What is eating the stems of my plants? If you’ve asked yourself this question at least once, chances are you have a garden full of plants with damaged or half-eaten stems, and no one wishes to suddenly see and discovery that they have some half-dead plants and fruits as a result of damaged stems.
Your first suspects might be rodents, but insects are most likely culprits of damaged stems. To help you reach to the bottom of this mystery, here are six possible insects that might be responsible for eating the stems of your plants.
Contents
Types of Pests That Attack Plants’ Stems
1. Spider Mites
Spider mites are not considered true insects, but arachnids and are relatives of spiders, scorpions, and ticks. Like spiders, they have four pairs of legs and can produce white silk-like webs. Their tiny bodies are oval-shaped with no antennae, and they only grow up to less than half an inch as adults.
– Characteristics
Depending on the species, spider mites often look reddish-brown or greenish in appearance, but some might have spots or stripes and can only be seen under a microscope. Spider mites enjoy feasting and laying eggs on plants such as potatoes, strawberries, beans, chickpeas, tomatoes, clovers, apples, peppers, etc.
With over one thousand species, including the red spider mite, spruce spider mite, hemp russet mite, etc., these eight-legged creatures can cause much damage to their favorite plant hosts.
They are frequently found on the underside of leaves and mostly live in colonies because they multiply fast. This allows them to wreak havoc on the stems of plants within a short time while going unnoticed.
– Damage Symptoms
Spider mites are sucking insects with mouthparts that allow them to pierce and suck on plants to extract fluids and chlorophyll from their tissues. As a result, you will first notice some tiny white or yellow dots on the underside of your leaves, and they will be showing in an obvious way.
Once they start reproducing, you would even have some significant infestation that can destroy your stems and cause your foliage to change to bronze or yellow, with their edges curling and eventually falling off.
Not only that but they would also do their best to protect their eggs by hiding them under a coat of fine silk webbing, which can prevent light and water from reaching all parts of the stems, thereby killing the plant. It will also start gathering dust and dirt, making your garden look aesthetically unappealing.
– Control Tips
There are many ways to control and eliminate spider mites from your plants. Firstly, you can spray neem oil all over infected plants, but you must make sure that you keep such plants away from children and pets.
You can also use their natural predators, such as ladybugs, big-eyed bugs, lace wigs, etc., can eat them off your plants.
On the other hand, soft pesticides, or miticides are very good for killing off these pests from plants. Plants that have been wholly infested should be cut-off and thrown in the compost pile. Since spider mites enjoy dry, dusty conditions, ensure your plants are properly and regularly watered.
2. Flea Beetles
Flea beetles are jumping insects with shiny bodies with enlarged hind legs that allow them to jump quickly when disturbed.
There are over five thousand species of this insect, including the potato flea beetle, crucifer flea beetle, striped flea beetle, etc., and they all have varying appearances. Some are tan, black, or brown, with yellow or blueish-green metallic stripes on their outer wings called elytra.
– Characteristics
These leaf beetles are small and can only grow less than 0.15 inches when mature, but they are strong fliers, making it difficult to control them. Flea beetles are notorious for feeding on the stems and leaves of plants such as broccoli, tomatoes, eggplants, peppers, cabbage, collards, etc.
On the other hand, in spring, female flea beetles lay eggs in the soil beneath or the undersides of the leaves on these plants. When these eggs hatch, they start feeding on the roots of the plants, then move to feed on the stems when they are adults.
– Damage Symptoms
Although some species of the flea beetle are regarded as beneficial insects due to the fact that they act as agents of weed control, others cause severe destruction to the stems of plants.
They damage stems by creating small, irregular holes known as “shot holes” in the foliage. On plants with thicker foliage, flea beetle damage appears as pits, making them look like sieves. These damages can kill new seedlings and cause stunted growth or death in mature ones.
– Control Tips
Flea beetles are attracted to the tallest crop available, so you can plant a trap crop like Chinese southern giant mustard or radish before your main crops and spray them with a chemical pesticide.
