If your plants are diseased and growing unhealthily, they could be infested with thrips. Thrips are one of the many common pests found in outdoor and indoor plants. These insects suck on the juices and saps of plants with their chewing mouthparts.
Their sucking can destroy plant tissues resulting in stunted plant growth, distorted and ugly leaves, branches, and blooms, and transmit viruses or bacterial diseases to plants. It's essential to get rid of them on time, so here are the tips:
What Are Thrips
Thrips, also known as, Thysanoptera or thunderflies, are minute, slender insects about the size of a sewing needle. They are translucent and vary in color from yellow to brown or black, with soft bodies and asymmetrical mouthparts.
They have narrow fringed wings that do little to help these insects to fly. There are more than 6,000 species of thrips, all of which go through a complete metamorphosis. They have four distinct life stages, including egg, larva, pupa, and adult.
Most of them are beneficial bugs, except for a few hundred that are harmful to plants. These harmful bugs are named according to the plants they like to feed on, like onion thrips, pea thrips, gladiolus thrips, or rose thrips.
Unfortunately, thrips are difficult to identify because they are tiny, like 1/20 inch long. The only way to notice them is the damaged plants. Affected plants are twisted, discolored, and scarred with pale, splotchy, and silvery leaves. The plants may be dead as well.
You can confirm whether your plants are infested with thrips with sticky traps. You lay out these pest control tools covered in non-toxic glue and wait for the insects to land on them. You can lay out these traps near your plants. The number of insects trapped may indicate where they are coming from and how severe an infestation is.
Thrips Damage
Identifying Thrips Damage
The only way to identify thrips is by the damage they cause to plants. So what do their damages look like? Here are a few signs you should pay attention to.
Plants Thrips Prefer
Thrips feed on various plants, but some are especially attractive to them. These insects love peppers, onions, tomatoes, beans, carrots, and other garden vegetables. They also feed on light-colored flowers like dahlias, impatiens, gladioli, and roses.
If you have all of these plants and crops in your garden, it is like a buffet for the thrips, and there is a high possibility your plants might be infested.
Signs of Thrips Damage
Silvery or discolored leaves
Brown or yellow flecks on the leaf surface
Curled, twisted, or stunted leaves
Black sticky spots (insect excrement)
Damage to Flowers and Fruits
Malformed flower buds with brown streaky or spotty petals
Premature flower drop
Scars and blemishes on the surface of fruits, reducing overall harvest
Once you are sure thrips are damaging your plants, you need to know how to get rid of them. Here are some thrips treatments.
Pruning
The best thrips treatment is to remove infested branches, leaves, blooms, and stems. This means removing parts that have silvery patches, stippling, or curled foliage. Plants with irreparable damage might have to be thrown away, no matter how attached you are. This prevents the thrips from spreading to other plants.
Pruning helps eliminate insects and their eggs, thereby reducing the overall population. A smaller insect population means less damage to the healthy parts of the plant. Furthermore, removing damaged foliage allows the plant to direct its energy towards recovery and produce healthy new growth, increasing its resilience against thrips. Pruning also opens up the plant canopy, making it easier to apply insecticidal sprays or other control methods to all parts of the plant.
Spray With Water
If you want a quick and easy solution, spray your plants with water from a garden hose. The force from the water will physically knock thrips off the plant. Focus on the undersides of leaves where they like to hide. This blast of water can also dislodge their eggs and affect their reproduction cycle.
For indoor plants, you can use soap water solution. Mix two teaspoons of dish soap with a gallon of water and fill it in a spray bottle. Spray the solution on all parts of the infested plant. This helps prevent the thrips from damaging the plants but not from attacking the plants. The insects will return after the danger has passed.
Use Castile Soap Solution
You can also use a solution made of castile soap, a cleaning product made entirely from vegetable oils and free of synthetic ingredients found in conventional soaps and detergents. This natural soap is ideal for those who prefer eco-friendly ways to remove the thrips.
This soap solution contains fatty acids that break down their outer coating, which helps retain moisture and protect them from dehydration. Lack of oxygen and water will eventually kill these insects.
Note that the insects have to come in contact with the solution to be effective. So remember to spray thoroughly, including the undersides of leaves, and repeat every few days according to the product label.
Diatomaceous Earth
Diatomaceous Earth (DE) is a powder made from the fossilized remains of microscopic aquatic organisms.
DE might seem like finely milled powder, but it has microscopic sharp edges that puncture the thrips when they crawl across DE. Their bodies d then dry out, and they die. Like castile soap solution, DE is an eco-friendly way of getting rid of thrips.
