How do invasive ladybugs harm ecosystems?

Ladybugs pest control activities can generate the opposite effect, or unintended consequences when non-native species of ladybugs become dominant. For example, exploratory research of Asian lady beetles (*Harmonia axyridis*), introduced to manage aphids in trees, has documented that this non-native species has displaced 90% of native ladybugs in the eastern states of the United States. I also have documented fruits in orchards - from invasive lady beetles to Asian lady beetles - that caused more damage than the aphids the lady beetles were presumably managing.

The invasive ladybugs disseminate microsporidia parasites through shared feeding locations. According to a 2023 study by Cornell University, 68% of wild *Coleomegilla maculata* tested positive for microsporidia after subsequent contact with the Asian lady beetles. The fungal parasite decreases the survival rates of native larvae by up to 80%, which is effectively a death sentence for local populations.

The economic costs increase rapidly. Midwestern vineyards indicate annual costs exceeding $12,000 to clean beetles from grape clusters in the fall. Likewise, homeowners report pest control costs of $500 to $2,000 for infestations. Now compare that to a cost of only $50 to set up a native ladybug habitat to help prevent these invasive species naturally.

Combat invasives through the planting of native buffers. Goldenrod and milkweed repel the invasive Asian beetles while drawing in *Hippodamia convergens*. A Michigan blueberry farm decreased the number of invasive swarms by 90% with floral borders and saved an estimated $8,000 in lost yield and cleanup labor costs.

Read the full article: Ladybugs Pest Control: Benefits and Risks