20 



greenish slug, shaped somewhat like a tadpole and having an odor re- 

 sembling that of red ink. This is the larva of a saw-fly, a glossy black 

 four-winged creature about one-fifth of an inch in length. The fly lays 

 her eggs early in June in slits which she makes in the leaves by means of 

 her saw-like ovipositor; these hatch out about a fortnight later, and the 

 slugs begin to devour the leaves, eating out irregular patches and leaving 

 only the skin of the under surface. A second brood is to be found in 

 August. Spraying with powdered white hellebore in water or with Paris 

 green will speedily destroy the slugs. Dusting with lime is also recom- 

 mended on account of its burning properties. Dust of other kinds, such 

 as ashes, road-dust, etc., have been tried, but they merely stick to the 

 slimy surface, and when the insect moults, which it does four times, it 

 leaves its old skin and the dust behind. . This insect is equally common on 

 Cherry-trees and sometimes on Plum. 



Fig. 32. — Pear and cherry-tree slug. 



INSECTS AFFECTING THE PLUM. 



The caterpillars of a number of moths and a few butterflies feed upon 

 the leaves of Plum-trees, such as the large and handsome Plum-tree 

 Sphinx (Sphinx drupiferarum), several Dagger-moths (Acronycta), and 

 others. None of them, however, come in sufficient numbers to cause any 

 appreciable injury to the trees and may therefore be disregarded by the 

 fruit-grower. The most formidable enemy is the notorious 



Plum Curculio (Conotrachelus nenuphar), Figs. 33-34. The work 

 of this insect is so well known that it hardly needs description. The 

 adult is a very small beetle belonging to the family of Snout-beetles, 

 otherwise known as Curculios or Weevils. It is about one-fifth of an 

 inch in length, dark in color, with a pair of shining black humps on the 

 middle of the back, followed by a pale yellowish band ; the snout is short 

 and thick. It looks very much like a rough bit of bark and would there- 

 fore escape notice by those unfamiliar with it. The winter is spent in 

 some hiding place by the adult beetle, which comes out when spring days 

 are warm and flies to the trees in readiness for destructive work. I have 

 often found 'it in the blossoms of plum-trees, probably feeding on the 

 pollen, and waiting till the fruit becomes large enough for its attack. 



