Although many other organisms besides bees are good at pollinating plants, bees are the only species that carry pollen from one flower to another, a unique evolutionary process. Most people think of the non-native species, European honey bee, when they think of bees, a species introduced to the U.S. in the 1600s. Honey bees are different from our native bees in two ways. First, they are colonial, living in hives, and produce honey. All are in the same genus and species, Apis mellifera.
Pictured first is the Concave Cuckoo Bee (Triepeolis concavus). Cuckoo bees are cleptoparasites, laying their eggs in the cells of their host’s nest. This cuckoo bee, like others in this genus, watches their host gathering pollen and then follows the host back to her nest. Some species in this genus have a smiley face on the thorax making them fairly easy to identify.
The metallic green bee with the yellow and black striped abdomen is one member in the group of sweat bees, although only a couple species are attracted to human sweat. This one, Agapostemon, is a southwestern species nesting in the ground often with a mound of dirt that looks a bit like an anthill. Agapostemon bees are flower generalist but many are frequently found on flowers in the sunflower family.
The third bee pictured is common, a female Megachile parallela looking for nectar on a common sunflower. They often tip their abdomens upward which shows their pollen load. They line their nests with leaves and as such are in a group called leafcutter bees. Females chew leaves until they become gummy, and she then presses multiple gummy leaves into sheets which she uses to line the walls of her nest. One species of Megachile, alfalfa leafcutter bees, have replaced honey bees as alfalfa pollinators and since then alfalfa production dramatically increased by 15x.
The last image shows an Orange-tipped Woodborer (Lithurgopsis apicalis). All bees in Lithurgopsis nest in wood as the common name implies, most often in decayed or rotting wood. They specialize in flowers in the cactus family. Pollen is collected in baskets or scopa, and thus Lithurgopsis are important pollinators of cactus flowers. Cacti, by the way, are considered a keystone species, a species whose importance is greater than its abundance in the ecosystem.
One noticeable bee tribe, the Eucerini, have very long antennae and they are therefore referred to as long-horned bees. This one is in the Melissodes genus and a late summer visitor, often to flowers in the sunflower family; many species bloom in late summer. Melissodes are ground nesters and females sleep in their nests during nighttime hours; however males often huddle together on a stem with as many as 10 to 20 individuals.
Everyone knows a bumble bee and members of the genus Bombus are some of our largest bees. There are fewer than 50 Bombus species in North America. “Bombus,” by the way, is Greek for “a buzzing sound”. Bumble bees practice “buzz pollination” in flowers that evolved to store pollen in stamens in a way salt is stored in a salt shaker. Only when the stamens are tipped and shaken will the pollen fall out which only bumble bees can do. Bumble bees have a “pollen basket” on their hind legs. Hunt’s bumble bee is one of the most common on Chico Basin Ranch. The yellow, orange, orange, yellow, black on their abdomen can be used for identification of this species.