Wisteria is a vigorously growing vine that doesn’t require much care beyond regular pruning. As a result, it isn’t too susceptible to many pests, but that doesn’t mean that you’ll never discover something is eating your Wisteria. Finding that something is munching on your plants can be very distressing, so you’ll want to figure out what it is as quickly as possible.
If something is eating your Wisteria, it is most likely an insect of some kind. Because of Wisteria’s toxicity, most animals will not eat it. However, aphids, borers, scale insects, and caterpillars are the most common pests that can affect your Wisteria. Birds and large bees may also cause damage.
This article will discuss the different animals and insects that may eat your Wisteria. You’ll also learn how to tell if something is eating your Wisteria’s flowers and leaves and what you can do about it.
Is Something Eating Your Wisteria?
Problems with plants can sometimes be challenging to diagnose. For example, discoloration, leaf loss, or wilting can often be signs of watering issues, disease, or pest activity, making it hard to figure out what exactly is causing your plant’s distress.
However, there are some signs and symptoms that strongly suggest pest activity. The mere presence of pests doesn’t mean that they’re having your Wisteria for lunch, so how do you know if something is eating your Wisteria?
Holes in leaves and jagged leaf edges are indications that something may be eating your plant. Missing leaves that aren’t visible on the ground below are evidence that something consumed part of your Wisteria. If you find that large sections of the vine are missing, it could be the work of a hungry critter.
Less apparent indications could be lines in the leaf or flesh that look like tunneling under the surface. Small spots are sometimes the result of insect larvae hatching and feeding on leaves.
Which Animals Eat Wisteria?
Wisteria is a mildly toxic plant, so it’s not especially appealing to nibbling animals like many of the other ornamentals you may have in your garden. If you have a problem with deer and rabbits eating the plants in your garden, Wisteria is a good option for a plant that’s a little more resistant to nibblers passing through.
Some people have reported birds (especially pigeons) eating their Wisteria’s buds or flowers. This is certainly a possibility in some instances. However, it’s much more likely that birds attempt to eat the small insects that may be in or on the Wisteria’s buds and blooms, causing them to become damaged or fall off in the process.
As a general rule, animals don’t eat Wisteria because of its toxicity. However, insects are a different story.
Which Insects Eat Wisteria?
Insects are typically the culprits when it comes to a pest nibbling and causing damage to your plants. Though Wisteria isn’t especially susceptible to pest damage, it’s not entirely immune. There are several insects that can cause damage by eating parts of your Wisteria. If you’re wondering what’s eating your Wisteria’s leaves, it’s probably an insect of some sort.
Aphids
These tiny insects pose problems for many plants. An aphid pierces tender parts of the plant (like the underside of the leaf) and sucks out fluids. A few aphids here and there are harmless, but large populations or infestations may cause more significant problems.
Aphids can cause your Wisteria leaves to turn yellow, curl on the edges, or become discolored. They also leave behind sticky secretions that can promote mold or fungal growth.
Ladybugs, lacewings, and the syrphid fly are all-natural predators of the aphid, so a healthy population of these insects can help control them in your garden. However, if your Wisteria is overrun with aphids, you may need to prune away heavily damaged leaves. A strong stream of water can knock unwanted pests off your plant, but if they keep coming back, you may need to use insecticidal soap or horticultural oil (neem oil) to control the population.
A more natural solution is burying banana or orange peels in the soil around the plants, which is said to repel aphids from the area.
Wisteria Borers
Several varieties of borer beetles can impact Wisteria plants. These pests are usually large with long antennae. They can be brightly colored or dark brown or black.
These borers create holes in the plant’s stems, which can invite disease or wood rot or provide an opening for other pests to take hold. In addition, when the borers eat through vital interior stem tissue, they can disrupt the plant’s ability to transport water and nutrients to all its parts. This is especially harmful to young plants.
Longheaded borers (also sometimes called round-headed borers) are typically brightly colored. However, their larvae are yellowish-white in color with brown heads. They look like grub worms, and they can cause far more damage to your Wisteria than the full-grown beetle. The larvae feed on the wood and tunnel through it, sometimes causing severe damage to the plant.
The best way to prevent borers is to keep your Wisteria healthy. When the plant is healthy and has enough water and nutrients, it can survive even with borer damage. However, if an infestation occurs, you should remove the impacted stems and foliage.
If you use insecticides, they’re most effective when applied before the adult beetles lay eggs. That way, when the larvae hatch, they will consume the chemicals and die off. Spinosad or Bacillus thuringiensis is the most effective for young borers and larvae.
Wisteria Scale
Many types of scale insects can affect all kinds of plants. These sap-sucking pests start out as soft-bodied insects that develop a hard exterior when they mature. They’re circular and have a dark gray coloration, although some types are dark brown or black, depending on your location.
