Velvet ant

The velvet ant (genus Mutilla) is a member of the Mutillidae family within the order Hymenoptera. Despite their name, they are not ants but wingless wasps. Females are flightless, densely covered in hair, and possess a highly potent, painful sting, while males are winged and primarily nectar-feeders.

In the context of agriculture, the velvet ant is considered a nuisance pest rather than a direct threat to plant tissue. Their primary negative impact is the destruction of beneficial insect populations, specifically bumblebees and solitary ground-nesting bees, which serve as essential pollinators for a wide variety of fruit, vegetable, and seed crops.

The life cycle of the Mutilla is strictly parasitic. The female velvet ant locates the underground nest of a host species, often a bumblebee or solitary bee. She enters the burrow, invades the brood cells, and deposits an egg on the host larva. The emerging velvet ant larva feeds externally on the host, causing its eventual death and preventing the development of the next generation of pollinators.

The economic harm caused by these insects is indirect but significant. As pollinators are essential for high-yield fruit production and seed development, the loss of bumblebee colonies due to high rates of velvet ant parasitism can lead to reduced harvest yields and poor plant fertilization. Furthermore, their stings pose a health hazard to agricultural workers and residents.

Integrated management strategies to mitigate their impact include:

• Maintaining clear, groomed areas in the garden to reduce the number of suitable, undisturbed ground burrows for parasite access.
• Avoiding the use of broad-spectrum pesticides, which can exacerbate the imbalance between hosts and parasitoids.
• Physical monitoring of nesting areas during early spring to detect high concentrations of parasitic activity.
• Promoting healthy soil management practices that favor established pollinator nesting while minimizing sheltered spots for velvet ants.