Why did I have way less monarch caterpillars on my milkweed this year?

Asked September 26, 2019, 7:59 PM EDT

I have a large patch of milkweed. Last year I had at least 30 monarch caterpillars. This year, maybe 10:( Why such a depressing shift? Any ideas?

Baltimore County Maryland beneficial insects and pollinators

1 Response

Hi - Populations of Monarchs, like those of other insects, may be influenced by habitat loss and limited food availability, pesticide use, and climate change. Here is just one study that looks at the decline of insects and the factors involved. https://www.sciencedirect.com/science/article/pii/S0006320718313636

This page provides information on some of the threats to Monarchs in particular.
https://monarchjointventure.org/monarch-biology/threats

This page includes information on what you can do.
https://monarchjointventure.org/

It is also worth noting that there seemed to be an increase in Eastern Tiger Swallowtail butterfly populations this year. Populations can fluctuate from year to year because of weather conditions, breeding success, presence (or lack) of predators and other factors.

Keep growing native milkweeds. Every effort can help.

Christa