Small tan spiders about 1/8 - 1/4 inch spiders on knock out roses

Asked August 1, 2017, 9:26 AM EDT

Hi, My knock out roses are not blooming well and have some leaf damage. 0ne large cane has died. The roses are about 4-5 years old and generally do ok. I fed them yesterday as directed and watered well. I do see some webs and small tan spiders. Should I spray these spiders or are they beneficial? I dont see any slugs. Also, saw a couple of black spiders about the same size as the tan ones. I have picked some of them off the plants. I couldn't find them in your shrub pest pictures. Thanks,

Queen Anne's County Maryland spiders rose slugs beneficial insect

6 Responses

Can you send us a photo of what you are seeing?
If they are truly spiders, they are tremendously beneficial in our gardens and should be conserved. You should not spray them.
They are active predators of other pest insects in our yard, and then also feed birds etc.

It would be easy to miss seeing rose slug saw fly larvae (not a slug really) on leaves as they blend in so well, but they are out there now. Take a look here:http://extension.umd.edu/hgic/rose-slugs-shrubs

You can prune out the dead cane.
Knock out roses bloom, then take a rest before blooming again. You may be in that in-between period. Keep them watered if we go into a time of drought.

cm


Thank you. I'll post some pics of the tan spider. Don't have pics of the black one.

These looks like baby spiders but we can't tell from the photos what species it is. Spiders are tremendously beneficial in our gardens and should be conserved. You should not spray them. They are active predators of other pest insects.

ckc

Thank you, that's good to know
I'll keep an eye out for the slugs. If I do find them, should I try to get rid of them and if so, what is the best treatment?

Picking/squishing, or knocking them off into a bucket of soapy water works well.
This late in the year most of their damage has already been done. Other insects and birds, especially those feeding fledgling babies, also help to control them.

cm

Thanks!