Where are the butterflies

Asked July 18, 2020, 11:32 AM EDT

By this time of year my garden is full of butterflies. I have only seen one and that was two days ago. Has something happened to the butterflies? Thank you Toni Murphy

Prince George's County Maryland

1 Response

Hello Toni,

The multiple late frosts this year could have played a role in hampering pollinators like butterflies this year - some are more resilient to cold than others once they emerge from winter dormancy. Additionally, predator-prey interactions are at work, where some years populations boom or bust based on how well their predators (or parasitoids) have fared. There are also naturally-occurring pathogens, like insect-infecting fungi, which may have prospered in the wet, cool conditions of this spring's weather (and the past few springs as well). The persistent background pressures of pesticide use, habitat loss, climate change, and introduced pests (both as direct competitors, pathogens, or predators, and indirect as resource destroyers) all play a role in chronic decline of pollinators and other insects.

Late summer (~August) is when our area tends to see a natural peak in butterflies for the season. The adults of Swallowtails are out for their final round of breeding (they spend the winter as a chrysalis), the Buckeyes are at their peak from migration and breeding (they do not overwinter here), the Painted Ladies, American Ladies, and Monarchs are getting ready to migrate and/or squeeze in one last generation (or may already be moving south from more northerly latitudes), and various other butterflies that overwinter as non-adults (Viceroys, Red-Spotted Purples, etc.) are also breeding one last time. They will likely be seen first on their favorite nectar plants, which as a generalization, tend to be those in the Aster, Mint, and Vervain families.

Miri