WHAT ARE THE THRIPS?

Thrips are a pest insect that affects various crops of vegetables, such as cucumbers, watermelons, tomatoes, zucchini and onions. Next, we will give you more information about how to identify this pest, its life cycle and some recommendations to control it.

source

WHAT DAMAGE CAUSES?

These insects have wings, they are tiny and it is usually necessary to use a magnifying glass to observe them in detail. Thrips belong to the order Thysanoptera, have wings in their adult phase and are so small that their average length is 1.3 millimeters.

More than nine species of thrips are known that directly affect crops or plants of agronomic importance. For the conditions of Mexico, the following species are the most important: The western thrips of the flowers (Frankliniella occidentalis), which affects very diverse crops; the thrips of the onion (Thrips tabaci), which mainly harms the Allium family (onions); and finally, Heliothrips haemorrhoidalis, which is found in greenhouses and harms ornamental vegetables, plants and flowers.

source

Thrips feed on the contents of the leaves of our crops sucking with their mouth in the form of a sucking needle, and cause the formation of scars on the leaf and deformation in its growth, damage in the form of yellowish, white or silver spots on the leaf. surface of the leaf, as well as waste in the form of small black dots, which are the excrement of these insects. Here are some images of the damage caused by thrips to identify it:

Scars thrips

Scars caused by thrips and waste (excrement). Image: Jack Kelly Clark, UC Statewide IPM Project, University of California
Virus transmitted by thrips in tomato

source

In addition, this pest can cause aesthetic damage to the fruits, such as coppery or yellowish spots, and affect pollination, since some species also feed on the pollen of the flowers, therefore, it could decrease the fruit set and our expected yield.

Finally, thrips are transmitters of viruses and some fungal diseases. It is known that onion thrips (Thrips tabaci) and western thrips (Frankliniella occidentalis) transmit tomato tanning virus (TSWV), which causes yellowish spots on foliage, ring-shaped fruits and causes dwarfism on plants .

Another virus transmitted by this insect is the tobacco mosaic virus (TMV) when thrips feed on pollen from a diseased plant and come into contact with another. This disease causes deformations in the leaves, yellowing, and can cause leaf and fruit necrosis.

THRIPS MANAGEMENT.

To diminish the potential of damage of this plague in our crops, we offer you the following recommendations:

• Perform constant monitoring to identify if there are thrips in our crops and evaluate the level of infestation.
  Eliminate weeds around the plot, as many host this harmful pest and then move to vegetables.

• Use yellow sticky traps, as this color attracts them and stays stuck. This measure is more effective if it is done in the greenhouse. In the open field several of these traps can be placed on poles or wooden poles raised to approximately 50 centimeters.

• Ensure that the state of the plants is the ideal, with a fertilization, irrigation and control of other suitable pests, since the trips will cause more damage in stressed plants.

• Use plastic padding if possible, and opt for a reflective color like shiny silver.

source