HYMENOPTERA -
Winged insects. With two pairs of wings, or fore wings not membranous. Fore wings and hind wings usually similar in texture and structure. Wings largely transparent or covered with fine hair. Mouthparts not a piercing-sucking beak and normally situated at the front of the head. Antennae conspicuous and of different forms. Wings with few veins and cross veins with larger cells. Tarsi usually five-segmented, fore wings larger than hind wings, abdomen usually constricted at base.
Apocrita -
Base of abdomen constricted, the abdomen petiolate; hind wing with 2 or fewer closed basal cells.
APOIDEA -
Antennae variable: wings fully developed, shortened or absent. Pronotum not reaching back to tegula. Lateral pronotum with a rounded lobe fringed with fine hairs (= spiracle cover lobe), sometimes obscured by dense hairs. First segment of hind tarsus elongate, as long or longer than remaining segments combined, usually thickened and flattened; some body hairs (usually on thorax) branched or plumose; abdomen never petiolate.
APIDAE -
Forewing with 3 submarginal cell. Basal vein of forewing straight or only slightly arched; jugal lobe of hindwing about the same length or shorter than submedian cell. Stigma never longer than half the length of the second submarginal cell.