172 



INDIRECT INJURIES CAUSED BY INSECTS. 



it by alluding Avith M. Walckenaer to the insects only occa- 

 sionally injurious to the vine, you are perfectly aware of the 

 eagerness with which wasps, flies, and other insects, attack the 

 grapes when ripe, often leaving nothing but the mere skin for 

 their lordly proprietor. 



There are some of these creatures that attack indiscrimi- 

 nately all fruit-trees. One of these is the Cicada septemdecim 

 (so called because, according to Kalm, it appears only once in 

 seventeen years ^ ). The female oviposits in the pith of the 

 twigs of trees, where the grubs are hatched, and do infinite 

 damage both to fruit and forest-trees.^ Birds greedily devour 

 them ; and a curious fact is mentioned by Dr. Harlan of Phi- 

 ladelphia ( who confirms their septemdecenary appearance), that 

 young fowls which eat them lay eggs with colourless yolks.^ 

 Another, the caterpillar of the butterfly of the hawthorn 

 {Pieris cratcegi), which, in 1791, in some parts of Germany, 

 stripped the fruit-trees in general of their foliage.* In France 

 also, in 1731 and 1732, that of a moth, which seems related to 

 the brown-tail moth {Porthesia auriflua), whose history has 

 been given by the late Mr. Curtis, was so numerous as to oc- 

 casion a general alarm. The oaks, elms, and white-thorn 

 hedges looked as if some burning wind had passed over them 

 and dried up their leaves ; for, the insect devouring only one 

 surface of them, that which is left becomes brown and dry. 

 They also laid waste the fruit-trees, and even devoured the 

 fruit; so that the parliament published an edict to compel people 

 to collect and destroy them ; but this would in a great measure 

 have been ineffectual, had not some cold rains fallen, which 

 so completely annihilated them, that it was diflicult to meet 

 with a single individual.^ In Germany, according to M. 

 Schmidberger, the larvae of the following moths, Porthesia 

 clirysorrhcea, Clisiocampa neustria, Hypogymna dispar, Epi- 

 serna ccBruleocephala, Yponomeuta padella, and especially Chei- 



sects injurious to the Vine (Ann. Soc. Ent. de France, iv. 687.), it is the Coccus 

 adonidum which is injurious to vines in hot- houses in France, while the Coccus 

 vitis attacks those in the open air. 



1 Travels, ii. 6. ^ Collinson in Philos. Trans, liv. x. 65. 



3 Trans. Ent. Soc. Lond. i. proc. xxx. 



4 Rosel, I. ii. 15. ^ Reaum. ii. 122. 



