La White fly it is a small winged insect of about 2-3 mm. that affects many of our vegetables.
They like heat and humidity so it is a pest of the summer outside and all year round indoors or in the greenhouse.
It lives in groups on the underside of leaves, where it lays eggs. The larvae and adults suck the sap from the leaves. The leaves yellow, are covered with a sticky substance and they end up falling.
Many times a black mold, the Black Fungus, which uses the sticky and sugary substance as a seat, and dirties and prevents the photosynthetic function of the leaves.
El pest control can be done with certain chemical treatments or by biologic control introducing a tiny parasitic wasp (Encarsia formosa) into its environment. But I suggest an alternative: hang sticky yellow traps between the vegetable garden that attract the males. It is easy to find in garden centers and does not cost more than one euro for an 8 x 20 cm strip.
And as a measure of prevention, it gives very good result plant aromatic, Chinese carnations, marigolds or ornamental tobacco along with the most sensitive species. Its aroma repels whiteflies.