Wool-carder bee

The Wool-carder bee (scientific name: Anthidium spiniventre) belongs to the order Hymenoptera and the family Megachilidae. Unlike social bees, this species is solitary. It has gained attention in agronomy and gardening due to its habit of scraping hair from plant surfaces to build its nest, which can cause aesthetic and minor physiological damage to various ornamental plants.

The bee typically targets plants with pubescent (hairy) leaves and stems. Common host plants include Salvia, Stachys (lamb's ear), Lavandula, and various rose species. By scraping the plant tissues to collect fiber, the bee leaves behind ragged, bare, or discolored spots, which reduces the visual quality of the foliage and can sometimes cause secondary health issues for the plant.

The life cycle of Anthidium spiniventre consists of egg, larval, pupal, and adult stages. The females spend considerable time foraging for plant fibers. After gathering the material, they transport it to nest sites, which are often found in hollow plant stems, abandoned beetle borings, or narrow crevices. Males are territorial and can be seen patrolling their patches, actively driving away other insects.

Regarding damage, the primary concern is the physical destruction of the epidermal layer of leaves. While individual bees do not usually cause widespread agricultural collapse, heavy infestations in a garden or nursery can lead to a significant decline in plant vigor. The resulting wounds can act as entry points for pathogens, making the plants more susceptible to fungal infections during humid conditions.

Effective management strategies focus on prevention rather than chemical eradication. Because these bees are also important pollinators, pesticides should be avoided. Instead, consider these approaches:

• Cover sensitive plants with protective netting during the peak egg-laying season;
• Remove dry, hollow stalks in the fall that provide nesting cavities;
• Fill cracks in wooden structures that could be used as nest sites.