elbowed. HW with a jugal lobe. Venation reduced. Abdomen 6- or 7-segmented.

Bethylids are generally 8 mm. or less and are seldom encountered. Larvae are parasites of other insect larvae, especially Coleoptera and Lepidoptera. A few bethylids will sting. Females of many species are wingless and antlike.

DRYINIDS Family Dryinidae

Identification: Small black insects with a reduced wing venation. Antennae 10-segmented, rising low on face, and not distinctly elbowed. HW with a jugal lobe. Front tarsi of $ often pincerlike.

Dryinids are relatively uncommon insects whose larvae are parasites of planthoppers, leafhoppers, or treehoppers. Most are 5-8 mm. Some species are polyembryonic, with 40 to 60 young developing from a single egg.

TRIGONALIDS Family Trigonalidae

Identification: Stout-bodied, wasplike; usually brightly colored and 10-12 mm. Antennae long, with 16 or more segments. Trochanters 2-segmented, 2nd segment sometimes indistinct. Venation complete. FW with a costal cell. HW without a jugal lobe. Differ from wasps (Scolioidea, Vespoidea, Sphecoidea) in the long many-segmented antennae and from ichneumons by the costal cell in FW.

Trigonalids are relatively rare. Larvae parasitize vespid larvae or caterpillar parasites. Eggs are laid on foliage and hatch when eaten (with the foliage) by a caterpillar. The trigonalid larvae then attack a parasite in the caterpillar, or, if the caterpillar is eaten by a vespid and later regurgitated and fed to its larva, attack the vespid larva.

SCLEROGIBBIDS Family Sclerogibbidae Not illus.

Identification: Similar to Bethylidae (p. 339) but antennae of cf with 23 segments and rising low on face, cf winged, 9 wingless. FW with a small marginal cell and 1 submarginal cell. HW with a closed cell.

One very rare species, known only from the male, has been taken in Arizona. The larva of this species is unknown, but sclerogibbids occurring elsewhere are known to parasitize web-spinners (Embioptera).

Ants and Parasitic Wasps: Superfamily Scolioidea

Pronotum in lateral view variable, more or less squarish to triangular, extending nearly to tegulae. Antennae 12- or 13-segmented (with fewer segments in some ants), distinctly elbowed only in ants. Ovipositor issues from apex of abdomen. Venation usually fairly complete.

The term "wasp" is used in this book (with a few exceptions) for members of the superfamilies Scolioidea (other than ants), Vespoidea, and Sphecoidea. Wasps are Hymenoptera in which the females usually sting, antennae are generally 13-segmented in the male and 12-segmented in the female, trochanters are 1-segmented, and larvae usually feed on animal food. Vespoid and sphecoid wasps (pp. 346, 348) generally build a nest, capture prey and provision the nest with it, and thus might be described as pre-daceous. Scolioid wasps are parasitic, their behavior like that of the parasitic members of the preceding superfamilies; they oviposit in or on the body of a host, then oviposit in other hosts, and make no further provision for their young. Bees (Apoidea, p. 354) differ from wasps in that the young are fed plant rather than animal food.

Scolioid wasps differ from Sphecoidea in the form of the pro-notum (see illus., p. 319); Vespidae differ from Scolioidea in having the 1st discoidal cell of the front wings very long and in folding their wings longitudinally at rest; Pompilidae (p. 346) differ from scolioid wasps in having long legs and a transverse suture on the mesopleura. Females of many scolioid wasps are wingless and antlike; females of vespoid and sphecoid wasps have well-developed wings.

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