In Switzerland were taken, in 1807, more than one 
hundred and fifty millions of these insects. But these isolated 
measures were useless in producing a durable result. 
It has been tried to make use of cockchafers in industrial arts. 
According to M. Farkas, they have succeeded, in Hungary, by 
boiling them in water, in extracting from them an oil, which is 
used to grease the wheels of carriages; and, according to M. Mul- 
sant, the blackish liquid which is contained in the cwsophagus 
may be used for painting. But the produce arising from these 
