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.