Apply DE to areas where thrips are present. You lightly dust the soil of your plants and the undersides of leaves. Avoid over-applying, as it can harm beneficial insects as well. You might have to apply DE after rainfall and watering, as it loses effectiveness once it comes in contact with water.
Also, remember to put on gloves and a mask, as DE can irritate the skin and lungs if inhaled.
Introduce Natural Predators
Releasing natural predators is an effective long-term thrip management. Some common options include pirate bugs, lacewings, thripsum wasps, ladybugs, predatory mites, and nematodes. You can purchase predator kits designed for thrips control from insect suppliers.
Adult ladybugs and larvae feed on thrips nymphs and adults, while the minute pirate bugs feed on all four stages of thrips. The larvae of lacewings are fierce predators that eat everything except the thrip eggs.
The tiny thripsum wasps parasitize thrips pupae by laying their eggs inside them. When the wasp larvae hatch, they feed on the developing thrips, effectively eradicating them.
Light Reflecting Films
Thrips are tiny insects that navigate around plants using light cues. By reflecting light around infested plants, you can disrupt their navigation system, making it difficult for the insects to find food and breeding sites.
You can place a thin layer of aluminum foil on the base of your plants, but avoid this on a hot day. The aluminum foil heats the plant and dries it out. Additionally, they are only effective on smaller plants.
Although reflecting light helps, it is not the best solution. This is effective only on young thrips, as adult thrips can adapt to altered light conditions over time. Using such material may also ruin the aesthetics of your garden. It is best to use this method in conjunction with others.
Neem oil is a natural pesticide derived from the neem tree. Every professional gardener owns it because, unlike synthetic pesticides, it eliminates harmful insects like thrips without affecting beneficial ones like bees and other pollinators.
Neem oil disrupts the hormones of insects, preventing them from eating and mating. It does not kill thrips on contact, so you will not see the immediate demise of the pests that damage your plant.
Instead, neem oil offers systemic pest control. When absorbed by the plant, the ingredients of the oil remain in the plant's tissue. They are toxic to the insects and prevent them from feeding on the plants.
To use neem oil, wash off the thrips off your plant. Then, mix four teaspoons of neem oil and two teaspoons of dishwashing soap into one gallon of water. Spray the solution on the infested parts of the plant.
Pytherin Spray
Pyrethrin sprays are a type of pesticide derived from chrysanthemums. They are effective against thrips because it is fast-acting. Opt for pure pyrethrin pesticides and not pyrethroid pesticides for something eco-friendly.
The latter contains more synthetic chemicals to make them extra lethal to insects. To use it, spray infested plants twice every four days or follow the product label instructions. Unfortunately, these sprays alone are ineffective.
They only kill adult thrips and not the eggs, so you might have to use these sprays with other methods. Additionally, you might have to reapply often. They break down quickly in sunlight and lose effectiveness within a few hours of application.
These sprays might also kill beneficial insects like ladybugs, so use them carefully.
How To Keep Thrips Away
Getting rid of thrips is a solution to an infestation. It is better to avoid an infestation in the first place. Therefore, you should also know how to keep thrips away.
A dirty and messy garden can attract thrips, so it is vital to keep it clean. Thrips hide in weeds, ground debris, fallen leaves, dead branches, deadheaded flowers, and pruned stems.
These insects feed on the weeds, which gives them energy to reproduce and increase their population. They will then move on to your valuable plants.
Therefore, you need to throw away pruned and dead plants in the compost pile and keep your yard weeded so that thrips do not have a suitable place to lay eggs, overwinter, and raise their babies.
Keep Plants Healthy
Having healthy plants in the garden can also ward off thrips. Thrips cannot pierce the plant tissues of healthy plants as they have a robust cell structure and thicker cell walls.
This prevents them from feeding on the plants and damaging them. Additionally, healthy plants produce natural compounds that repel these pesky insects.
Instead, thrips are attracted to weak and unhealthy plants because they emit volatile organic compounds. This signals to the thrips that they are an easy target. Therefore, it is important to keep your plants healthy.
You can do this by watering your plants according to their needs, providing nutrients with fertilizers, exposing them to adequate sunlight, and addressing pest or disease problems promptly.
Plant Herbs
Planting aromatic herbs alongside your valuable plants can help prevent thrips infestation. Herbs like basil, chives, catnip, and garlic possess strong-smelling essential oils that thrips find unpleasant.
The scent can disrupt thrips’ sense of smell, which they use to communicate and navigate. This disruption makes it difficult for them to locate and feed on your valuable plants.
You can protect your desired plant by interplanting them with rows of aromatic herbs. Do not plant all your favorite plants that attract thrips in clusters. Instead, spread them around the garden with the herbs.
