Thrips are tiny insects, similar to very small wasps, white, green, yellowish or brown in color, equipped with a stinging-sucking mouthparts. The adult specimens of these insects survive the winter by hiding on the ground, among the dry leaves or in the bark mulch; as soon as the climate becomes favorable, and the nocturnal lows begin to rise, the adults of thrips rise on the plants, generally during flowering, and the females lay their eggs directly inside the buds. The larvae develop around the fruitlets, and becoming adult they spread on the foliage, or on other plants. A second generation is produced in late spring, making the insects present until late summer; in general the most affected plants are those in the orchard, such as peach trees and vines, but many infestations are noticed in spring also on ornamental plants grown in greenhouses. There are various insects called thrips, belonging to different genera; the most common and common thrip is Frankliniella occidentalis, together with heliothrips haemorroidalis, and Taeniotrhrips meridionalis; the first is typical on ornamental plants and from the garden, the others prefer vines and fruit trees.
In general, in commercial orchards and vineyards, the products used against other insects, or even against fungal diseases, tend to contain the attack of thrips, which tend not to show very large infestations. Despite this, it can happen in particular years that thrips grow in large numbers, ruining buds, buds, leaves and fruits.The common insecticides, those also used against aphids, also work against these small flies, or at least they contain the population in an excellent way.It also appears that rain watering tends to drop most of the eggs, making the populations less aggressive and containing the number. In any case, it is always advisable to check the number of thrips present in the greenhouse, in the garden or in the orchard, to prevent them from infesting our plants they are also vehicles of very harmful virosis or bacteria.The product that seems to hit these insects best, decimating its population is called Spinosad; it is an insecticide obtained from a bacterium naturally present in the soil; although it is therefore a product of natural derivation, it is effective against many insects, in particular against thrips, larvae of various types, beetles, lepidoptera, and therefore has a wide spectrum of action. If used correctly it is not toxic to humans and small animals, but it remains an insecticide that can be deadly to bees and aquatic animals, such as small fish or water turtles, and therefore should be used only in the evening hours, or when there are no flowers in the garden, keeping at a safe distance from waterways and ponds. We remind you, however, that insecticides should be used following the instructions on the label, and you should never overdo the doses and frequency of treatments. In general, treatments against steep slopes are carried out only a couple of times a year; more treatments would only lead to the killing of other insects, which can be useful in the fight against harmful insects.Many other insecticidal active ingredients have proven to work very well in the fight against thrips.Insecticides of natural origin
The concept of organic is often confused with the concept of natural; agriculture in general is a natural and biological activity, since it is a question of stimulating and following the development of living beings, whose fruits are caught, in Italy with organic farming we mean an agriculture that tends to avoid the use of synthetic products, derived from the chemical industry, or even genetically modified products and organisms. In the Anglo-Saxon speaking countries, the same concept is called organic agriculture; the meaning is the same: it is about cultivating the land trying to avoid impoverishing its nutrients, and avoiding inserting external elements, such as insecticides and pesticides, into the natural biological cycle, which impoverish the biodiversity of agricultural land.
So fruit and vegetables from organic farming generally contain low amounts of pesticides or pesticides, because the philosophy of organic farming uses methods other than the use of synthetic products to contain the attacks of harmful insects.
For example, a widely used method, which is gradually being implemented over the years, consists in containing the presence of harmful insects, introducing useful, antagonistic insects into the fields. Typical example of ladybugs, which are used to fight cochineal; or even the sexual pheromone traps, which are used to trap some harmful insects (typically beetles or moths), instead of killing them by spreading harmful chemical substances in the air or on crops, which are sometimes derived from nature, but are not necessarily harmless.
Most common thrips
Thrips are a genus of plant pest insects but they are not all the same and differ according to some characteristics as well as according to the plants they attack. Here is a list of the main thrips that can be interesting for those who love agriculture and gardening and want to prevent these insects from attacking their plants.
Known as citrus and greenhouse thrips, this thrip with the scientific name Heliothrips haemorrhoidalis is one of the most widespread varieties of this insect family and perhaps the one that causes the most problems. With its small size (its body does not exceed 1.5 mm) and its dark black body, the citrus thrips can be recognized by their light legs and the last segments of the body which have a paler color, tending to reddish brown . The Heliothrips haemorrhoidalis has narrow and long wings and usually attacks the green parts of plants where it inflicts punctures that together with the deposition of excrement by this insect, causes a necrosis (rot and blackening) of the leaves. These thrips can be found most often on the underside of the leaves where they remain for most of the time and where they begin to do damage.
The damage of these insects on the Citrus fruit is mainly noticed on the fruits of citrus fruits, such as oranges and lemons, where they are seen as a result of the bites of insects of the suberifications and rusty spots.
The citrus thrips need warm environments to live and for this it is found more easily in the Mediterranean areas and in greenhouses, where in addition to citrus fruits it can also attack other plants. In these environments the thrip does more damage as it is active all year round not having to go on diapause in winter.