Megachilids are mostly active in summer and fall, and they hold the distinction as the only bee family in which females carry pollen in a thick brush of hairs beneath the abdomen. In addition, megachilids exhibit a staggering array of nesting strategies, including both above- and below-ground nests, free-standing nests carefully molded out of tree resin, and nests lined with materials as varied as leaves, mud, pebbles, plant trichomes, petals, sap, and even plastic bags.
Exotic bees in our region are mainly above-ground nesting megachilids. Some have been introduced intentionally, since nesting in pre-existing cavities is a trait that is desirable in a managed crop pollinator. Others have been introduced accidentally, since above-ground nests are easily transported across borders in timber exports.
