whitewash or whitefly It is a plant parasite of tropical origin, with a behavior very similar to that of aphids, with which it is related. These flies indeed they feed on plant sap with production of molasses and the consequent possibility of soot .
Whiteflies, also called aleirodidae, are not picky eaters and can be found on many types of garden and orchard plants, such as tomatoes and hot peppers.
For this reason they can become a big problem if they infest the garden, when an attack is detected it is good to intervene quickly, also because the whitefly is characterized by a very fast reading which facilitates its spread.
In fact, the so-called white fly or greenhouse fly is not a single species, there are different strains mosquitoes which can also infest horticultural plants.
Damage caused by whiteflies
Which crops are affected
Recognize the presence of the insect
Defend the garden against whiteflies
Biological insecticides against whiteflies
Preventing Whitefly Attacks
Like aphids, aleuroditas usually settle on the sheet footer from there they damage the leaf and secrete the characteristic sweet honeydew, which can then cause soot Is viral infection to plants. Therefore, the damage to vegetables is mainly in the transmission diseases , indirectly. The insects are small and the sap they suck causes little direct damage. When they are numerous, they can further weaken the plant to the point of causing its leaves to fall and die.
Which cultures are concerned?
The aleirodid is a polyphagous insect , does not hesitate to move from one plant to another and is much less selective than aphids. In addition to vegetables, it can infest many ornamental plants and does not disdain the young branches of trees in the orchard. There is a variety known as citrus whitefly It mainly affects citrus planting, as its name suggests.
This crop pest likes the closed and protected environment of the tunnel and for this reason often attacks vegetables in greenhouses, not in vain one of the commonly attributed names is precisely ” greenhouse fly “. In winter, the whitefly can settle in winter between the inner leaves of the cabbage which provide shelter until spring.
Recognize the presence of the insect
The Aleurodidae are easily recognizable: they are very small but still visible to the naked eye, usually whitish . They often settle under the leaves, at the bottom of the page , so they remain hidden from the distracted eye, just like aphids. However, they are flying insects unlike aphids when it is watered plant whitefly individuals take flight and reveal themselves.
the white fly fear of cold therefore its incidence is lower in winter and generally in the north, while proliferates in temperate zones, greenhouses and citrus groves in the north it is mostly found in spring and summer.
In extensive horticultural crops, especially those grown in greenhouses, it is advisable to place chromotropic traps for monitoring purposes . This allows to detect the presence of the parasite at an early stage and intervene before it develops.
Defend the garden from the whitefly
Pesticides should not be used against whiteflies: there are several natural defense methods that avoid the use of dangerous treatments. Let’s find out in detail what practices and products we can use.
The whitefly is similar to aphids but it is a winged insect, which means that the technique consisting in washing the small parasites from the leaves or removing the parts of the affected plant has limited effectiveness: if it eliminates easily eggs and larvae, adult individuals move more easily from plant to plant. However, on a small scale, it is worth manually intervening to eliminate the pests when they are numerous.
biological insecticides against whiteflies
This insect is quite resistant to insecticides and is also able to adapt to an active ingredient over time, so for the treatments to be effective it would be important to vary the product.
Besides it is not easy to kill the whitefly with a natural contact product like all organic pesticides, because small insects hide under the leaf and often escape treatment.
Among the products authorized in organic farming, the following can be used to kill whiteflies:
sweet orange essential oil
Among the vegetable macerates that can be self-produced is the repellent effect of garlic and chilli macerate .
Whiteflies can be caught with chromotropic traps which hang in the garden above infested plants and function as fly paper.
This system is useful for both surveillance and mass capture, but you have to be very careful. because by catching whiteflies you can reap innocent victims among beneficial insects. Especially if there are flowering plants, you should avoid using sticky traps of this type.
To fight against whiteflies, it is also possible to launch a biological fight using the encarsia formosa , a small wasp that lays its eggs among those of the whitefly and is a natural antagonist. In addition to the wasp, entomopathogenic fungi can also be used: the beauveriabassiana and the verticilliumleumlecanii they can work. These remedies are feasible on a medium and large scale, it is not recommended to use them in a small orchard. However, even in the home garden, you can hope to attract a very common whitefly predator: ladybugs.
Prevention of whitefly attacks
In addition to biological control proper, it is useful to try to prevent the presence of this pest, especially in tunnel crops, which are particularly harassed by whiteflies. To avoid the arrival of the whitefly inside the greenhouses, it is good to ventilate frequently let in the cold which is not welcome for the insect.
Another form of prevention is to attract ladybugs to your garden, as already explained, they are natural fly predators.
Finally, if you look plants that often harbor whiteflies elimination is worth considering, especially species that provide a winter refuge in which to overwinter.