I was recently interviewed by a journalist with PBS who wanted to do a story on the decline of Monarchs. Now, as an entomologist, I will be the first to admit, that while I enjoy collecting and looking at butterflies, they really aren't my favorite insect. And I will certainly admit that I don't know as much about them as I should. So, knowing that I would be questioned on one of my entomological weaknesses, I started doing some research and found Monarchs are really very interesting insects! (That's one thing I love about entomology - just when I think I know it all, I come to realize there is still so much more to learn!)
Nearly all Texans know Monarchs as our state insect and for their beautiful orange and black coloration. However, Monarchs are not found in just Texas. They can be found nearly all over the United States. Monarchs are a migratory butterfly and we tend to find them travelling down from the NE United States into Texas toward their winter hideout in Mexico around September through November. Monarchs cannot make the cold winters up in the northeast, so they make their down to Mexico to spend the winter in warmer temperatures.
When spring comes, they pick up and leave, heading back to the northeast. They arrive, tired, hungry and beat up. Its a long hard trip and they've now done it twice! Amazing! They will lay their eggs on milkweed plants, where their larvae will feed and the life cycle starts again.
Now, not every single Monarch will make this trek. Certainly, there are many who stay in one spot and complete their lifecycle there, but their story isn't as interesting as the migrating Monarchs.
In recent years, it has been well documented that the Monarch populations have been declining. We can see this in Mexico, where they overwinter. I have been told the millions of Monarchs on a single tree in Mexico, fluttering their wings, is a breathtaking thing to see, but I have never seen it in person. It is one of the many things on my bucket list!
In 1997, Monarch populations were at their peak - they occupied 50 acres in Mexico while overwintering. In 2012, they only occupied less than 3 acres. That's a huge decrease!
There are many reasons that have been listed for the decline of Monarchs. Likely all have some impact, but each one combined is causing big problems. I don't think one reason is the main reason. As with all things, there are many variables. Monarch decline has been contributed to anything from increased traffic on highways to deforestation in Mexico to a decrease in milkweed.
What can you do if you love Monarchs? Plant some milkweed! Give them what they want. But also remember that this is only the food source for the larvae. Adults need nectar producing plants, so be sure to plant those in the landscape as well. Those migrating butterflies will need some energy and those that stay in Texas will need a reason to stay!