What is the cabbage butterfly
Cavolaia is a moth of the Pieridi family, originating in Europe, Asia and Africa, very widespread in Italy, where it can be pushed up to an altitude of 2300 m. In its adult form it is a diurnal cream-colored butterfly, with the tips of its dark wings. In the female two dark spots also appear on the upper part of the wings and a black dash towards the middle of the lower edge. The wingspan varies between 50 and 60 mm. Nine different species can be found. There Cabbage major (Pieris Brassicae) and the Cabbage minor (Pieris Rapae) are the best known. Both types have larvae that are deadly enemies of all gardening lovers because of their voracity in quickly devouring cabbages, turnips, cauliflower, radishes and cabbage. We see their biological cycle and how to protect our gardens from their attacks.
The biological cycle
Eggs, pupa, larva, butterfly: this is the biological cycle of the cabbage butterfly, which is repeated up to 4 times each year. The eggs, yellow in color, are visible on the underside of the leaves on which they have been deposited. From these eggs the larvae will be born, of yellowish green color with black spots. The larvae are 30 to 40 mm long and blend well with the vegetation. Although present all year round, their appearance peaks from March to November. In winter, in fact, this insect remains in the form of a pupa hidden in the ground and then rises again when the temperatures rise. The larvae reached maturity incalidate and then give life to adults, who in turn will deposit new eggs. The main flickering occurs between April and May and between June and July.
The danger for our gardens derives from the larvae of cavolaia, which dig tunnels and damage the leaves of all the crucifers: cauliflower, cabbage of any type, broccoli, turnips, radishes ... In a very short time they devour entire leaves leaving only the rib. Moreover, their droppings penetrate the plant making it inedible. To combat the larvae of cavolaia you can use traditional chemical insecticides such as products based on Imidacloprid and Deltamethrin, or chemical agents such as Bromophosma, Phosphamidone, Carbaril, Malation or Acefate. There are also biotechnological insecticides such as Essaflumuron. However, these systems are harmful to the ecosystem and should only be used in the presence of large infestations. Natural remedies to combat cabbage are in fact numerous and equally effective.
Cabbage damage: Natural remedies
Using natural methods it is first of all possible to try to prevent cabbage infestation. It may be useful to plant plants with repellent effect near cruciferous plants, such as mint; or use the help of antagonist insects such as hymenoptera or diptera. Weeding the soil instead allows the pupae to be eliminated before they turn into larvae. If, however, the cabbage plant has nevertheless managed to proliferate, it is advisable to harvest the eggs and larvae by hand. Alternatively, the tomato, wormwood and elderberry macerates are effective for their elimination. It is also possible to try with a bacterium, Bacillus thuringensis, which can be purchased already prepared in commercial preparations. For the cabbage butterfly there is a natural insecticide based on pyrethrum, but it must be used with caution because it kills both harmful and useful insects.