ON THE LAMELLICORNES. 5^7 



of the cock-chafers, when they were mixed in a tolerably large 

 quantity with earth, in a pot or box. But these experiments 

 did not svicceed so well in a field, because the turf and the 

 ashes had not been put there, either in sufficient quantity, or 

 at a sufficient depth. The most proper time for spreading 

 these substances, and mixing them with the earth, would be 

 in spring, without doubt, at the moment in which the larvae 

 quit their retreat, and re-ascend to support themselves upon 

 roots. 



Fifth Method. — All the means hitherto mentioned have 

 proved either useless or insufficient. The best would doubt- 

 less be, as Rosier informs us in his Course of Agriculture, to 

 make, for several years in succession, a general chase of those 

 insects, and to destroy them when in their final form. For 

 this purpose women and children might be employed. The 

 birds of the farm-yard, such as turkies, hens, &c., nocturnal 

 birds, such as the difterent species of owls, &c., rats, weasels, 

 ferrets, and all their congenerous quadrupeds, cause a great 

 number of them to perish. Some carabi also destroy a great 

 quantity of female cock-chafers, at the moment in which they 

 are trying to descend into the earth for the purpose of depo- 

 siting their eggs. 



It is commonly believed that frost and the cold rains of 

 spring, cause the cock-chafers to perish before they issue from 

 the earth. It is also believed, according to the observations 

 of Roesel, that one may predict, from the number of cock- 

 chafers in one year, their dearth or their abundance for the 

 fourth year which will follow the prediction. But observa- 

 tion does not confirm these assertions, which are founded 

 rather on conjecture than experience. It often happens on 

 the one part, that after a rigorous winter, and a cold and 

 humid spring, that the cock-chafers appear in great abundance 

 in the month of May, and that they are sometimes less nu- 

 merous after a mild winter and a dry and warm spring. On 



