HYMENOPTKEA. 175 



others swinging aerial nests (^Vespa sylvestiis), — they consist of 

 a series of layers of cells, one deep. These layers or plat- 

 forms are connected by vertical pillars one above another. The 

 comb and cells are made of a papery substance ; so also is the 

 envelope enshrouding the layers of cells. This substance is 

 made by the wasps chewing up decayed wood, the scrapings of 

 the bark of trees, and the green slimy matter off water, mixed 

 into a pulp with saliva : this dries into a greyish or tawny kind 

 of paper. The opening is in the under side. The food consists 

 chiefly of insects in the early part of the year, but later they 

 attack fruit, and even rob bees of their sugary stores. 



The commonest English Wasps are Vespa vulgaris, the Com- 

 mon Wasp ; Vespa sylvestris, the Wood Wasp ; Ves2ja rufa, the 

 Tawny Wasp, common in sandy districts ; and Vespa crahro, 

 the hornet. Eight species are found altogether. The sting is 

 in the form of a double-edged saw, with poison-bags at its base. 

 Unlike the hive-bee, the wasp can sting any number of times. 



Solitary Wasps are known as Sand Wasps or Odyneri ; the 

 fifteen British species are all more or less beneficial. They 

 are smaller than those of the genus Vespa, and never live in 

 colonies. They form burrows in sandy banks, with curved and 

 tubular entrances, composed of pieces of mud. Like the wasps, 

 they are all of some shade of yellow and black in colour. They 

 provision their nests with small larvae and weevils in a paralysed 

 condition. 



Remedies for Wasjjs. — The ground nests of V. vulgaris, 

 V. rufa, &c., are best destroyed by burning sulphur in them of 

 a night and blocking the nest up with clay ; then digging them 

 out next day, and burning the whole brood. Cyanide of 

 potassium is often employed, but with no better results than 

 sulphur, unless the nest is dug out afterwards in the same way. 

 The hanging nests of V. sylvestris are more troublesome : by 

 far the best plan is to shoot them down, late in the evening. 

 Needless to say, all the spring queens should be killed 

 whenever one can do so. 



