Caterpillars on Roses: Identification and Control
Roses are one of the most popular flowers grown in home gardens. Their beautiful blooms and sweet fragrance make them a joy to have around. However, roses are also prone to pest problems, including caterpillars that can quickly defoliate the plants. Knowing how to identify and control common rose caterpillars is key to keeping your roses healthy and productive.
In this article, we’ll cover the most common caterpillar pests of roses, how to identify them, the damage they cause, and effective control methods. Whether you’re dealing with a minor infestation or a full-blown caterpillar outbreak, you’ll find the information you need here to protect your roses.
Common Rose Caterpillars
There are several types of caterpillars that feed on roses. Here are some of the most frequently encountered species:
Eastern Tent Caterpillar: These hairy black caterpillars have a white stripe down the back and blue spots along the sides. They build messy silk tents in the branches of roses and other plants, often completely defoliating them.
Rose Sawfly Larvae: Several sawfly species have green larvae that resemble caterpillars. They quickly skeletonize rose leaves, sometimes even eating the petals.
Spicebush Swallowtail Caterpillar: Identifiable by its brown body with large “eyespot” markings, this caterpillar feeds on leaves but doesn’t usually cause severe damage.
Fall Webworm: These fuzzy yellow or black caterpillars with red heads form large webbed nests at the ends of branches, within which they feed on enclosed leaves.
Rose Chafer The larvae of this beetle feed on rose roots, causing poor growth and sometimes plant death. They are C-shaped, whitish grubs.
Leafrollers: Several moth species have green caterpillars that roll or fold leaves to create shelters, damaging buds and leaves.
Identifying Caterpillar Damage
The first sign of caterpillar damage is often chewed or skeletonized leaves. Caterpillars usually feed along the edges of leaves at first, sometimes leaving only the veins behind. As they grow, the damage becomes more extensive, including holes in the middle of leaves and flowers.
Sawfly larvae and other small caterpillars may skeletonize the undersides of leaves while leaving the top surface untouched. Tent caterpillars, fall webworms, and leafrollers enclose areas of the plant in silken webbing as they feed. Frass (caterpillar droppings) may also be visible on leaves or below the plant.
Severe caterpillar damage can lead to complete defoliation of roses. Repeated defoliation weakens the plant, potentially even killing it. Skeletonized flowers or buds that fall off won’t develop properly. Even light feeding damage affects the aesthetic appeal and health of roses.
Controlling Rose Caterpillars
The key to caterpillar control is taking action early, before pests have a chance to multiply. Monitor roses frequently, especially when new growth appears in spring, and be on the lookout for the first signs of damage. Here are some effective control methods:
-
Handpick caterpillars, dropping them into soapy water. Target clusters of young caterpillars and egg masses.
-
Apply Bacillus thuringiensis (Bt), a natural bacteria that kills caterpillars when they ingest it but is safe for people and pets. It’s most effective on small larvae.
-
Use insecticidal soap or neem oil sprays to suffocate and deter caterpillars while minimizing harm to beneficial insects. Spray thoroughly, including undersides of leaves.
-
Encourage natural predators like birds, wasps, and predatory insects that help keep caterpillar populations in check. Avoid broad-spectrum insecticides.
-
Prune out webbed nests or tents and crush any eggs you find to limit reinfestation. Destroy the material so caterpillars don’t migrate back onto the plant.
-
Apply sticky barriers like Tanglefoot around tree trunks to prevent caterpillars from climbing back up after falling or pruning.
-
Protect new growth with floating row covers or apply Bt at the first signs of leaf buds to get ahead of early season damage.
With vigilance and a combination of mechanical, biological, and least-toxic chemical controls, you can keep rose caterpillars at bay. Don’t allow excessive damage to occur before taking action. Avoiding the use of harsh pesticides will help conserve populations of beneficial insects that help keep caterpillar pests under control naturally.
Gardening, Nature & Weather–slightly skewed
First things first: the “little caterpillars” that you see on your rose leaves aren’t really caterpillars. Yes, I know that’s exactly what they look like, but they’re not.