Scale insects use piercing parts of their mouth to feed on the plant, which causes leaf discoloration, dieback, and leaf yellowing. Sometimes scale, particularly armored scale, is difficult to detect because it doesn’t look like an insect at all.
These pests clump together and may look like an abnormality on the plant. However, a closer look will reveal secretions of a white, sticky substance called honeydew.
To prevent scale infestations, the best defense is a good offense. Healthy Wisterias can withstand small populations of scale insects without causing damage. Natural predators include parasitic wasps and some birds.
For a more extensive infestation, you should treat the area with a dormant rate application of horticultural oil. Follow the label instructions for spraying. You may want to gently brush the scale with a stiff-bristled (but not metal) brush before applying the oil to help it soak through the scale and reach the insects underneath.
Mealy Flats
These insects are of the sucking variety, and they include the large lanternflies. These pests lay their eggs in the stems of plants. When they hatch, the larvae may eat the foliage. The good news is that these insects don’t typically require formal pest control efforts, but if you do need to treat the plant, insecticidal soap is usually effective.
Potato Leafhopper
These insects feed on your Wisteria’s new growth. They can cause significant damage to your plant as they suck sap from the underside of leaves. New growth is susceptible to leaf curling and may become discolored.
If the infestation continues, the leaves may turn yellow or brown, a condition called “hopperburn.” Insecticidal soap is also a good option for controlling this pest.
Caterpillars
Caterpillars are known for their leaf-eating behaviors. Larvae munch on the leaves of all different kinds of plants, including Wisterias. Then, it will often make a shelter using the leaves on the plant. The caterpillar of the skipper butterfly is an example of a large caterpillar that typically eats Wisteria leaves. This insect is green with a brown head.
What’s Eating My Wisteria Buds and Flowers?
Not many animals eat Wisteria blooms because of the plant’s toxicity. However, one potential problem is with pigeons and other smaller birds pecking at the blooms to get at the aphids and other small insects inside. Similarly, large carpenter bees may try to get at the nectar or water droplets inside the tiny blooms, but their large bodies cause damage instead.
Some owners have reported sparrows pecking at their Wisteria buds and blooms, but it’s not really confirmed whether or not they eat them. Either way, they can cause damage when they knock the buds and flowers off the vine.
Protecting Wisteria from Pests
One of the best ways to protect your Wisteria from becoming lunch for a pest is to keep it healthy. Happy, healthy, and well-tended Wisterias can typically handle small infestations on their own. However, if the plant is already stressed, a pesky insect can cause much more damage. The same is true for a young Wisteria.
Some of the biggest problems that Wisteria plants face are the simplest to resolve. The right amount of water and sunshine will keep these vines growing happily for decades. Avoid the temptation to fertilize your Wisteria unless you’ve confirmed the need with a soil test kit. (Read more about fertilizing Wisteria here.)
I recommend using only organic solutions for pest control, like applying neem oil (which can be fairly effective at controlling scale insects) or using insecticidal soap when you identify the culprits.
Be mindful that not every insect on your Wisteria is a pest. Take, for example, the assassin bug nymph (pictured below on a Wisteria plant). These critters may look alarming if you see them covering your Wisteria leaves, but they’re actually beneficial to your garden. These insects prey on other insects that are pests that could cause damage. So, take care not to exterminate helpful creatures.
Putting it All Together
It’s any gardener’s nightmare to go outside only to discover that something has made a lunch out of one of your plants. Whether you’re finding discarded buds on the ground or chewed up leaves, you’ll definitely want to identify the culprit sooner rather than later.
Sometimes, it may be difficult to identify what’s causing the damage to your plant, especially when it’s not immediately obvious that something has been feeding on it. Insects that suck moisture and nutrients from plants may cause discoloration, leaf curling, and general dieback rather than holes or chewed-up leaf edges.
Most often, it’s an insect causing damage to your plant. Remember that the best defense against pest activity in most cases is to try to keep your plant as healthy as possible. Ensuring that it gets enough water and sunlight is crucial to deter pests and keep the plant from suffering too much damage even if you have pest activity.
If you get an infestation, you may need to apply topical treatments. If you have to go that route, try to use organic pesticides only so that you don’t harm any beneficial insects. Many pests have natural predators that can help control the population, which is the best-case scenario.
In other cases, you may need to do some light or heavy pruning to remove damaged foliage. Certain pests or diseased areas will need to be removed from the rest of the plant to prevent damage from spreading. To read more about how, when, where, and why to prune your Wisteria, check out this article.
If you keep an eye on your Wisteria and take care of it well, you’ll notice pretty quickly when there’s a pest problem. A quick response can help to contain any issues and prevent damage. Remember, though, many plant problems display similar symptoms. So, you may need to do more investigating and use some trial and error to find the root cause of your problem and correct it.