INSECTS. 



" Cabbages, and other esculent ve- 

 getables, are well known to be great- 

 ly injured l)y the caterpillars of two 



different kinds of white butterflies 

 (Fig. 3) ; one of these (Pieris brassi- 

 ccc, c) is much larger than the other ; 



Fig. 3 



the caterpillar is pale yellow, with 

 black spots («) : when full fed, it 

 shelters itself on walls, pales, or 

 trunks of trees, and changes into the 

 chrysalis state (i), in which it still 

 preserves the same cast of colouring. 

 The perfect insect (c) appears early 

 in spring, and continues until the end 

 of summer. The other species of 

 caterpillar is green ((i) ; the chrysalis 

 (e) is of the same colour ; and the 

 butterfly (/) is produced about the 



F,v. 4 



same time as the preceding. Hand- 

 picking the larva, and searching for 

 the chrysalis, are the only plans of 

 destruction, either for these or the 

 gooseberry and currant caterpillars. 

 " Fruit-trees of all kinds, and their 

 produce, are attacked and devoured 

 by a great variety of insects. We 

 shall, however, advert to those cu- 

 rious, minute insects (Thrips Physa- 

 pus, Fig. 4, /, h) so often seen in flow- 

 ers and blossoms during the spring, 



and which, in their natural size (/), 

 appear like short black lines. Near- 

 ly all fruit-trees are liable to consid- 

 erable injury from different species 

 of Coccus, or cochineal insects ; they 

 are mostly so small (F/^. 4, a, </), that 



their form cannot be well distinguish- 

 ed without the aid of a magnifying 

 glass ; many of them resemble small 

 scales, or scabs, fixed on the bark and 

 shoots. One is entirely of a brown 

 colour {Coccus pcrsicorum. a) : when 



427 