In addition to this, you can also spray neem oil on your plants to kill the beetles or introduce natural enemies like the big-eyed bug or lace wig larvae to eat them up. Furthermore, using row covers is an excellent way to keep beetles out of your plants but ensure you remove them before the flowers bloom to allow pollination.
3. Aphids
Aphids, also called plant lice or greenflies, are small, soft-bodied insects that always seem to find a way into every garden. They are often green in color, hence the name greenfly, but some can come in black, pink, brown, white, gray, yellow, or red.
There are about 4000 species of aphids with sizes ranging from one to 0.4 inch, making them barely visible to the naked eye.
– Characteristics
Aphids feed in colonies and are wingless as adults. However, they can develop wings when the population becomes too large, and they must fly to look for other food sources.
They feed mainly on the soft stems and leaves of peppers, tomatoes, roses, spinach, potatoes, dahlias, cabbages, etc. They pierce and suck on the sap on the undersides of these leaves or stems using their piercing mouth parts, mostly they would feed on these vegetables.
– Damage Symptoms
After sucking the nutrients from stems and leaves, aphids produce a sweet, sticky substance called honeydew as their waste product. This honeydew can attract ants or cause sooty mold, which leaves the leaves and stem black. The leaves can also become yellow and curled or stunted with galls on them.
– Control Tips
One of the best ways to get rid of aphids is to spray the plants they have infested with a soap and water mix. You can also mix oils such as neem, rosemary, thyme, or peppermint in water and spray on the leaves. As these are repellents through the aroma they release.
Natural predators, such as chickadees, ladybugs, or green lacewings, can be introduced to prey on aphids. You can also grow aphid-repellent plants like onions, catnip, and garlic to deter them from your garden.
4. Japanese Beetles
A Japanese beetle infestation in your garden can pose severe problems for your plants. This is because these beetles feed on a wide variety of plants, up to 300 species, and feed in large groups, using pheromones to attract other beetles, thereby causing widespread destruction.
They not only feed on the stems of these plants but also feed on the fruits, flowers, and roots. Their favorite plants include elm, pawpaw, marigold, carrot, roses, birch, spinach, mint, soybean, apple, etc.
– Characteristics
Japanese beetles can grow up to half an inch as adults with a metallic green thorax and head, as well as copper-brown elytra that don’t fully cover the abdomen. You would first notice the way they have brown-colored heads with long brown hairs scattered all over their bodies.
They also have five patches of white hair on either side of their abdomen and two patches of white hair on the bottom abdominal segment. Their grubs are white or cream-colored larvae that are C-shaped when at rest. These grubs feed on and complete their life cycles in the roots of plants.
– Damage Symptoms
Japanese beetles feed on the upper surface of leaves and the mesophyll but leave the underside undamaged. They also create holes in the leaves and feed on tissue between veins.
This causes the leaves to be skeletonized and initially have a whitish or lacy look before they turn brown and begin falling off. The grubs feed on the roots of lawn grasses which will cause the patches of grass to die or turn brown.
– Control Tips
One of the ways to eliminate these pests is to hand-pick them off your plants. Although this might be stressful and time-consuming, Japanese beetles are easy to identify and shake off, so drop them in a bucket of soapy water for them to die.
Geraniums cause Japanese beetles to get dizzy from the natural chemicals in them. Therefore, you can plant geraniums as a trap crop, causing the beetles to die after feeding on their blossoms and fall off, then pack and dispose of them. In addition, you can also use row covers, but remove them when your plants are ready to bloom or be pollinated.
5. Tarnished Plant Bug
The tarnished plant bug is a tiny flattened insect that grows to about a quarter of an inch long and has been recorded to attack over 350 plant species. The tarnished plant bug is an oval-shaped, bronze, reddish-brown, or dark-brown, a quarter-of-an-inch insect with a diamond shape on its back resulting from overlapping wings.
