This way you can effectively combat thrips! –

This way you can effectively combat thrips!

Also called “storm beasts” or “August beasts”, thrips are small (1 to 2 mm) stinging and sucking insects. They are nevertheless recognizable by their long, non-membranous feathered wings. So it is impossible to confuse them with mealybugs or harmful aphids! However, like the latter, thrips are very difficult to remove from plantings once established. It can then cause significant aesthetic damage and weaken your plants. And for good reason: they hide on the undersides of the leaves to feed on their sap. Gardeners must therefore be vigilant and act quickly to stop the spread of this insect and its larvae. Here’s how to achieve biological control of these unwanted pests without chemical-based insecticides.

Who are we dealing with?

Credit: Wikimedia Commons/Daiju Azuma

These insects belong to the Thysanoptera family, which consists of about 3000 species of thrips. However, the berry thrips (Frankliniella occidentalis) are among the best known. Very prolific, this elongated insect is very common in greenhouses, conservatories and houseplants. Nevertheless, it is also found outdoors when the environment is warm and the humidity is low. In general, populations explode with May to September. Difficult to distinguish with the naked eye, you will have to rely on the silver marks they leave on the plants or give you a good magnifying glass to identify them under the leaves of infested plants.

What are the risks for plants from a thrips invasion?

damaged leaf thrips
Credit: iStock

They empty the contents of the cells of the plants after puncturing the tissues of the plants. The sting releases poisonous saliva. This then gives rise to gray spots and ugly discoloration. The leaves begin to wilt and the young shoots undergo deformation which can lead to poor growth, even necrosis. Set the flowers deformation of the petals. Usually the plant does not die. However, she becomes more exposed to diseases cryptogam and viral (tanned tomato, etc.). It can also reduce the yield.

The plants most targeted by these little beasts:

That bugs appreciate greenhouse crops and houseplants. However, some plantations are more sensitive to it!
Garden vegetables: broccoli, cabbage, cucumber, beans, turnips, onions, leeks, radishes, tomatoes and radishes.
– Fruit: strawberries and raspberries
-Plants: azaleas, begonias, chrysanthemums, orchids, roses
– Fruit trees, olive trees and shrubs in the ornamental garden.

Thrips Infestation Prevention

thrips on a leaf
Credit: Flickr/Scot Nelson

– Adopt crop rotation to break the reproductive cycle of this species.
– Limit proliferation by a humid and ventilated atmosphere. Spray the plants with water. If the plant is not too afraid of fungal diseases, then also spray the undersides of the leaves with water. In addition, you can spray these pests with a strong jet of water from a garden hose or in the shower to repel these small phytophagous insects.
-Plant garlic, clover or flax plants at the base of the plants they prefer for a protective repellent effect.

And what treatment once the thrips have been placed?

thrips under a leaf
Credit: Flickr / Maximilian Paradiz

-Venue blue sticky traps, if possible associated with pheromones. Thrips are attracted to this color and with these traps you are less likely to catch beneficial insects in the garden.
– Invite help insects that: their natural enemies : mites (Amblyseius cucumeris), lacewings (Chrysopa carnea), nematodes, insects, etc.
-Use a garlic decoction by soaking two cloves of garlic in a liter of water for 24 hours. Then add a tablespoon of dishwashing liquid or better black soap and canola oil. Then spray the affected areas. Repeat every 5 days for a month.
-You can also just dilute 4 to 5 tablespoons black soap in a liter of water.
-Sprinkle with diatomaceous earth or dilute sweet orange essential oil to spray on infested plants.
– After the treatment, perform a repot your plants in a clean pot with new, healthy potting soil.