Threadwaisted Wasp

the ground and provision with grasshoppers. (2) Sphecini (see illus., p. 353): most are slender, and black with base of abdomen orange (Sphex, PI. 16); no teeth on front tarsal claws, both recurrent veins meet 2nd submarginal cell, discoidal vein in HW rises distinctly beyond anterior end of transverse median vein, and abdominal petiole usually is 2-segmented; they nest in the ground and provision with caterpillars. (3) Sceliphronini: 1 tooth on front tarsal claws, both recurrent veins meet 2nd submarginal cell (except Chlorion, blackish with blackish wings), and HW venation as in Ammobiini; most are mud-daubers, making nests of mud and provisioning them with spiders; some of these (Sceliphron, Pl. 16) are brownish with yellow markings and clear wings, others (Chalybion) are blue-black with blackish wings.

Subfamily Nyssoninae. FW with 3 submarginal cells. 1 or

2 (usually 2) apical spurs on middle tibiae. Rather diverse in appearance and habits. Three of the 5 tribes in this subfamily are fairly common. (1) Gorytini (2 apical spurs on middle tibiae, 2nd submarginal cell squarish, propodeum rounded, thorax smooth) are mostly 10—15 mm., and black with yellow markings. The largest species in this tribe is the Cicada Killer, Sphecius speciosus (Drury), which is about 30 mm.; it nests in the ground and provisions its nest with cicadas. Most Gorytini nest in the ground, and provision their nests with various Homoptera. (2) Bembicini, or sand wasps (see also PI. 16), are mostly 20-25 mm., and often have pale greenish markings; labrum is relatively long and triangular. Sand wasps nest in sandy areas, usually in colonies; their nests are sometimes not completely provisioned, and the young are fed as they grow.

(3) Nyssonini (2nd submarginal cell triangular, thorax coarsely punctate, and propodeum angled or spined) are inquilines, laying their eggs in nests of other wasps. The remaining tribes in this subfamily (not illus.), which are much less common, are the

(4) Stizini (basal vein far toward wing base from stigma) and

(5) Alyssonini (2nd submarginal cell triangular, and apex of hind femur produced into a process extending over base of tibia).

Subfamily Mellininae (not illus.). Similar to Nyssoninae, but no recurrent veins meet 2nd submarginal cell. Nest in the ground and provision with flies. A small group, widely distributed but uncommon.

Subfamily Philanthinae. Medium-sized, mostly 12-18 mm., black with yellow markings. 1 apical spur on middle tibiae.

3 submarginal cells. A constriction between 1st and 2nd abdominal segments. Nest in ground. Philanthini have 2nd sub-marginal cell squarish and clypeus extended upward; most provision their nest with bees. Cercerini have 2nd submarginal cell triangular, and provision their nests with various types of beetles (chiefly snout beetles).

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