One of the most interesting groups of insects, ideal for student projects during a fieldcourse in the American tropics, is the Orchid Bees (Apidae: Euglossini). These are beautiful bees of which most species have metallic iridescent colour of various hues of green, blue or bronze, although there are hairy and black groups. Other conspicuous features of these bees are the long tongue, which is often longer than the body length, and the remarkably swollen hind tibia of the males. Male orchid bees play a key role in orchid pollinations, this is why their name. There are 66 recorded species of orchid bees in Costa Rica, of about 200 species known worldwide.
Male orchid bees can easily be lured with odour baits, for instance, clove or eucalyptus oils, and thus be closely observed by a student. Here are a couple of photos and two short videos showing the males of Euglossa bees in action.
Another interesting group of bees commonly seen in tropical America is the Stingless Bees (Apidae: Meliponini). These are close relatives of the Orchid Bees, but highly eusocial – in other words, living in large family groups (up to 100,000 adult individuals depending on a species) containing two main casts: a queen laying eggs and her daughters, the workers that cooperate in rearing the brood and maintaining the nest; exactly as it happens in the hives of the well-known Honey Bee (Apis mellifera). Many regional hotels in Costa Rica have special feeders set up for hummingbirds so than visitors can observe them virtually from the windows of their rooms or from hotel balconies. The same feeders, which are filled with sweet nectar-like liquid, also attract lots of Stingless Bees. On the following photos and a short video below you can see and watch a group of Trigona bees, apparently of the species Trigona corvina, observed on a hummingbird feeder near the hotel ‘Rancho Naturalista’ in Turialba region of Costa Rica. The second image and video shows the Stingless Bees of an unknown species near their nest at La Selva Biological Station in Costa Rica.