If we were to include the insects that cause the most trouble in our crops, we would surely consider including thrips (specific case of Frankliniella occidentalis ) in this list .
The tisanosptera known as thrips or spider mites, very small insects that feed almost exclusively on our plants and carry viruses. Today, in Gardenprue, we dedicate the article to Frankliniella occidentalis .
If we talk about the order tisanoptera ( Thysanoptera ) we would have to mention the 5,600 species that make up this group.
Among them, special attention should be given to Frankliniella occidentalis, especially because of its importance as a pest and virus vector of many essential crops, such as tomatoes.
Among this wide order, there are two characteristic species that every farmer should know:
- Frankliniella occidentalis or western flowers thrips.
- Thrips tabaci or onion thrips .
Here is its biological cycle:
The main way to detect the presence of thrips is by searching the flower buds. Another way is to find silver spots on the leaves as a product of the suction of this insect and the reaction with its saliva.
Freshly set fruits are also damaged by nymphs, on which the typical silver spots also appear.
Damage to ripe fruit caused by P. kellyanus. Photo. A. Tena
THE TOMATO TAN VIRUS
One of the vectors of the tomato tan virus (TSWV) is Frankliniella occidentalis. This is because it injects saliva and introduces it into the sap when it sucks up plant content.
Even so, although it is called tomato tanning, it is not exclusive to this nightshade, since it also attacks other important crops such as pepper, lettuce, cabbage, aubergine, strawberry, etc.
BIOLOGICAL CONTROL OF FRANKLINIELLA OCCIDENTALIS
If there is a notable genus of insects that effectively control thrips, it is the Orius . They are heteropterans of the Anthocoridae family that are also used to control populations of Tetranychus urticae (red spider) and whitefly.
It has the advantage that Orius is not a rare species that must be introduced into our crops, since it is established by itself as long as there is a balance of populations (in many cases this is not the case due to the disproportionate use of insecticides).
Usually the release occurs when the flowering of the crop begins. If we carefully inspect a flower we can see how Orius preys thrips (or chases it). On the contrary, it is sensitive to common insecticidal applications that are carried out on crops, such as the active ingredient imidacloprid .
ORIUS RELEASE INSTRUCTIONS
When the first thrips are detected, it is time to release this predator. There are also farmers who prefer to release them just when flowering begins without the presence of thrips or Frankliniella occidentalis yet .
The loose ones are made on the leaves, leaving them to act for a few days. At that moment the reproduction and development of the insect begins. It is also interesting to apply carefully in those foci where the presence of thrips in abundance has been detected.
The good thing about Orius, among other things, is that it preys on more enemies than it can eat and can be incorporated into a wide variety of crops and plants.
CONTROL OF FRANKLINIELLA OCCIDENTALIS BY TRAPS
The use of traps, although not a proper control mechanism, helps to reduce the density of thrips and, above all, to estimate or quantify the danger of the pest.
One of the most used traps for Frankliniella occidentalis is the chromatic trap. What color is the most attractive? Well, there are diversity of opinions. Some studies defend that the white color is effective to control thrips, especially Frankliniella occidentalis.
Others defend the use of yellow traps (which is also used for other species), and others the blue color.
CHEMICAL CONTROL OF THRIPS
For those who take advantage of chemical means to care for their plants, there are various active ingredients that are effective against this pest. However, better than mentioning them and taking into account their short expiration period and the continuous supervision to which they are subjected, we prefer to leave you a link with the active materials that you can use, according to the Spanish Ministry of Agriculture.
+ Chemical control of Frankliniella occidentalis
+ General chemical control for tisanoptera