If you recall my “holiday gardening” post about 2 weeks ago, I said that in my climate there were some sawfly larva that showed up between Mother’s Day and Memorial Day in my climate. And here they are.
This is the rose sawfly larva. It showed up the Friday of Memorial Day weekend. You see that on this leaf (and look closely, because it’s a tiny caterpillar the same color as the leaf. It is on the petal nearest to you) the leaf is just beginning to show a bit of damage. More in a moment about that.
Why is it important that these aren’t caterpillars? For organic control purposes. If you want to spray (I generally don’t; I just let the roses get slightly disfigured because there’s only one hatching of these a season in my part of the world)–you can’t us BT which only works for caterpillars.
Also if you do spray, they tend to hide beneath the leaves, so be sure to get the undersides.
Otherwise they will leave your leaves disfigured (with these scrape marks that then often get burned into holes by the sun, making it look like some other disease or insect has been there). Don’t be fooled.
The two sets of leaves in the above photo show early damage and more advanced damage. The top set is the earlier damage, although even there, some of the scrapings and holes have been burned or eaten through the leaf.
As you can see in the bottom photo, the mouth scrapings made by the insect are browned by the sun. It’s not a good look.
What can you spray? Insecticidal soap is a nice remedy for soft bodied insects. Just remember to spray in the evening or first thing in the morning before the heat of the day and before most of your beneficial insects might also be accidentally sprayed.
How to Identify Caterpillars on Rose Bushes
FAQ
Are caterpillars good for rose bushes?
There are many types of caterpillars that feed on roses, though most are considered incidental pests to roses. You won’t think so when you see whole portions of one of your roses seemingly disappear overnight! Although most feed on leaves voraciously, only a few damage or defoliate plants extensively.
How do I get rid of caterpillars eating my leaves?
Use a combination of BT, neem and soap (castile soap). The BT will kill caterpillars that eat the leaves, the neem will ward off the moths from laying more caterpillar eggs and the soap will kill caterpillars and moths on contact (best to spray as close to night as possible to minimize killing beneficial insects too).
What can I spray my roses with?
- 1 Tablespoon white vinegar
- 1 cup water
- 1 1/2 Tablespoons baking soda
- 1 Tablespoon dish soap
- 1 Tablespoon vegetable oil (or any other cooking oil)
Why are there caterpillars on my Roses?
If you see caterpillars on your roses, and some damage to your plants, sawfly species could be the culprits. Read on to learn more about the sawfly larvae you may encounter on roses in the UK, and how to deal with them if you find some in your garden. What Is Sawfly?
Do caterpillars eat Roses?
Caterpillars are among the most common pests on cultivated and wild roses along with aphids, mites, and thrips. Young caterpillars only feed on the soft parts of rose leaves while many mature caterpillar species defoliate roses by eating entire leaves and even the flowers at times.
Can caterpillars damage rose plants?
Caterpillars can cause significant damage to rose plants if left unchecked. However, by implementing a combination of manual removal, biological control, cultural practices, and selective use of insecticides, you can effectively manage caterpillar infestations on your roses.
How to keep caterpillars away from rose plants?
For this method, you can use either diced garlic or cloves. Try sprinkling garlic cloves around your rose plants to prevent caterpillars from coming near. It won’t exactly kill the caterpillars, but it will repel them. Another natural home remedy for keeping caterpillars away from your roses is hot peppers.
Do Roses attract caterpillars?
Some plants have strong scents or produce substances that repel caterpillars. Consider planting marigolds, garlic, onions, or thyme near your rose plants as a natural deterrent. Additionally, interplanting roses with aromatic herbs like lavender, sage, or rosemary can attract beneficial insects that prey on caterpillars.
How to control rose sawfly caterpillars?
You can always start cultural control strategies with early detection. Rose sawfly caterpillars can be managed by controlling them in different ways. Some practical methods are picking them off the rose plant and eliminating them or hitting them powerfully with water spray. Rather than the adults, control methods are directed at the larvae.