Spider mites are oval-shaped and can be greenish-yellow or burnt orange. They attack the underside of rose leaves and suck the plant’s inner juices. This will cause a yellowish or white speckling on the top side of the leaves. If a spider mite infestation is large, you may notice fine, silky webbing on the bush. This will cause the rosebush to die if spider mites are not eliminated promptly.
Leaf Tiers
Leaf tiers are small, green caterpillar-like insects that feed much the same as slugs. They spin a web and roll a leaf around their body. The best way to get rid of leaf tiers is to remove infested leaves and burn them. If you live in an area where there is a bylaw against burning, kill the leaf tiers inside the rolled up leaf by removing and crushing it.
Japanese Beetles
Japanese beetles are metallic green insects approximately three-eighths of an inch long with copper wings. They appear on rose blossoms in mid-summer. Use a herbicide or homemade concoction to eradicate them.
Slugs
You will recognize slug larvae by their tapered bodies and yellowish-green color. Slugs will chew leaves down to their skeleton, giving them a lacy effect. Be sure to stay alert for slug larvae. If any appear, spray immediately.
Homemade Remedies for Insect Control on Rosebushes
Aphids
It’s easy to keep aphids away from your rosebushes. Chop one onion and two garlic cloves. Add chopped ingredients to two cups of water. Place in a blender on high for one minute. Strain pulp from the mixture and pour the liquid into a spray bottle. Spray a mist of the mixture on the top and bottom of rose leaves, making sure they are completely covered. Aphids will not feed on leaves that are covered in this mixture.
Another way to keep aphids off your rosebushes is to wrap the base of the bush in aluminum foil. When light hits the foil, it is reflected. This confuses the aphids and sends them on their way.