Understanding the Life Cycle of Native Bees

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Understanding the Life Cycle of Native Bees

Most people know that the honey bee is the most economically important insect in the United States because of the pollination services it provides. "However, some of the native bees like leafcutter bees, carpenter bees and digger bees don't get the credit they deserve for contributions they make to our gardens and food crops," states University of Illinois Extension-Livingston, McLean and Woodford Horticulture Educator, Kelly Allsup. Unlike non-native honey bees, the majority of the native bees is solitary living in the ground or the pith of stems and is most likely not to sting because they do not need to defend the social colony. "An understanding of the life cycle of some of these solitary bees will help you be able to use their services in flower and vegetable gardens this spring," states Allsup.

Most leafcutter bees are black or gray and smaller than a honey bee that is amber colored. These bees construct their nests in existing hollow cavities found in nature or may excavate a hole in rotten logs or twigs of plants like roses. The female constructs a series of cells using oval to semi-circular pieces of leaf tissue to separate her chambers. Damage is not usually noticed, but these leaf cutting bees prefer foliage from rose, lilac, ash, sassafras and Virginia creeper. She then leaves a mix of pollen and nectar paste as a provision for her growing larvae.

The leafcutter bee, known as the mason bee or blue orchard bee, uses mud as the primary construction material. Many orchardist and gardeners can drill holes in wood or provide prefabricated mason bees nests consisting of long, hollow tubes. These bees will find existing cavities to construct their nests. The larvae will overwinter and pupate in the spring. Those who culture (raise) these bees will bring the nests inside to ensure survival throughout the larval and pupal stage. Adults emerge for only a short period of time in the late spring and summer to collect pollen and rear young.

Carpenter bees have the reputation as a nuisance insect because of their wood-boring activities on unpainted wood surfaces. The larger carpenter bees will nest in solid wood and the smaller ones will nest in hollowed-out stems of plants like roses, sumac and elder. The larger carpenter bees are usually yellow and black and can resemble, or be the same size, as a bumble bee. The smaller carpenter bees are dark with a metallic sheen. Male bees do not sting but buzz you to deter you away from the nest. The young adults will hibernate in nests over winter. Starting in spring, the newly mated females will either excavate a new tunnel or clean out old ones dividing the cells with stock piles of pollen and nectar and lay eggs. These eggs will be adults in August and be ready to overwinter.

Digger bees are solitary bees that stock underground nests dug in the soil with pollen and nectar. They can appear to live in colonies because they are attracted to certain soil types, drainage and slope. The female will line her cells with an oily substance to keep it waterproof. The larvae winter and pupate in the spring and early summer emerging for a short period.

To encourage these great pollinating bees to your flower and vegetable garden limit or eliminate pesticide use, plant natives that have long bloom times, create habitats that may be out of the elements such as a wood pile and provide many layers consisting of shrubs, perennials, ground covers and small flowering trees to your garden. Please visit the beespotter.org for more information on Illinois native bees or www.illinoiswildflowers.info for more information on Illinois native bloomers.


Photos Carpenter Bee (Alex wild)

Digger Bee (Phil Nixon)

Carpenter Bee (Phil Nixon)

Mason Bee (USDA)