Question regarding the status of butterflies and the Hercules beetle in MD....

Asked July 19, 2018, 4:08 PM EDT

I've noticed this year, there are hardly any butterflies....anywhere. I have an organic flower garden with flowers that attract butterflies, but I have only seen one Tiger Swallowtail, two Monarchs and a few white cabbage butterflies. Is this due to climate change, destruction of habitat, some peoples use of Roundup weed killer and neonics...or all of the above? Also, I know that Hercules beetles live off of the sap of Ash trees, but now that our Ash trees are disappearing due to the destructive Emerald Ash borer, will the Hercules beetle become extinct?

Montgomery County Maryland

1 Response

We suspect the butterflies are behind this year in part due to our cool, wet weather this spring. There are several factors that are contributing to the decline of insect populations in general: habitat loss, pesticide use, monocultural plantings and lack of plant diversity for food sources. Even when we include in our gardens plants that are desirable for specific butterflies and other insects, there may not be enough of a larger habitat to support their populations.

While we don't have specific research data from Maryland, there have been other studies on the decline of insects in other locations around the world. These are noted in this article from Yale University.

Regarding the Hercules beetle and ash trees, there are some ash trees that are showing resistance to emerald ash borer, and new ash seedlings are regenerating in some places. Some of "lingering" ashes are likely to remain, though the population overall will be much less abundant. The reduction in ash tree availability will have an impact on many species.