How to Identify and Control Thrips in Crops

Photo Credit: Lyle Buss from the Univeristy of Florida

Vegetables form an integral part of our diet, with many nutritional benefits. For vegans, leaf, stem, fruit, and root vegetables are stable food. Unlike other food crops, they require small space and can grow indoors or outdoors.

Whether growing vegetable crops for your kitchen grocery or sale, one major problem you will often encounter is diseases and pest attacks. Thrips are among the common vegetable pests that attack crops grown indoors and outdoors.

Caution: If not managed early, their damage is fatal and can lead to huge losses.

You have more to learn about thrips control in your vegetable farm and how you can manage them once you see signs of an invasion.

Read on and find out more from this post.

What Are Thrips and How Do You Identify Them?

Thrips are tiny insects with sequined wings that appear in different colors. An adult thrip is about 1.5mm long and has six wings. When fully grown, thrips appear in different colors, including black, light yellow, brown, red, white, and orange. These minute insects feed on pollen, fungi, plant sap, mites, and insects.

You can easily spot them by their asymmetrical mouthparts and fringed wings. They are among the smallest insects and can be destructive.

Caution: If you are not keen, thrips can cause damage to your vegetables before you spot them.

Most farmers and gardeners spot thrips after they have done visible damage. Crops infested by these micro-pests have white and black patches, especially on the lower side of foliage, are less succulent, and turn white with time. Thanks to the many thrips control methods, you can still salvage your crops after the attack.

Note that these pests reproduce by laying eggs and can multiply fast. Therefore you should get rid of them immediately if you see signs of an invasion. Furthermore, they move from one host plant to another and can destroy a whole vegetable plantation.

Which Thrip Species Affects Vegetable Crops?

Many thrips species feed on plants. The common ones are bean flowers, cotton tips, onions, bananas, and western flower thrips. They attack crops from the nursery beds, after transplantation, when budding, and even after harvest.

How Do You Control Thrips in Vegetables?

Routine nursery and field practices such as weeding, thinning, and pruning are simple ways to manage pests. Some of these pests find hosts in weeds, and when you uproot them, you eliminate them. If you grow your vegetables indoors, keep your garden clean and your crops spaced to minimize infestation.

There are three main ways of managing and keeping thrips at bay.

Organic control

Thrips control organic methods are ways of getting rid of thrips without using chemicals such as pesticides and sprays.

You can manage thrips organically by:

1. Physical routine practices such as:

● Uprooting weeds and crop remains after harvest to minimize the pest harboring areas.

Tip: To keep your soil moist, use dry grass clippings to form mulch.

● Use overhead sprinklers to water your vegetable crops. The water jet washes away the thrips and can kill them.

● Keep your vegetable yard clean and well spaced to deny the insects' hiding places.

● Frequently inspect all plants and remove the infected ones.

● Pruning helps you spot and remove affected branches and limit the hiding place for pests in your crops.

● Covering young seedlings to control pests from patching on them. You can also cover the rows with dry grass to minimize hiding places for the pests since they don’t patch on dry grass.

● Use sticky traps which are scented and brightly colored to trap the insects. You can paint your trap with bright blue or purple paint and hang it strategically in an open area of your farm.

2. Biological practices:

Introduce insectivorous mites to your greenhouse or outdoor vegetable garden. The mites feed on thrips but are harmless to vegetable crops.

You can order predatory mites and bugs from commercial dealers.

Organic pesticides

Organic thrips control insecticides are prepared from plant extracts such as pepper and neem oil and animal products.

Most of these pesticides are non-poisonous to humans but can eliminate insects. Here are examples:

1. Smothering soap is prepared by mixing plant oil and fats. The oily soap forms a blanket on the pests, suffocating them.

2. Peppermint soap is prepared from caster oil and sodium hydroxide mixed with mint extracts. This soap has an antiseptic effect on pests though it is harmless to other insects. This soap is ideal for onion thrips control, especially those planted near grain fields.

3. Neem oil extracted from the neem tree is rich in phytochemicals that paralyze thrips before killing them. This thrips-control insecticide has many benefits for human health, such as healing wounds and keeping your skin smooth.

Chemical pesticides

Chemical insecticides for thrips control act more rapidly in eliminating these pests but can be poisonous to other beneficial bugs.

They are ideal for heavily attacked vegetable crops, especially those grown indoors. They include the following, among others:

● Horticultural oil from petroleum products offers the best thrip control in greenhouse vegetable crops. It is among the few mild chemical insecticides which are less deadly to the other beneficial insects on your farm.

● Natural pyrethrins extracted from chrysanthemum flowers, this chili thrips control is a combination of many poisonous extracts from plants. It kills most insects and pests in addition to thrips. This is not the best remedy for your yard if your vegetable crops are insect-pollinated.

● Organophosphates are strongly scented chemicals that inhibit the enzymatic action in the central nervous system hence killing the pests. Organophosphates are highly poisonous and can affect humans as well. You should only use this pesticide sparingly if more than one insect heavily infests your crops.

Final Thoughts

Unlike other crop pests, thrips can be challenging to detect early. You can manage them by inspecting your farm regularly and maintaining cleanliness. When choosing a method of managing and controlling thrips, start with organic control since it is less harmful to other beneficial insects and humans.