214 INSECT TRANSFORMATIONS, 



keep down the weeds, while the birds and the ichneu- 

 mon flies keep them in check by making prey of them. 



The gregarioU% caterpillars of an allied species, 

 called the black-veined white butterfly {Pieris Cra- 

 tcegi, Stephens), is in some seasons and districts no 

 less destructive to orchards and hawthorn hedges than 

 the preceding ones are to the kitchen-garden. Sal- 

 isbury, who wrote at Chelsea in 1815, says it 'com- 

 mits great destruction every spring, and not (Ally to 

 the apple-trees, but other kinds of fruits.'* Mr 

 Stephens, writing in 1827 says, 'in June 1810,1 

 saw it in plenty at Coombe Wood, and in the follow- 

 ing year I captured several at Muswell-hill, since 

 which time I have not seen any at large. '"j" Mr 

 Haworth also says, ' it has not of late years been 

 seen at Chelsea, where it formerly abounded. We 

 have never met with at all. According to Salisbury 

 the female butterfly lays her eggs near the extremity 

 of an old rather than a young branch, and covers 

 them with a coating of gluten, which is both imper- 

 vious to moisture and impenetrable (this we doubt) 

 to the bills of birds. ' In this state,' he adds, ' we 

 have instances of their remaining without losing 

 their vitality for several years, until a favourable op- 

 portunity of their being brought into existence ar- 

 rives. 'J The caterpillars, which are at first black and 

 hairy, live in common in a silken tent. They become 

 subsequently striped with reddish brown, and disperse 

 over the trees. This caterpillar and its butterfly are 

 figured in a subsequent page. 



Our gooseberry and red-currant bushes are very 

 frequently despoiled of their leaves, both by the 

 speckled caterpillar of the magpie moth (Mraxas 

 grossularicda) , and by what Reaumur terms the 



* Hints onOrcliiirds, p. 56. 



t Illustrations, i, llaustellata, 27. 



X Hints on Orcliards, p, 57. 



