Creeping Jenny Eaten By Sawfly Larvae

What's eating my Creeping Jenny?

Golden Creeping Jenny (Lysimachia nummularia 'Aurea'), is a staple in any garden. Used as a perennial ground cover or trailer for containers and hanging baskets - it grows in sun or shade.

So when I walked through the garden this morning, something was awry. I noticed foliage had been eaten; nearly every leaf was damaged.

On closer inspection, these Monostegia abdominalis larvae were happily munching away. Grrrr.

Great, here's another alien insect, reeking havoc in Ontario. Another introduction from Europe we don't need.

These "caterpillars" are in fact sawfly larvae.  Check out this link by Kansas State University to see the difference.

In total, I collected 23 from this one spot.

They are known to feed on foliage within the Loosestrife family of plants, which Creeping Jenny Lysimachia is classified under.

No spraying necessary, it took me no more than 4 minutes to gather them. They are quite easy to find as their silver/grey coating is a great contrast to the lime green foliage. Do Note: once you touch them, they coil and drop off the leaves.  They are known to have 2-3 life cycles per season. These came out in late June, so keep checking your plants for any other generation that may come 'calling'!

One bonus, they became a great snack for our Koi fish in the pond.

Here's Wikipedia's taxonomy description:  Monostegia abdominalis

What's eating my rose, this time?

Lack of rain this June has made our roses suffer. Having chosen Rosa glauca for its drought tolerance, the heat these past few weeks has stressed the bush inviting so many pesky insect issues.

Two weeks ago, I dealt with the Rose Plume Moth eating the flower buds and now I see this:

More webbing and another green larvae. This one skeletonized older leaves and punched holes in new leaf growth.

Ah-ha...here's another "caterpillar" that folks know to feed off roses.

This is in fact not a caterpillar, but a Rose-slug Sawfly Larvae (Edelomyia aethiops). So you say: what is the difference and who cares?

There is a BIG difference.

I learned in school: the Sawflies Larvae have enough prolegs to spell S-A-W-F-L-Y (6 or even more). Caterpillars have usually 5 or less. Here is great website page that explains prolegs  and their differences.

Here's the Rose Plume Moth Caterpillar to show you a comparison:

Rose Plume Moth Larvae (Caterpillar)

Rose-slug Sawfly Larvae

Sawflies tend to have rounded heads, with visible eyes.

Knowing the difference helps to ascertain that BTK  as a pest control, will be ineffective against the sawfly larvae.

Hand removal has done the trick in this instance, but I would use neem oil and or oil based pest spray control in early June as a preventative. It coats larvae and any eggs that hatch on the underside of the leaves, where the adults have strategically placed them. One to two applications would do the trick. Thankfully, this European introduction, only produces 1 generation per year.

At least the Koi will enjoy a light snack!

Let's see what else our roses will endure this summer.