HYMENOPTERA. 597 



by a sting in a median apodal body segment. Pompilug viaticus L., Anunophila 

 sdbulosa L., Crabro cribarius L. 



Fam. Vespidae* (Wasps). Body slender, smooth. Anterior wings are 

 narrow and can be folded together longitudinally. They are sometimes solitary, 

 sometimes they live in societies ; in the last case the workers also are winged. 

 The females of the solitary wasps build their brood-cells in sand or on the 

 stalks of plants with sand and clay, and fill them rarely with honey, usually 

 with insects, especially caterpillars and spiders ; they thus approach the Fossoria 

 in their mode of life. The social wasps approximate to bees in the organization 

 of their society. They construct their nests of gnawed wood, which they 

 manufacture into lamella resembling paper, and fasten together into regularly 

 hexagonal cells. The combs, which are composed of a simple layer of cells 

 attached to one another, are either suspended freely on the branches of trees, 

 or in holes in the earth and in hollow trees, or surrounded by a common 

 leafy investment, on the under surface of which the holes for exit are placed. 

 In the latter case the internal structure frequently consists of several horizon- 

 tally-suspended combs which are placed one above the other, like the floors 

 of a house, and are connected by buttresses. The openings of the hexagonal 

 vertically placed cells look downwards. The foundation of each wasp nest is 

 laid in the spring by a single female, which was fertilized in the preceding 

 autumn and has survived the winter. She begets, in the course of the spring 

 and summer, workers, which help to increase the size of the nest and to rear 

 the offspring, and of which the larger forms produced in the summer not 

 rarely lay eggs, which develop parthenogenetically into males. The larvte 

 are fed with insects which have been well chewed, and are transformed in a 

 delicate case into pupae in the closed cells. The perfect insects feed as a 

 rule on sweet substances and honey juices, which they are said occasionally to 

 gather in (Polities'). Males and females first appear in late summer and 

 copulate in the flight high up in the air. The males soon die and the whole 

 colony is generally dissolved in the autumn ; the fertilized females, on the 

 other hand, survive the winter under stones and moss in order to found new 

 societies in the following year. Odynerus parictum L., Polistes gallica L. 

 Nests are without investment of leaves and consist of a stalked comb. The 

 fertilized females, which have survived the winter, produce according to v. 

 Siebold at first only female offspring, whose eggs remain unfertilized and 

 develop parthenogenetically into males. Vespa crabro L., hornets. V. 

 vtdgaris L. 



Fam. Apidaef (Bees). Tibia and tarsus, especially of the hind legs, broadened ; 

 the first tarsal joint, especially of the hinder legs, covered with hairs like a 

 brush. Anterior wings cannot be folded together. Body hairy. The hairs on 

 the hind legs or on the belly serve as a collecting apparatus for the pollen. 

 The labium and maxillae often reach a very considerable length. The latter 

 are applied as a sheath to the tongue, and bear only rudimentary palps. The 

 bees are solitary and social, and place their nests in walls, under earth and in 

 hollow trees, and feed their larvae with honey and pollen. Some do not build 

 nests, but lay their eggs in the filled cells of other bees (parasitic bees). 

 Andrcna cineraria L., Dasypoda Mrtipes Fabr., Nomada ruficornis Kirb., 



* H. de Saussure, " Etudes sur la famille des Vespidcs." 3 vols. Paris, 1852 

 to 1857. 



f F. Tlubcr, " Nouvellcs observations sur les Abcillcs." 2 vols. Paris, 1811. 



