88 



Observations on the various Insects 



I have now to give the history of the second army attacking the 

 potatoes, and which is unquestionably an enemy to the cultivator, 

 for these insects subsist upon the tubers and roots, both injuring 

 and reducing the crop. 



The potato-disease in France so greatly alarmed the nation on 

 its first appearance, that Monsieur Guerin-Meneville was charged 

 by the Minister of Agriculture and Commerce to draw up a 

 Report, which was read before the Academy of Sciences in 

 October, 1845, and afterwards published in one of the French 

 Journals.* As M. Guerin has also been appointed by the 

 Government to investigate the origin of the disease in the Silk- 

 worm caterpillar, called Muscardine,\ which is a species of fungus 

 attacking living animals, his opinion becomes so important that I 

 may be excused for introducing his observations before I proceed 

 with my disquisitions. In addressing himself to the Entomolo- 

 gical Society of Paris regarding " the malady which has for a 

 long time spread itself over the potato-crops," he says, "many 

 persons attributed this epidemic erroneously to insects, whilst it is 

 now demonstrated that it is produced by a malady of the plant, 

 caused by colds which were felt at the end of the spring, and by 

 the extraordinary humidity of the summer, which favoured the 

 production of a Cryptogame that developed itself in great 

 numbers in every one of the cells of the potato. The insects and 

 larvae that have been found in spoiled tubers have come there 

 when the potato has been partly decomposed by the fungi, and 

 cannot be regarded as having caused the malady. "J 



Although I have discovered a great many insects affecting the 

 tubers which are not recorded in M. Guerin's Report, there are 

 many no doubt which have not yet fallen in our way. I shall 

 commence with those which live upon and of course injure the 

 healthy and sound tubers. Amongst these are the 



Surface Grubs. 



In July, J 844, I received some caterpillars from H. W. B., of 

 Bedminster Lodge, near Bristol, stating that they were all taken 

 on the 26th of July from one plant in a field of potatoes : " They 

 attacked the haulm just beneath the earth and ate through it. 

 Acres of potatoes in this neighbourhood have been attacked by 

 them. Some bore into the potatoes and destroy the small ones. 

 They have also spoiled scores of celery plants and bored into the 

 crowns of the carrots, indeed nothing seems to be free from them." 

 They were the caterpillars of a moth, the Noctua (Agrotis) 



* Bulletin des Seances de la Soc. Royale et Centrale d'Agric, vol. v. 

 p. 331. 



f Annales de la Soc. Sericicole. 



% Ann. Soc. Ent. de France for 1845, vol. hi. p. Ixxxvi. 



