Anthidium florentinum, one of several European wool carder bees, is a territorial species of bee in the family Megachilidae, the leaf-cutter, carder, or mason bees.
The species is a medium to large bee. Both sexes have a black abdomen bearing two yellow bands on each tergite. The male can be distinguished by the grey and or whitish hairs on the sides of the abdomen. Females are smaller than males and have pale yellowish pollen brushes on the underside of the abdomen. The nest is made in a crevice or the abandoned nest of another insect and is lined with chewed plant fibres.
Global Spread: Native to parts of Europe, Africa, and Asia, they have been accidentally introduced to North and South America, New Zealand, and the Canary Islands, becoming widely distributed globally. In these non-native areas, they are considered an invasive species, though they have not been found to have significant negative impacts on native bee populations or agriculture in most cases.
In both A. florentinum in southern France and A. manicatum in southern Germany, unlike the majority of solitary bees, a study found that there are more females than males, males are bigger than the females, and the sexes fly at the same times of year. P. Wirtz and colleagues suggest that this pattern is explained by the prolonged sexual receptivity of the females, along with the males' use of readily defended resources in their territories.
A. florentinum obtained from Iran was found to be a more efficient pollinator of alfalfa in the United States than native species.
Name Origin: The common name comes from the female's behavior of scraping, or "carding," soft hairs (trichomes) from the leaves and stems of fuzzy plants (such as lamb's ear) using her mandibles. She rolls these fibers into a ball to line and partition the individual cells of her nest.
Solitary Nature: These bees are solitary, meaning they do not live in colonies or hives with worker bees. Each female builds and provisions her own nest in existing cavities, such as hollow plant stems, abandoned beetle holes, or cracks in walls.
Appearance: Both sexes have a black body with distinct yellow markings or spots on their face and abdomen. Males are unusually larger than females, which is uncommon among most bee species.
Male Territoriality: Males are highly aggressive and fiercely territorial, defending patches of flowers to monopolize access to females that visit those flowers for food. They will chase away other insects, including honey bees and even bumble bees, and use five sharp spikes on their abdomen to fight rivals.
Sting and Safety: Only female bees have a stinger, which they use for defense but are not typically aggressive towards humans unless handled or threatened. Males do not have stingers, making them harmless to people despite their aggressive displays.
Pollination: They are generalist pollinators, visiting a variety of plants for nectar and pollen, but show a preference for flowers in the mint family (Lamiaceae).
