Stewards of the Northwoods: Summer of the Lonely Milkweed

By Licia Johnson, Naturalist

We saw our first Monarch butterfly here at the Discovery Center on May 31^st. Almost every day since then, we have been checking the milkweed (the only host plant of the Monarch larva) in search of eggs and caterpillars. The flowers on the plants are starting to bloom and we have yet to find a single egg or caterpillar. In summers past, at this point we usually have no fewer than 50 Monarchs being reared in our Nature Nook. This year we have some pretty lonely milkweed. I’ve talked with other naturalists around the state and they are seeing the same trend.

So where are all the Monarchs?

We have seen fewer butterflies this year than any other. Sadly we are not alone, all states surrounding Wisconsin are also reporting low numbers of butterflies. As a monarch enthusiast, the lack of all stages of Monarchs has me greatly concerned. Looking into it a bit more, there are several factors at play in explaining these low numbers:

· The overwintering population of Monarchs in Mexico in 2012-2013 was at an all-time low- only 1.19 hectares. This number of butterflies defines the upper-most limit of butterflies that will be returning north to southern US in the spring.

· Our hot, dry summers. Locations in a drought, having hot, dry weather, tend to shorten the lifespan of the adult Monarch butterfly. In turn, they produce less eggs, and thus, less butterflies.

· Deforestation of the Oyamel fir forests-the only forests Monarchs travel to in the winter time down in Mexico. The loss of over-wintering habitat is a very important factor, including many of our neo-migratory birds.

· Changing in crops and farm practices. Many of the milkweed plants that used to grow in fields are being eliminated.

· Landscaping that contains nonnative species.

· Use of pesticides. This kills larvae and adult caterpillars, along with the intended insect target.

· Loss of habitat. As roadsides are mowed down, fields of milkweeds cleared for development, the amount of habitat for these animals is quickly diminishing.

What Can You Do?

There are some factors at play here that are hard for us to interject and correct, but there are many things you can do to help our Monarch friends (and easy too!):

· Plant milkweed in gardens and around your house- they have a beautiful flower that smells just like lilacs!

· Encourage others to plant milkweed.

· Plant native flowers as food sources for all butterflies.

· Don’t use pesticides or herbicides in gardens and areas where butterflies are found.

· Rear monarch larvae into the adult stage and become part of a monitoring effort that tags them in the fall to contribute to important migration and population information.

Please feel free to contact me, Licia Johnson licia@discoverycenter.net if you have any questions about our Monarch population and how you can help them. Monarch conservation and habitat restoration will be key in the coming years to ensure a healthy population of Monarch butterflies.