Orchid bees are among the most brilliantly colored insects. A lot of species are green, blue, purple, gold, or red. Some are black with yellow or white hairs and resemble bumble bees, to which they are closely related. Orchid bees range from 8 to 30 mm (0.3 to 1.2 in) long. They’ve tongues that, in some species, could be twice as long as the body. The long tongue authorizes them to reach nectar in deep-throated tropical flowers.
Orchid bees are fast, strong fliers and can travel excellent distances. Some are known to fly as far as 45 to 50 km (28 to 31 mi) in search of flowers. Orchid bees drink nectar for energy.
Male orchid bees are especially attracted to orchids, from which they collect fragrant oils that are stored in specialized receptacles on the hind legs. The orchids often produce no nectar or pollen, but they have special mechanisms that attach the pollinium, or pollen bundle, to a specific location on the bee as it gathers oils or searches for nectar. The pollinium releases its pollen on the next flower of the same species that the bee visits.
Males of some species are easy to observe because they are able to be attracted to artificial fragrances. Females are less attracted and as a result less frequently seen.
Orchid bees display very intriguing foraging behaviors and are believed to be important pollinators of many tropical plants. Plants in the tropics don’t grow in groups, and individual plants of the same species are often miles apart. Orchid bees are believed to forage on specific plants along set routes, a behavior known as traplining.
The nests of only several orchid bee species have been found. Nests are constructed in cavities in wood, in fern roots, in the ground, in bamboo stems, in termite nests, under palm leaves, in crevices, under bridges on rocks, and on roofs of houses. Nests are lined with resin accumulated by the female. Some species seal up the nest entrance with resin at night.
Some nests are constructed of wood chips or bark mixed with resin. A lot of species nest in groups. Some nests are shared by a number of individuals, but each female constructs her own brood cells (compartments for the young) independently. Nests may be used continuously by different generations of orchid bees.
Orchid bees in one genus have lost the ability to make their own nests. Instead, they parasitize the nests of other orchid bees. Other types of insects also parasitize the nests of orchid bees. These insects include velvet ants, blister beetles, and other types of parasitic bees.