HYMENOPTERA PETIOLATA. 



769 



off ; labrum small. The well-known genus Tachytes has habits very 



similar to those of Sphex, some species preying on Mantis. Larra 



stores up mole-crickets ; others grass-hoppers. 



Sub-fam. 4. Trypoxyloninae. Marginal cell not appencliculate ; 



eyes concave on inner surface. Trypoxylon builds clay nests often 



near human dwellings, and stores them with spiders ; the second 



genus is Pison. 



Sub-fam. 5. Astatinae. The eyes in the male meet in the middle 



dorsal line ; two spurs on the second tibiae. This sub-family has 



but one genus Astata (some authorities however add Oxybelus). Two 



.species are British, one of which provisions its underground cell with 



the Hemipteron Pentatoma. 



Sub-fam. 6. Bembecinae. Marginal cell not appendiculate ; 



nervures nearly reach to edge of wing ; no pedicel ; abdomen heavy ; 



labrum often elongated. The members of the genus Bembex (Fig. 500) 



feed their young mainly on Diptera, which they kill and carry to 



their cells between their legs. As the insects are killed, they must 



frequently be replaced by 



new victims, and the parent 



is kept busy supplying the 



young with fresh food. For 



the most part the cells are 



formed in sandy banks and 



the entrance is blocked ex- 

 cept when in use. 



Sub-fam. 7. Nyssoninae. 



Labrum short ; no pedicel ; 

 marginal cells not appen- 

 diculate. An ill-defined 

 group, many of its mem- 

 bers having a divided tro- 

 chanter something like 

 that of the Parasitica. 

 Mellinus catches flies, feigning death as it lies in wait for them. 



Sub-fam. 8. Philanthinae. Three complete sub-marginal cells on 

 anterior wing ; labrum not elongate ; anterior part of abdomen 

 constricted but without a slender pedicel. Wasp-like Fossores. 

 Cerceris stores paralysed small bees and beetles, and the different 

 species attack different forms of Coleoptera. Philanthus kills honey- 

 bees both for its own food and that of the larvae, which are carefully 

 fed at intervals with fresn food. 



Sub-fam. 9. Mimesinae. A non-cylindrical pedicel present ; one 

 spur on the second tibiae ; marginal cells two or three. This family 

 (including the Pemphredoninae) comprises a few not very well known 

 insects. Psen and Passaloecus make their cells in hollow stems, 

 Pemphredon lugubrit in decayed beech wood. They store up Psyllidae 

 and Aphidae. 



Sub-fam. 10. Crabroninae. One sub-marginal and two discoidal 

 cells ; abdomen rarely pedicellate ; pronotum short. These are 

 small, rather wasp-like insects with large, square heads. They are 

 the commonest of our digging-wasps, Crabro having over thirty 

 British species. They mostly form their cells in dead wood or in. 

 stems, and store them with Diptera. 



Z III 3 D 



FIG. 500. Bembex ros'rnta 

 Sharp. 



Europe. From 



