More Common Insect Problems in Roses

Photo provided by FreeFoto

Photo provided by FreeFoto

Yesterday we began discussing the many different insect problems which are common in roses. We discussed how to diagnose and treat insect problems such as aphids, thrips, leaf rollers and spider mites. Today we are going to address four more insect problems which are common in roses and how to treat those problems.

Symptom: Leaves have been eaten leaving a skeletal structure. Unopened flower buds chewed and opened flower buds damaged.

Cause: Beetles—The most notorious of these is the Japanese beetle. These beetles are a metallic brown color with a green head. The same symptoms can also be caused by caterpillars.

Treatment: An effective and practical approach is to spread plastic or a cloth on the ground and gently shake the plants to remove the beetles. If you place them away from your roses, then traps are also effective. You will want to spray your roses with an insecticide that lists beetles as a target pest. Your roses will need to be sprayed when the problem is first detected, either in the spring or the late summer. If the beetles are in the larvae stage, then Spinosad will work very well on them or on caterpillars. Remember, that Spinosad is an organic chemical that will control most of the insect problems in your roses.

Symptom: Drooping, unopened buds, accompanied by a small discolored stem slightly below the bud.

Cause: Rose Midge—this is a small fly that pupates in the ground below the rose bush. Midges fly up and lay their eggs in the soft upper stem of the rose plant. The hatched larvae then eat the stems and cause breakage.

Treatment: Spread a systemic insecticide granule on the ground to control the pests. Sprays are of a very limited value with the rose midge because of their development below the ground. Spinosad may work to kill the active insects on the plant, and I would be willing to try it.

Symptom: Holes in pruned cane ends. Circular pieces cut from leaf margins.

Cause: Leaf cutter bees—these insects use the circular leaf pieces for egg partitions inside of the burrowed rose cane.

Treatment: Control by applying white glue to the cane ends. The leaf cutter bee is a beneficial insect in the garden as it is an effective garden pollinator. I strongly recommend against eradication of this insect. Instead, I recommend using the above preventative measure to lessen any damage to your roses.

Symptom: Wilting and dying foliage at the top of the rose bush. Leaves may turn yellow and drop off the plant.

Cause: Rose cane borer—These pests are the larvae of sawflies, some wasps and bees. The rose cane borer enters the rose from the top of any pruned rose canes. These pests search for freshly pruned stems of the rose plant to lay their eggs on in the late spring or early summer. The eggs then hatch and the larvae bore their way by eating into the center of the rose plant down the length of the rose cane.

Treatment: The most effective method of treatment is to prune the rose bush below any area of damage. You may need to prune the cane a couple of times to find an area that is not damaged. Then you will want to place a little dab of white glue over the pruning cut. This will prevent the insects from successfully laying new eggs on the freshly pruned rose plant. Another idea to aid in prevention is to try some companion planting. These insects do not seem to like Allium, so planting some near your rose bushes may help to repel them.

Now that you know some of the most common insect problems with roses, which ones have you had experience with? Leave me a comment and share.

Identifying and Treating Insect Problems in Roses

Photo provided by Major-Maróthy Szabolcs

Photo provided by Major-Maróthy Szabolcs

When your roses are given the proper attention and a healthy environment, they will stay healthy and will flourish for many years. However, even under the best of conditions, your roses may on occasion suffer some form of disease or be troubled by common pests. Inadequate drainage, poor soil, insufficient water, lack of nutrition or other environmental problems may encourage pests and disease to take hold of your roses.

Roses may be affected by either environmental conditions or living pathogens. If you find that the damage to your roses is uniform, then it is usually an environmental or cultural problem that you are dealing with. However, if there is visible damage that is not uniform, then you are usually dealing with a problem with living pathogens.

Today and tomorrow I will discuss how to identify and treat the most common insect problems in your roses. Next week I will discuss how to identify and treat the most common diseases which may affect your roses.

Symptoms: Masses of small insects on the buds and leaves.

Cause: Aphids—these are green, red or black bugs which are soft and about 1/8” long. They can be found in clusters and will be found mainly on the new growth. These pests appear in the spring and can remain all summer.

