122 INSECT PESTS 



mencing in March, can be responsible for 23,000,000 

 descendants before October is out. The insect was first 

 brought from America, has been known in EngHsh 

 vineries since 1865, and is now common enough through- 

 out the world. 



The Hymenoptera are chiefly represented by the 

 Common Wasp {V(Spa vulgaris) and the Hornet (F. 

 crabro) against which nest-destroying campaigns are 

 famihar enough throughout the country. 



There is, by the way, a friendly genus of Sand-wasps, 

 which Uve in walls and dry places, Odyneri by name, 

 which go hawking after weevils, pouncing upon them, 

 stinging them to death and carrying them away bodily as 

 food for their young. The Odyneri are easily distin- 

 guished from the common wasp as they have no yellow 

 belts across the abdomen. (See Plate 24.) 



I should have mentioned also that there is one count in 

 favour of millepedes in that they feast upon the root- 

 feeding vine louse, though most folks would think it 

 scarcely sufficient warranty for welcoming their presence. 



Leaving insects we have still to notice the Red Spider 

 or Spinning Mite (Tetranychus) which has almost as much 

 power of reproduction as the Vine Louse. It lays its eggs 

 in between the ribs of the leaves, and the spiders are 

 full-grown in from ten to fourteen days. Tobacco fumiga- 

 tion is helpful and can be done whilst the plants are in the 

 house, other and more drastic methods, such as cyanide 

 or sulphur poisoning, having to be arranged for when 

 everything has been cleared out. (See Plate 24.) 



Our notice of Vine pests may be concluded %vith a 

 reference or so to fungi, as although outside the province 

 of this chapter, they are often as troublesome as insects 

 to the grower. 



First there is the Powdery Mildew of the Vine {U. 

 spiralis), a plant parasite which is supposed to have come 

 over from the United States, where it occurs as a natural 

 ailment on wild grape as well as on cultivated forms. 



