Category Archives: education

New Garden Guests

In the second year of growing common milkweed (Asclepias syriaca), I not only learned more about the plant’s growth habit in a tended garden, but also about the variety of insects it draws. Like many gardeners in the past several years, I expanded my milkweed inventory to supply food and nursery space for the monarch butterfly. Like the swamp milkweed, the common milkweed attracted aphids, then ants, then lady bird beetles and sooty mold. However, this year a new resident arrived.

One day when studying the evolving drama of The Milkweed Diaries, I noticed a new bug. This one wore a pretty flashy palette of reddish-orange and black. Not that subtle. The mouthpiece was a proboscis, which is an indicator the bug feeds on sap.  It also was just chilling toward the top of the plant, not participating in the balance of life being played out between the aphids, ants, and lady bugs on the leaves below. Naturally I grabbed a camera and snapped some photos of the unknown bug to ID it.

It didn’t take too long searching before I found it on The Internets. It is Oncopeltus fasciatus commonly know as the large milkweed bug.  They can be found on milkweed plants in mid to late summer when seedpods are getting ready to form. If you take a closer look at this adult, there is a black band across its body. I used this to ID it as the Large Milkweed bug, instead of the similar looking Lesser Milkweed Bug (Lygaeus kalmii) which has a set of inward facing, orange brackets on its back.

Like the monarch butterfly, milkweed bugs ingest the milkweed plant and therefore accumulate in their bodies cardiac glycosides (cardenolides). These alkaloid toxins are dangerous if ingested by predators.

Unlike Lesser Milkweed Bugs, this guy sticks to the Apocynaceae (dogbane) family when looking for its next meal. Both adults and nymphs feed on milkweed pods and seeds.

Do They Harm Monarchs?

Most gardeners grow plants from the milkweed family with monarchs on the mind. Who wouldn’t love waiting on those lovely butterflies? So, as I was reading about the large milkweed bug, I wondered if it was a natural predator of monarchs.

From what I could find, the Large Milkweed Bug is a vegetarian. However, the Lesser Milkweed Bug will scavenge on insects as a adult, including Monarch larvae. I feel this is just another example of why it is so important to carefully research your garden guest before knocking them into that jar of soapy water.

Should They Stay or Should They Go?

Stay. Both large and lesser milkweed bugs do not oppose an immediate threat to milkweed. The feeding damage is minimal, and the bug’s life cycle and overall presence in the garden is short. They are one of its many pollinators. Booming populations on a plant may be an indicator of a plant that is otherwise stressed or lacking something it needs to grow.

References

Ohio State University Extension

Milkweed: Not Just for Monarchs

Michigan State University Extension

Missouri Botanical Garden

WTF – Black Bindweed

I feel this garden season has been packed with plant identification. In no way am I complaining about this. Plant identification is a pretty enjoyable game to me. When a fellow gardener was telling me about a swift-growing vine with heart-shaped leaves in her home garden, I fought the urge to immediately hiss “bindweed” (Convolvulus arvensis). The weed is from the Morning Glory (Convolvulaceae) family and is a complete terror on the Lot. I agreed to make a visit to help with some pruning, so I pretty much had to find out if I was right or not.

Analyzing the Offender

When I arrived and was able to meet the vine in person, I realized it wasn’t bindweed. I would recognize my Nemesis anywhere, in any growing zone, and this wasn’t it. Yes, the vine was eating the porch alive and the leaves were heart-shaped. However, I immediately noticed what looked like white seed heads in large clusters all along the vine… not a trait of the bindweed we deal with on the Lot.

Black Bindweed covering Lantern

There aren’t many weedy vines in our state, so I started going through some weed ID sites looking for the vine that would be going to seed at this time of the season. Eventually I found a site for a project at the University of Michigan: Burnham, R.J. (2008-2014). “CLIMBERS: Censusing Lianas in Mesic Biomes of Eastern RegionS.” (September 6, 2017).  And that is where I found the name of the plant I was looking for: Black Bindweed (Fallopia convolvulus) of the Buckwheat (Polygonaceae) family.

Up Close and Personal

When ID’ing a plant, there are a lot of clues one can pick up by taking a thorough look at the specimen. Parts of the black bindweed helping me to ID it were:

  • alternate, simple, heart shaped leaves
  • vine, twining from right to left
  • glabrous (free from hair) ocrea (sheath around the stem)
  • roots are non-rhizomatous
  • branching of vine located more near base of plant
  • papery calyx (sepals of the flower)
  • flower understated with no petals

Black Bindweed on Railing

Evicting the Weed

I struggled to find a control method for black bindweed. It’s an  aggressive, annual weed introduced from Eurasia. The plant spreads by prolific reseeding. The seeds themselves are enclosed by a hard shell and can be viable for more than a single season in the soil. In fact, this was the reason my gardener friend inquired about the plant. She said though a crazy climber, the plant was kind of pretty (which it was). But then she saw all the flowers (future seeds) and thought “Oh sh*t.” Yeah, we’ve all done that before.

What we do have on our side when removing this vine is the fibrous root system and the small area of a home garden. Though fairly deep, the roots aren’t a rubbery, rhizomatous system that takes off underground like a berserker gopher. The plant was removed and burned. Next season, the gardener has to keep an eye open in the spring for any new seedlings and pull as needed.

Hey Four Eyes

After a garden fieldtrip to Lake Cliff Garden, we stopped into a neighboring town for lunch and some social time. On the top of a hill near the lakefront, I found this large stand of common milkweed (Asclepias syriaca). Of course I had to go over and see what little critters were enjoying the beautiful, summer day.

Stand of Milkweed

I was not disappointed! One of the insects immediately catching my attention was a colorful, red beetle. I was able to snap a pretty good photo to bring home and use to identify the milkweed resident.

Red Milkweed Beetle on leaf

Red Milkweed Beetle

The insect is Tetraopes tetrophthalmus or the Red Milkweed Beetle. Like many other insects who feed on milkweed, the beetle’s bright color warns predators it is toxic because it ingests the plant. Larvae burrow underground to feed on the roots and overwinter. Adults emerge to feed on leaves, buds, and flowers of the plant and can be spotted in our growing zone about midsummer.

What’s With the Eyes?

Something interesting I read and then found on my photo, was the position of the beetle’s eyes. Let’s zoom in for a closeup!

Closeup of Milkweed Beetle Head

The Red Milkweed Beetle’s compound eyes are bisected by its antennae. One set of eyes is located above the antennae, while the other is located below. In Latin, both the genus and species name translates to mean “four eyes.”

Purring Bugs?!

Another fascinating fact I stumbled upon while cyberstalking the Red Milkweed Bug is that they vocalize. These bugs squeak and purr! A gentleman by the name of Richard D. Alexander wrote a paper in 1957 titled Sound Production and Associated Behavior in Insects. When observed in the lab, the RMB vocalized when going about its day interacting with the milkweed plant and others of its species. It does so by rubbing together structures on the segments of the thorax. I will definitely be leaning in to take a listen if I’m fortunate enough to spot the Red Milkweed Beetle next season.

But Will They Harm Me or My Plants?

The short answer is “no.” A healthy stand of milkweed will not be harmed. If you’d rather not see the beetles, you can remove the milkweed plant from the garden. As with most creatures, if the beetle is not assaulted and manhandled, it will not bite.

References

Michigan State Extension

College of Letters and Science Field Station – University of Wisconsin Milwaukee