The Leafcutter Bee (Megachile spp.) is black with pale hair bands on abdomen; females with orange-yellow pollen on underside and typically measures ⅓–½ inch. Leafcutter bees are solitary native bees in the genus Megachile, with dozens of species occurring across Arizona. They are named for their distinctive behavior of cutting precise, semicircular or circ.

The Leafcutter Bee is generally low-risk, but caution is still advised. Cosmetic leaf damage to ornamental plants. Essentially no sting risk — females are non-aggressive and rarely sting unless directly handled. No structural damage.

In Arizona, leafcutter bees are most often encountered in the following situations: Circular or semicircular holes cut from the edges of leaves — particularly roses, bougainvillea, and ash trees. Smooth, clean cuts (not ragged like caterpillar feeding). Bees carrying leaf pieces in flight. Nesting activity in hollow stems or wood cavities.

The Leafcutter Bee is most active during: Spring through fall; most active May–August in Arizona. Arizona's warm desert climate can extend activity periods compared to other states, so year-round vigilance is recommended in the Phoenix metro and surrounding areas.

Leaf cutting is largely unavoidable and does not harm plants. Row covers can protect high-value ornamentals during peak nesting season. Providing bee houses may redirect nesting away from structures.

No treatment recommended — leafcutter bees are beneficial native pollinators. Leaf damage is cosmetic only. If nesting in an unwanted location, block the cavity entrance after the nesting season ends (fall/winter).

If you are seeing leafcutter bees repeatedly, finding evidence of an established population, or if DIY treatments have not resolved the issue within a week or two, it is time to call a professional. Pest Control Bros offers free inspections and same-week service across the Phoenix metro area — no contracts required.