Treatment: You will want to begin by simply hosing the insects off of the rose plant with water. Should you need to treat the problem further, then most of the commercial insecticidal sprays are effective. You can also use a solution of household dish soap and water. This is done by using just a few drops of dish soap in a quart spray bottle and filling it up with water. Then just spray it on your roses. There are also many aerosol insecticides labeled for plant pests that will also work. Just be sure to read the label on the product to verify which insects the product will control. Spray the product upwind and ensure that you apply a coverage that is thorough. Or if you want to just make life easy on yourself, go to your local garden center and purchase a product called Spinosad. This is an organic chemical that will control most insect problems in your roses.

Symptom: Buds are distorted and bloom tips appear discolored.

Cause: Thrips—these are light brown insects which are very slender and are about 1/8” long. These insects can appear inside petals and they move very quickly. They are spread by the wind.

Treatment: You will want to apply a systemic insecticide that lists thrips as a target. You will want to apply this when new growth of 1” or more emerges in the spring. Contact treatments can be used on a rotational basis when the rose buds are pea-sized. Or, just make life easy on your self and go and get some Spinosad from your local garden center.

Symptom: Leaves stuck together, unopened buds with holes.

Cause: Omnivorous leaf roller—this is a moth larvae that makes a cocoon type of structure with leaves.

Treatment: Remove all of the cocoon structures from your rose plant. If you need to treat your rose plant further, then apply a systemic insecticide that targets leaf rollers when new growth of 1” or more emerges in the spring. Contact treatments can also be used on a rotational basis when the buds of the roses are pea-sized. Personally, I just use the Spinosad as it is easier.

Symptom: Leaves appear fuzzy and yellow on surface; underside has small red specks, webbing or spider-like insects may be seen.

Cause: Spider mite (red spider or 2-spotted mite)—these insects are microscopic in size, but are visible to the naked eye. Spider mites thrive in hot weather.

Treatment: Apply an insecticidal soap, horticultural oils, miticides, or high pressure hose water, or my favorite product, Spinosad. All of the treatments must be applied to the underside of the leaves of the rose plant, in order to come into contact with the spider mites. Keep the roses well watered during hot weather and avoid dust on the leaves of your plants.

Tomorrow I will discuss Beetles, Rose Midge, Leaf Cutter Bees and Rose Cane Borer. Which of the above treatments do you favor for the treatment of your roses? Leave me a comment and share.

Beneficial Insects in Your Garden

When you think of insects and your garden, you are more than likely thinking about how to get rid of them. But there are actually some insects that are beneficial to have in your garden. These little soldiers can do a lot of good and you will be glad that you took the time to invite them to build a home in your garden. Some of these beneficial insects are the ladybug, praying mantis, beneficial nematode and the green lacewing.

In order to get the most from these beneficial insects, you will need to closely monitor your garden area. Be sure to check your plants regularly so that you will know when there are pests present. When you identify a pest problem, you will want to determine which type of beneficial insects will be the best solution. You will also want to be sure to release the beneficial insects when the pest population is low to medium. You must have a fast response to the problem in order to get the best results.

Here is a little information about each of the beneficial insects that you will want to purchase and introduce to your garden:

Ladybugs
Ladybugs are more than just pretty or a fun moment and a childhood rhyme. They like to eat aphids, thrips, spider mites, whitefly and whitefly larvae. They also love to feast on other plant pests which are considered to be sap sucking. Watching these insects in action will have you singing a new tune and requesting that they stay in your garden.

Praying Mantis
This bug is just plain cool. They are fun to watch and they are a huge benefit to your garden. They attack many of the flying and crawling pests that will eat your plants and flowers. Here is a short video that shows one of these cool bugs feasting on a potato bug:

Beneficial Nematodes
These are impossible to actually see with the naked eye, but the work they do is visible. These bugs prey on several of the soil born pests that can bring devastation to your yard and garden. They are considered to be especially effective on the crane fly larvae.

Green Lacewings
These insects make a great addition to your garden and you will find them to be especially beneficial. They feed on aphids, whitefly, thrips, leaf-hoppers, spider mites, scale crawlers and many more pests.

Introducing these friendly and beneficial insects into your garden can be a fun project. Most are fun to watch and it is a safe and organic solution to the pests that may plague your gardening efforts. What are some other non-traditional pest control methods that you can think of for your garden?