– Characteristics
Their newly hatched nymphs are yellowish-green and wingless, but more mature nymphs are green or greenish-brown in color with black spots on their thorax and abdomen and wing pads. It has long antennae and wings, which is what makes them quick.
The tarnished plant bug has a needle-like piercing-sucking mouth part that allows it to pierce plants and suck out sap and other nutrients but also inject a toxic digestive enzyme into the plant to help break down its tissues. This pest is common to fruits like peaches, strawberries, grapes, cabbages, cucumbers, turnips, raspberries, etc.
– Damage Symptoms
Damage caused by tarnished plant bugs includes discolored stems, deformed leaves, abortion of young buds, and deformed fruits. The toxic enzymes introduce into the leaves when the insect is feeding causes the areas around their feeding site to have yellow or brown marks or wilt. The flowers of plants may also begin to turn brown and drop.
– Control Tips
Tarnished plant bugs are mobile insects, which might make them difficult to get rid of. Introducing parasitic wasps, big-eyed bugs, spiders, etc., into your plants will help eat up the eggs and nymphs of these bugs.
But you can use garlic spray on your plants to prevent them from laying eggs. You can also use floating row covers to protect your plants from these bugs’ attacks.
On the other hand, one of the most effective ways to get rid of these bugs is to control weeds and remove debris effectively. This means mowing weeds to prevent them from forming young buds. You should also cut the grass around your garden to reduce their breeding sites.
6. Tomato Hornworm
Tomato hornworms are the larvae of the five-spotted hawk moth and are one of the garden pests mostly feared by gardeners because they can cause much destruction to plants, as the name implies.
Note that this worm uses mainly tomato plants as its hosts, as well as eggplants, potatoes, and peppers. The tomato hornworm is most active at night and feeds on its host plants’ leaves, flowers, and stems.
– Characteristics
The tomato hornworm is a large, robust, green larva that grows up to five inches long with white and black spots and V-shaped stripes on each side of its body. It also has a small black horn-like projection on the rear end of its abdominal segment, hence its name.
Despite its large size, the green color of this worm allows it to blend easily among leaves without being spotted, these are the key features that makes them distinguished.
– Damage Symptoms
Tomato hornworms start feeding from the upper part of plants, so look for stems with missing leaves or ones with wilted leaves. You would also notice large holes on the leaves or leaves that have been chewed or gone missing.
They also leave visibly black or dark green droppings on top of the leaves as they feed, so if you look at the bottom of the leaves, you will most likely find one of these worms.
– Control Tips
Since tomato hornworms blend easily into plants, you can use a UV light to search your plants for them at night. They will start to glow under the light, so you can pick them up and drop them in a bowl of soapy water to die.
You can also introduce some of their natural predators, such as lacewings, ladybugs, and wasps. Diatomaceous earth, made of fossils of tiny aquatic animals, is also perfect for killing these pests when sprinkled on them.
You can also use an organic pesticide called Bacillus thuringiensis that poisons the worms when ingested.
Conclusion
Having insects feed on the stems of your perfectly growing plants can be nerve-racking, but knowing what exactly is causing the damage and how to look out for them is the first step in getting rid of them. And that is what we have provided in this article. Here are a few things to note:
- Other insects that could be eating your pants’ stems are cutworms, whiteflies, squash bugs, stem borers, and earwigs.
- You can grow indoor plants to reduce the risk of their stems being eaten by pests.
- You should always ensure your garden is clean and weed-free to prevent attacks on your plants.
Not only that, but you now know everything that should help you identify and get rid of whatever is eating your stems, so take the proper steps to protect your plants and allow them to grow healthy.
References
- https://extension.umn.edu/yard-and-garden-insects/flea-beetles#:~:text=Adult%20flea%20beetles%20cause%20the,is%20unique%20to%20flea%20beetles
- https://www.rhs.org.uk/biodiversity/aphids
- https://en.wikipedia.org/wiki/Japanese_beetle
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