Neonics on Milkweed Brings Negative Publicity

Chris Beytes

It’s one thing to use neonics for general pest management, but why would you put them on a plant called “butterfly weed,” which consumers very often buy specifically to attract butterflies to their garden? And why would you do so and then label that plant as having been treated with neonics?

The average consumer may not notice. But when a garden club member spots said plant in her local store, she’ll report it to the local Master Gardeners, and all the local and national Garden Club chapters and members. That’s just what happened down in New Orleans recently, with this garden club member’s alarm being spread to garden clubs all across the country.

Unfortunately, asclepias is prone to every common insect we have, including aphids, thrips, leafminers scale and caterpillars, so a systemic seems like a good solution for battling them. But what about alternatives?
Our resident perennial expert, Paul Pilon, offered some advice on controlling pests on butterfly weed without resorting to systemics. Here’s what he suggested:

In natural predators:

Aphelinus abdominalis—Parasitic wasp
Aphidius colemani—Parasitic wasp
Aphidius erviss—Parasitic wasp
Aphidoletes aphidimyza—Predatory midge
Chrysopa (Green Lacewing)—Predator (lady bugs can also be used)

In biological control agents:

Isaria fumosorosea (Paecilomyces fumosoroseus)—Mycoinsecticide (Preferal)
Beauveria bassiana—Mycoinsecticide (BotaniGard/Mycotrol)
Chromobacterium substugae (Achromocil)—Bioinsecticide (Grandevo)
Azadirachtin—Insect Growth Regulator (Aza-Direct, Azatin, Ornazin)
Potassium salts of fatty acids—Insecticidal soap (M-Pede)

In traditional chemistries*:

Endeavor (pymetrozine) and Aria (flonicamid)—translaminar—lasts about 30 days.
Kontos (spirotetramat)
Avid (abemectin)

*Although effective, these products might not be suitable for asclepias, as they’re translaminar and get into the leaves (provides some residual).

Says Paul, “If I had to spray asclepias for aphids, I’d probably use insecticidal soap mixed with a pyrethroid such as Talstar (bifentrhin) or Decathlon (cyfluthrin). However, this would wipe out beneficials if they are being used.”

We’re not publishing this as strict cultural instructions, but rather to make you aware of the potential problem and let you know there are alternatives. Be sure to follow any label instructions. And check with your pest management expert for firm recommendations. But do try your best not to give our pollinator-loving customers a reason to fear our pollinator-attracting plants. GT