Are Milkweed Bugs a Menace for Monarchs?

Q. Chase in Delaware City writes: "I have a pollinator garden in my back yard that includes milkweed plants. Every year natural predators keep the aphids under control, but around the same time our town fogs for mosquitoes, the aphid population seems to explode. Milkweed bugs also become prevalent at this time. Mike often mentions the use of sharp streams of water to remove pests from the plants and I have found this method works well but I'm looking for other ways to deter pests when I'm NOT in the garden. One neighbor suggested spraying diluted dish soap, another suggested dusting the plants with expired pantry flour. Are these methods effective against milkweed pests?"

A. Let's start a bit off-topic. {quote} "Fogging for mosquitoes" the old-fashioned chemical way can be devastating to the life in your garden by killing the beneficial insects that keep pests like aphids in line MUCH better than chemicals. However, if your community is enlightened and sprays the mosquito-breeding preventor known as BTI, mosquito numbers will be noticeably lower, and your pollinators and other beneficial insects will be unharmed.

Get in touch with your local municipality NOW and see what their plans are for the coming summer. If an old school chemical will be in those sprayers, have professionally made "no spray zone" signs at the ready, using arrows and/or distance measurements (like 'no spray zone next 60 feet") to indicate start and stop points. Be sure to inquire if precise legal language or a permit is required. But if BTI will be in those sprayers, thank those in charge for making the right decision.

Oh, and the wonderful organization Monarch Watch, which provides milkweed seeds, information and lots of other useful and fun stuff sells metal signs that identify your property as a 'Monarch Waystation' for $17 bucks each. Put a few of these up around your property and the sprayers should bow their heads in shame!

And I am happy to report that every state extension Bulletin I checked advocated using sharp sprays of water against aphids and 'milkweed bugs'. Now remember kids--we're not talking about gentle soakings here; 'sharp sprays' are sharp! Use an adjustable nozzle that has multiple settings and choose 'laser beam'. Or turn the single setting on one of those old-school 'fireman hose' nozzles until it delivers a stinging blast. I can't say this enough: Multiple research studies have found SHARP streams of water to be more effective than pesticides in eliminating aphids. And it's emotionally satisfying to see the tiny sap suckers go flying towards their final...shall we say..."destination"?

Do this correctly (cradle the plants with one hand while administering a wicked wad of water with the other) and around 85% of the petite pests will meet their immediate doom. The others will be too depressed to go on. Fun for the entire family! Put on bathing suits and spray away!

Now, about those {quote} 'milkweed bugs' that show up mid-to-late in the season. They are incredibly distinctive in their orange and black raiment, with the elongated adults having two black kind-of-triangles at the heinie and head and a black stripe across the middle of their back, interposed with a charming shade of orange. The nymphs (these bugs seem to go through as many instars as Diana Ross does costume changes) are similar in color but are shaped more like a ladybug. Look it up: OK?

They are true bugs in the world of entomology, and there are two versions, defined the same way as a Philadelphia hoagie: small and large. The {quote} "lesser milkweed bug" is similar to the large milkweed bug, but smaller (d'uh!) and less stylishly adorned. In any case, this reporter feels that they could have been blessed with a more helpful common name, like "milkweed SEED bug", because, like the beloved conifer seed bug that likes to sleep inside your house in the winter, these are SEED eaters that do not ravage other plant parts. That's why they appear late in the season, because as Willy Loman famously said, "that's where the seeds are."

All seriousness aside, this addition of a descriptive middle name would help growers of milkweed not to freak out when The Bugs appear in large numbers on their milkweed plants. They're only there for the seeds, and have no effect on Monarch caterpillars, chrysalises, or adults. In fact, say the experts, they perform a valuable function, as some varieties of milkweed can easily become invasive. Milkweed bugs eating most of those seeds helps normalize the situation and allows the plants to 'gently' self-seed, while preventing your stand of milkweed from becoming the new Day of the Triffids. (Gee. Trust Nature to strike a balance. Where have I heard that before? Hummmm...)

To sum up. Milkweed plants provide the only known food for baby Monarchs, and everyone should be planting milkweed. Milkweed SEED bugs do not interfere with the process and may well prevent your garden from turning into a milkweed farm. Seeing lots of the colorful bugs does NOT indicate a problem. As with many such issues, all you need to do is let Nature take its course.

Next week: We look at the different types of milkweed to see which one is best for you.

https://content.ces.ncsu.edu/milkweed-bug

https://www.missouribotanicalgarden.org/gardens-gardening/your-garden/help-for-the-home-gardener/advice-tips-resources/pests-and-problems/insects/plant-bugs/milkweed-bugs.aspx

https://bygl.osu.edu/node/544