Hello readers,
In this series I'm going to break down the basics of garden pests, what to look for, what climate attracts them and methods of getting rid of them. Today's topic: the sawfly, specifically the rose sawfly. There are six different sawfly varieties, some attacking hibiscus and trees like the pear, ash, oak, pine and dogwood. And the other, the rose sawfly or roseslug attack, well, roses.
Rose Sawfly:
What are they?
They are wasps that don’t sting. Not a slug or a fly, although the adults look like flies and larvae look like caterpiller.
Color = black
Growing stages?
Egg, larva, pupa, and adult
One generation per year.
Larvae feast for 4-6 wks after hatching
They like to feast in groups
Larva look like hairless caterpillars with a dark head
Almost like a mix between a green caterpillar and a grub
They are roughly 1/2-2” long
Pupae will overwinter in the soil in cocoons
When do they emerge?
From late May to early June
When temps are over 50 degrees
They eventually crawl to the ground and spin cocoons to await the next year
How to ID damage?
Skeletalized and/or holey leaves, everything eaten but the veins
Clusters of brown and dried, skeletonized leaves
How to prevent?
Regular monitoring
Keep plants healthy with fertilizing and watering routines
Strong plants won’t be as affected by these pests
How to control the issue?
Horticultural oil
Insecticidal soap
Remove larvae by hand and drop in soapy buckets
Knock them off with water
Introduce parasitic wasps or beetles