How do I control thrips?

How to Effectively Combat Thrips

Thrips are small, thin insects that can cause significant damage to plants both indoors and outdoors. These pesky pests spread quickly and are often difficult to manage. In this blog, you'll learn how to effectively deal with thrips, which types exist, and which methods are best suited for their control.

What Are Thrips?

Thrips are tiny, brown to black insects that grow only 1 to 2 millimeters in length. They have fringed wings and live between 10 and 30 days, depending on the conditions and season. In the Netherlands, there can be up to 7 to 12 generations of thrips per year, and they are active at temperatures between 12 and 30 degrees Celsius. Thrips lay large quantities of eggs on plant material, contributing to their rapid spread.

Thrips Species in the Netherlands

Several types of thrips are found in the Netherlands:

1. California Thrips: This is the most common and also the most damaging species. They are found on various plant types and crops.
2. Tobacco Thrips: These are less problematic for houseplants and are often found in greenhouses.
3. Echinotrips: This species has seen a strong rise in recent years and is increasingly an issue in covered cultivation. Echinotrips are most common in ornamental crops and are recognizable by their black color with a white stripe over the leaf.
4. Japanese Thrips: This is a relatively new species in the Netherlands, first detected in 2014.

Spread of Thrips

Thrips can spread quickly because they lay large amounts of eggs and have a rapid life cycle. Although they are not very good at flying, they are often carried by the wind, allowing them to spread easily to new areas.

The larvae of thrips go through several stages before they drop to the ground to pupate. There, they transform into adults ready to cause damage again to the plant.

Damage Caused by Thrips

Thrips cause damage by piercing into the cells of leaves and sucking out nutrients and sap. The damaged cells turn silvery or gold, and the excrement from the thrips is visible as small black dots on the underside of the leaves. Not only do thrips damage the leaves, but also the growing tips are affected. Damage to the growing tips can cause malformed flowers and color variations.

Control of Thrips

Dealing with thrips can be challenging due to their persistence and small size. Chemical control is often not effective because it does not reach the larvae in the ground or deep in the flowers. Moreover, adult thrips can easily lay eggs again after treatment.

Biological control is often the most effective method. This involves using trap plants to capture large numbers of adult thrips, and employing natural predators such as predatory mites and parasitic wasps to reduce the thrip population naturally.

Chemical control is, however, the easiest and most efficient method to get rid of thrips, especially if you want quick results. It is important to intervene in time before the infestation becomes too large.

Tips for Preventing Thrips

• Keep your plants healthy and ensure good air circulation.
• Regularly check for signs of thrips.
• Use trap plants to lure adult insects.
• Consider using natural predators as part of your integrated pest management plan.

With the right approach, you can effectively control the damage caused by thrips and prevent them from spreading further. By taking preventive measures and using a combination of biological and chemical control, you can keep an infestation in check and maintain healthy, vital plants.