VESPIDAE WASPS' NESTS 



8l 



which is probably chiefly glandular products. Our British 

 Vespidae number only eight species, all belonging to the one 

 genus Vespa, and yet they exhibit three different modes of 

 nidification. Vespa vulgaris, V. germanica and V. rufa form 

 subterranean nests, while V. arbor ecu, V. sylvestris and V. norvegica 

 suspend their habitations from the branches of trees, bushes, or 

 strong annual plants. Vespa crabro, the hornet, usually adopts 

 an intermediate course, forming its nest above ground, but in a 

 spot where it is protected and concealed. 

 The favourite habitat of this formidable 

 Insect is the interior of an old tree, but 

 the hornet will sometimes avail itself of 

 the protection of a thatched roof. Both 

 it and other arboreal species are said, 

 however, to occasionally make subter- 

 ranean nests. It is ascertained that 

 V. austriaca, the eighth species, is an 

 inquiline. 



De Saussure, 1 the monographer of the 

 social wasps, classifies them according to 

 the architecture of their nests. He estab- 

 lishes three groups: (1) Stelocyttares, in 

 which the layers of comb are not con- 

 nected with the envelope, but are sup- 

 ported by pillars made by the wasps (Fig. 

 31); (2) Poecilocyttares, an unsatisfac- 

 tory group of which the chief character- 

 istics appear to be that the nest is always 

 covered by an envelope, and the comb is 

 supported by an object such as the branch 



P T i i ,, , FIG. 32. Nest of (?) Polybia 



of a tree, round, or on, which the envelope 8p _ The envel v ope p / rtly 

 is placed (Fig. 32); (3) Phragmocyttares, 

 in which the layers of comb are supported, 

 in part or entirely, by the envelope of the nest, communication 

 being effected by a hole in each layer of the comb (Fig. 33). 

 de Saussure's classification is far from satisfactory. There are 

 many social wasps that construct nests destitute of any proper 

 envelope ; as an example of this, we may mention the species of 



1 Monographic des gutpes societies, Geneva, 1853-1858, pp. cc. and 356, plates 

 i.-xxxvii. 



VOL. VI G 



cut open ; o, entrance. 

 (After de Saussure.) 



