From the postings on monarchs and our project to create a monarch waystation, you know we have a fondness for milkweed. We happened to notice this brightly colored bug crawling around on a milkweed blossom and wondered if it was friend or foe.
Aptly named the milkweed bug, it feeds on milkweed sap and seeds. Like monarchs, ingesting the milkweed sap makes the milkweed bug a terrible meal for predators. The chemicals in the sap usually make the predator vomit! And like the monarchs, they use their brightly colored bodies to advertise the warning to potential lunch guests: eat someone else!
Milkweed bugs like to gather in groups and can often be seen on milkweed seed pods where they feast on the seeds and sap. If you notice the seed pods looking deflated or deformed, you’ll know the milkweed bugs have been by for a visit.
Females lay their eggs between the seed pods and can lay up to 30 eggs a day, 2000 eggs during their one-month life span. That’s a lot of milkweed bugs consuming a lot of milkweed seeds!
Now, as to friend or foe, if you’re a rancher and trying to grow grass for your cattle or a farmer raising soybeans, you might like milkweed bugs because they help control the spread of milkweed in your fields.
If you’re a monarch lover, they are definitely a foe as they will chow down on the milkweed seeds limiting next year’s crop for the monarchs. Squishing is an organically sound method of ridding your plants of these beasties. Spraying is not, as you want to keep the milkweed healthy for the monarch caterpillars.
For more information and squishing techniques see a great article on milkweed bugs in My Monarch Guide.