Potato fight Dorifora

Dorifora adult

The dorifora is a beetle of American origin, once it arrived in Europe it found no natural enemy and therefore spread, becoming a problem for crops. In the garden, it particularly attacks plants of the nightshade family, such as potatoes and eggplant.

This insect has several metamorphoses: from the egg to the larval stage until it becomes an adult. For the winter, it takes refuge underground, it emerges when the ground permanently exceeds 10-12 degrees, it is generally found in May in search of food.

An adult dorifora guided by smell is able to travel up to 300 meters to reach the solanaceous plants of which it is greedy, after eating it begins to fly, mates and lays its eggs on the underside of the leaves of a healthy plant.


Recognize larvae and adults

The dorifora is an insect that is easily recognizable :

  • The larva is very easy to spot on potato leaves: they are red to orange insects with swollen bellies, black heads and tubercles. Its dimensions are approximately 1.5 cm long. Dorifora larvae are most commonly found on the lower page of the leaf, but being quite large it is not difficult to identify them by checking the plant, also because they tend to congregate in groups.
  • The adult is slightly smaller than its offspring, usually about a centimeter long, and is characterized by a yellow body with black stripes, the shape is that of a typical beetle. In flight, it is more difficult to see the adults, but they are yellow and black insects that are very easy to identify.
  • The small yellow eggs end up attached to the leaves, like the larvae on the bottom page.

Damage caused by Dorifora

Dorifora larvae

This phytophagous beetle attacks nightshades, paying particular attention to potatoes, its favorite plant, and on the other hand to aubergines and tomatoes.

Both the adult dorifora and the larval insect feed on leaves, if allowed to proliferate in the garden, they can compromise the vitality of the infested plant and quickly defoliate the other Solanaceae present. When the insect is adult, it can easily move between plants and even from one field to another.

The cycle of the insect reaches two or three generations per year, the greatest damage is usually seen in May, with the first birth of the larvae.

Prevention of insect attacks

The only preventative system for dorifora is crop rotation. However, in the size of a small vegetable garden, this method may not give much result: if the potatoes are moved a few meters, the adult beetle will reach them without difficulty. For larger-scale crops, it is important not to repeat solanaceous plants in the same soil, so as not to attract dorifora.

Biological control of dorifora

Manual control . The fight against dorifora in a small organic garden is mainly done with manual controls, this very simple method works very well on the larvae, the important thing is to catch the infestation in time. If the plants are carefully inspected during the month of May, the first generation of newborn beetles can be intercepted and eliminated, keeping the insect under control without doing any treatment.

the voracious turkey . Turkeys are greedy for Colorado beetles and can help a gardener who has a small flock of them clear crops of these beetles.

The bait method . A good way to get Dorifers out of the area is to force an early growth potato plant, which needs to be kept warm, so that it forms in early May and can be brought into the garden. The dorifores will be attracted by this “scoop” and will infest the plant, which will serve as bait for us to find and eliminate the beetles.

insecticides . Pyrethrum, bacillus thuringensis and neem oil can be used as insecticides in organic farming against dorifora. All three treatments can kill dorifora and are allowed in natural crops. Pyrethrum has the defect of acting only by contact, it is not easy to find and strike adults, it is also a product which, although of natural origin, has toxicity and can also kill bees and ladybugs. Neem oil like pyrethrum affects by contact, it is less effective but also less toxic to the ecosystem. The bacillus, on the other hand, is only suitable for killing larvae, in these it is very effective in blocking their digestive system causing their death, while it has no effect on adult specimens. There are several strains of bacillus thuringiensis, the best for dorifora is the tenebrionis variety, but the more common kurstaki can also be used. It is a beetle that adapts well to insecticides, creating increasingly resistant offspring. This means that manual removal in May remains the best way to defend potatoes and other crops against dorifora.

Biological control methods. There are also two control methods that involve inserting natural agents hostile to the beetle into the environment: Beauveria bassiana an antagonistic fungus capable of causing the death of the insect, and Hymenoptera Edovum putteri which feeds on dorifora eggs and is therefore useful in stopping overgrowth.

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