INSECTS ON PEAR-TREES. 271 INTERMEDIATE STOCKS. 



themselves in the ground like the cock- 

 chafer. 



Among the moths, the rose tortrix 

 (Tortrix Btrgmanniana) is distinguished 

 by the rich golden yellow of its breast and 

 fore-wings, slightly clouded with orange, 

 and bars of purple-brown with silvery 

 scales. This moth, in the caterpillar state, 

 is very destructive round London to roses. 

 The moths deposit their eggs in the 

 summer in the incipient buds, and they 

 commence operations as soon as they 

 appear, attaching themselves back to back 

 by their thread-like fibres. Round these 

 leaves others grow in distorted shape, 

 while the caterpillar revels on its core, 

 devouring the petals of the flower as well 

 as the leaf. When disturbed, the cater- 

 pillar drops down, suspended by a thin 

 web which it spins, and by which it is able, 

 when the danger disappears, to resume its 

 former position. The only method of 

 destroying these insects is by sharply 

 pinching the buds where they are suspected 

 to be in the early spring ; this will relieve 

 the plant, and enable it to throw out fresh 

 leaves. If allowed to arrive at maturity, 

 the moths should be destroyed as soon as 

 they appear, and before they can deposit 

 their eggs. The ashy-white bell-moth 

 (Spilonota aquana] is another moth of the 

 Tortricidce, which has been reared from 

 the leaves of the rose, and of habit similar 

 to the preceding. The yellow-tail moth, 

 which has usually been found on the oak, 

 the elm, and the blackthorn, has also been 

 found on Scotch roses, feeding upon the 

 petals, and afterwards attacking the leaves. 

 This moth appears at the end of July, and 

 the caterpillar (which is thickly coated 

 with long black hairs) feeds also on the 

 pear. 



Insects on Pear-Trees. 



Pear-trees are subject to the attacks of 

 several species of lepidoptera, saw-flies, 



and aphides. Among the lepidoptera, the 

 beautiful moth Zeuzera pyrena, with its 

 antennae feathered on each side, is fur- 

 nished with an elongated telescope-like 

 ovipositor, with which the female deposits 

 the eggs to a considerable depth in the 

 crevices of the bark of the tree. The per- 

 fect insect appears in July, and the cater- 

 pillars in August, when they immediately 

 burrow into the wood of the tree. In 

 September they moult, and in the follow- 

 ing June they are full-grown. Sparrows 

 are the gardener's best ally in destroying 

 this insect in the perfect state. Several 

 other small lepidoptera are injurious to the 

 pear. Tinea clerckella, one of the Tineidae, 

 deposits its eggs on the under surface of 

 the leaves towards the end of May. The 

 young larvae penetrate the under cuticle, 

 and feed on the fleshy parenchyma, 

 leaving the surfaces untouched, giving the 

 leaf a flabby and blistered appearance. 

 The Chaumontelle is said to be particularly 

 subject to the ravages of this creature, 

 especially in the beginning of autumn. 

 The Selandria ^Ethiops, or Pear Saw-Fly, 

 is particularly destructive to the leaves of 

 pear trees in July, August, and September, 

 which are then infested by its grub, 

 generally known as the slimy grub. The 

 Aspidiotus ostreafornis, or Pear Tree 

 Oyster Scale, is one of the pests that infest 

 pear-trees. The Aphis pyrimali* or Pear 

 Tree Aphis, attacks both the pear-tree and 

 the apple-tree. 



Intermediate Stock (not. ord. 

 Cruciferae). 



The Intermediate Stock, Mathiola annua 

 intermedia, is a half-hardy biennial sup- 

 posed to be a cross between the Ten week 

 and Brompton stocks. It is dwarf and 

 branching, and in the early summer 

 months constitutes the principal feature in 

 furnishing pots, vases, window boxes, &c. 



