APPENDIX 191 



soot, &c., while the dew is on the leaves, so that the dust 

 sticks on well. The ground under the bushes should 

 be dressed with gas lime before forking it over in the 

 spring, or the surface soil may be removed in the autumn, 

 and buried in a hole dug for the purpose. It should 

 be replaced by the soil from the hole and manure. 



The Slugworm is the larva of the Pear Sawfly 

 (Selcmdria ■ atra), also known as Tenthredo cerasi, 

 Eriocwmpa limacina. It is a lampy, blackish grub, 

 about half an inch long, largest towards the head end, 

 and covered with a black slime which exudes from its 

 skin. It devours the upper surface of the leaves of the 

 pear and cherry, leaving the veins and lower skin, which 

 causes them to turn brown and fall. They emit a 

 sickening odour when in large numbers. At their last 

 moult, they cast their black skin and become buff- 

 coloured and wrinkled. The larvas turn to pupae in the 

 autumn, pass the winter underground in that state, and 

 appear as sawflies about July. 



These are stout-bodied, shining, black little flies ; 

 their front wings, measuring about half an inch from 

 tip to tip, are membranous, netted, and often stained 

 with black. The larvee should be dusted with quick- 

 lime or gas Ume, a second application closely following 

 the first, as they are able to throw off the first by ex- 

 uding their slime. The trees may also be syringed 

 with strong soapsuds, tobacco water, &c., and cleansed 

 with pure water afterwards, or the larvse may be hand- 

 picked. The ground under the trees may be treated 



