How to get rid of thrips in your garden.
Thrips are small microscopic insects that range from 0.5mm to 14mm in size. There are about 6000 types of thrips and most of them feed on plants. These insects feed on plants by puncturing the outer layer and sucking out the cell contents. This leads to silvering, and discolouration of the leaf’s surface which eventually kills the plants. They also leave excrement on the plant’s leaves and this can be seen as black varnish-like flecks. Plants affected by these insects should be isolated as they can be blown to healthy plants through winds.
The life cycle of thrips
The life cycle of thrips comprises six stages. They are the egg, two larvae stages, two pupa stages and the adult stage. Thrips can lay up to 100 eggs within 2 days. The female makes an opening in the plant tissue and deposits an egg. The larvae feed on the plant material. The pupa stage is the resting period. The wings start to develop in the pupa stage and are fully formed in the adult stage. The life cycle of thrips is between 2 to 6 weeks.
Plants most affected by thrips
Most susceptible plants include houseplants, flowers and vegetable plants.
Damage caused by thrips
Symptoms include stunted growth, damaged leaves, tiny pale spots on leaves, silvering and discolouration of leaves.
How to control thrips in your garden
Neem Oil
Neem oil contains a compound called azadirachtin that can kill thrips and other insects. Mix 3 teaspoons of neem oil and 1 teaspoon of dishwashing liquid with a gallon of water. Spray this liquid on the plant’s foliage.
Diatomaceous earth
Diatomaceous earth contains 80 per cent silica and kills thrips by dehydrating them. Sprinkling a thin layer of DE on the soil and the base of the plant. This can kill the pupae that live in the soil.
Insecticidal soap
Insecticidal soap kills soft-bodied insects like thrips, mites, aphids and mealy bugs. Take one gallon of water and mix 2 and a half tablespoons of liquid soap before spraying on your plants. The best time to spray is during the early morning or evening time.
Reflective mulch
Reflective mulch can be effective for detaining pests when your plants are small. If your plant has grown big and formed a canopy it might not be much useful. The bright light from the foil disrupts these insects and confuses them. Placing an aluminium foil in the plant’s base is an effective way to deter these insects. You can also cut them into strips and mix them with the mulch.
Sticky traps
Using blue and yellow sticky traps can help to trap these insects. You can buy them from the store or make your sticky traps.
Beneficial insects
Beneficial insects such as green lacewings, pirate bugs and parasitic wasps can help to control the population of thrips. Growing different types of plants can help to attract these beneficial insects. Here are a few plants that you can grow to attract beneficial insects to your garden.
Companion Planting
Thrips hate certain plants such as garlic, basil, catnip, mint etc. Growing them near your vegetable and flower plants can help to repel these insects. Here is an article about companion planting.