Carder Bees and Lambs Ear

The quest to find the European wool carder bee (Anthidium manicatum) will lead you straight to the nearest patch of lambs ear (Stachys byzantina). The male bees can be found aggressively patrolling and guarding their territory against other carder bees and unsuspecting intruders.  Carder bees can be easily confused with yellow jackets due to distinctive yellow markings on their abdomens albeit they are significantly hairier. Unlike most other bee species male carders are larger than the females a perfect example that nature is riddled with exceptions. Male bees do not have stingers but male carder bees do have five sharpe spurs on the tip of their abdomen that can fatally wound other bees that might trespass within their realm. 

Within the “zone of protection” females are free to gather nesting material using their toothed mandibles to shred fibers from lambs ear and other similar plants. This shredding behavior mimics the wool carding process that involves separating and straightening sheep’s wool with two brushes so that it cane spun into yarn. The female bees form this carded material into little cotton like balls they use in the nest as divisions between brood cells. Mason bees use mud to partition brood cells while leaf cutter bees use cut leaves for the same purpose. Like the majority of bee species, they are solitary bees and every female seeks out her own nesting chamber in a hollow stem or tube. In this nest she lays her own eggs and provisions them with bee bread, a mixture of pollen and nectar. Interestingly, Carder bees collect pollen on hairs on the underside of their abdomen. This is defining characteristic for all bees in the Megachile family. Typically we think of bees gathering pollen on their rear legs. 

There are two types of Wool Carder Bees.  This is Anthidium Oblongatum  on purple toadflax

Lambs ear is a plant with elongated oval leaves covered in a wooly peach fuzz reminiscent of a baby lambs ear. Lambs ear and carder bees share an evolutionary history. The plant is native to Turkey and Iran which overlaps the native range of the bees.  The plant arrived in America first and was planted in colonial medicine gardens such as the Kings Garden at Fort Ticonderoga.  The plant was used as field dressing for wounds incurred on the battlefield.  It has antiseptic, anti-inflammatory and antibacterial and absorbent properties making it an ideal bandage.  It certainly was an indispensable plant in its day.  Today, it is a valued ornamental.  The European Wool Carder bee is the most widely distributed unmanaged bee in the world and was first found in the United States in the 1963 near Ithaca, NY and since has expanded its range all the way to the West coast.  The bees are found throughout the world having expanded it range into South America, apparently following behind the range expansion of lambs ear. 

A daring honey bee on lambs ear

Carder bees though they rely on lambs ear for nesting material will also visit mullein (Verbascum thapsus) and rose campion (Silene coronaria) for the same purpose.  Carder bees are generalist pollinators and will visit a variety of flowers for pollen and nectar.   They are attracted to purple toadflax (Linaria purpurea) and hedge woundwort (Stachys sylvatica).  All the plants listed here are native to Europe, western and Central Asia, the native range of the carder bee.  It is interesting to speculate that non-native bees prefer the non-native plants of their homelands over native plants of North America. Is the reverse true, do native bees prefer native plants over invasive plants? Or rather do invasive and/or on-native plants disrupt native flower and native pollinator relationships?  If so, invasive species outcompete native plants forcing native bees to adapt to the new plants in order to survive.     


Female wool carder bee

Carder bees have been able to expand their range along with their preferred plants.  Though lambs ear is a mint it does not have invasive tendencies like other mints.  Carder bees could be considered an invasive species.  It attacks and even kills other native bees and potentially has a localized effect in reducing their populations. The good news is that the carders limiting factor is the localized nature of lambs ear and other similar plants to urban or suburban areas.  Is the  control of carder bee populations  as simple as controlling lambs ear populations?  Probably not but the carder bee and the lambs ear are two species uniquely designed for one another and aptly named. 

Male wool carder bee are larger than the females