It’s simple. Those orange bugs on your milkweed are milkweed bugs! And these little fellas (or gals) above are one of the later-stage nymphs of the insect.
Milkweed bugs come in two versions. Large Milkweed Bugs (Oncopeltus fasciatus) and Small Milkweed Bugs (Lygaeus kalmii), both of which feed on the seeds of milkweed plants. You can see them above clustering on what might be the pods of tropical milkweed (Ascelpias curassavica) this week at the Toronto Botanical Garden.
Apparently, there’s also a very similar-looking False Milkweed Bug (Lygaeus turcicus) that prefers the seed of false sunflower (Heliopsis helianthoides). And the Eastern and, to some degree, Western Boxelder Bugs (Boisea spp.) look similar, too.
This fact sheet from the University of Wisconsin tells you all about these rather decorative creatures. According to the Missouri Botanical Garden, these sucking insects are “more a nuisance than a threat.”
In fact, when I nabbed a passing TBG staffer to help me ID these on Tuesday, they first thought I was talking about the plant, and said it was invasive. A few seeds lost to sucking insects might not be so bad. So perhaps they’re doing gardeners a favour by noshing on the tropical milkweed, which has also come into disfavour in Monarch butterfly-friendly circles. The current thinking is that we should only grow milkweed that is native to our area.
Don’t want them on your milkweed? The easiest thing is to knock them off the plant into some soapy water. They’re pretty slow moving and their colour makes them easy to spot.