The cherry tree borer is a plague that affects the cultivation of the cherry tree , almond, plum and other fruit trees of bone and nugget. It belongs to the genus of Coleoptera (beetles) and the family Scolytidae.
Among others, there are two different species of borer that affect the cherry tree and other fruit trees Scolytus rugulosus (Müeller, 1818) and Scolytus amygdali (Guérin, 1847).
Characteristics of cherry tree borer
Adults: have a length between 2 and 2.7mm. Its body is cylindrical and they have dark black color. Finally, there are no important differences between male and female.
Larvae: they are 2-3 mm long, are whitish in color and do not have legs (nicknames).
Eggs: have an elliptical shape, 0.7 mm long and white.
Note: cherry varieties less vigorous are more susceptible to the attack of this pest .
The cherry tree borer has two generations per year.
First generation: Larvae that have spent the winter, begin their adult transformation phase forming a pupa during the month of April. Adults begin to leave the galleries outside of May.
Before fecundating, the females penetrate the crust and make a chamber where mating takes place. The chamber between 2 and 3 cm in length serves for the laying of eggs, about 20 at each end. The females of barrenillo, have preference to realize the putting in branches of weakened cherry trees.
Adults make feeding galleries that affect tender shoots and may bouquets.
Second generation: usually takes place between the month of August and the end of summer, adults of the first generation mate and make a new laying that will spend the winter in a larval state.
Damage produced by the borer
The borer adult tend to feed on the branches and may clusters of vigorous trees. During this process they can dry productive parts of the tree reducing the harvest.
The larvae instead are parasites of weakness and like the bighead worm are best developed in sparse trees.
Consequently, the wounds produced during the feeding of the larvae usually exude sap of similar consistency to the gomosis.
In weakened plantations infected by cherry tree borer, the attack of the plague, can end up producing the death of the affected trees.
Treatments and cultural measures
The cultural and preventive measures are the most appropriate for the control of the disease. Keep the vigorous fruit trees with good subscribers, balanced pruning, treatments against other cherry pests and fungi. And if it is possible to carry out irrigations of support that avoid the hydric stress of the plantation. If we achieve a healthy plantation by controlling the diseases that weaken our crop, the borer should not be a concern.
In addition to the above recommendations, other suitable measures consist of the pruning and burning of infected branches.
Authorized treatments for the borer.
The chemical control is not usually very effective since adults are usually protected by the bark.
There are no authorized treatments directly. This is due to the fact that the borer is not a plague of great repercussion in commercial cherry plantations.
Deltametrin 2.5%: with 14 days of safety, it is used to control the cherry tree aphid. It is sold under the trade names: Deltaplan, Audace and Decis.
The products above, are authorized as of November 9, 2017 in Spain.