The beetle Capnodis tenebrionis (Linnaeus, 1758), receives the common name of Flatheaded Borer worm.
The plague, affects mainly the stone fruit (cherry , almond, plum tree, apricot tree, peach tree…).
The common name “Flatheaded Borer” receives it due to the shape of the larva, which is a white worm and large head.
Adults of Capnodis tenebrionis, feed especially on weak trees that have suffered water stress. This strategy helps to weaken the trees and promotes infection. In healthy and strong trees with good flow of sap the larvae drown and die.
Adult activity is visible mainly during the summer and early fall.
Initially they endeavor to weaken the fruit tree (cherry tree, plum tree, almond tree…). For this they cut the petiole of the leaf using its jaw. These attacks are easy to see if we take a look at the cherry plantation .
Adults who have spent the winter hibernating, make the laying during the dry weather of summer and early autumn.
The larvae are fed until they become adults
The adult Capnodis tenebrionis feeds on the leaves and buds of fruit trees. In addition, they cut the leaves to weaken the tree and facilitate the future survival of the larvae.
Although the most visual damage is produced by adults, the main damage is produced by the larvae.
The larvae feed on the xilema and cambium of the roots of the cherry tree by digging galleries that cut the flow of cherry sap. As a result, the Flatheaded Borer larvae weaken and usually end with tree death.
How to detect the Capnodis tenebrionis worm?
The easiest way to control adult stubborn worm activity is to look at the ground. When we see green cherry leaves on the ground. Most likely, the insect is on a nearby branch.
In young cherry plants it is easier to see them than in large trees, where their capture may be unfeasible. In addition, the beetle moves positioning itself in the angle of vision where it is more difficult to locate.
Once detected, we must be careful when picking them up, as they usually fall to the ground when they detect a threat. They also have wings and can fly, although they do not usually flee in this way.
Capnodis tenebrionis control
The best way to Capnodis tenebrionis control is to keep the trees healthy and strong, for this we must avoid situations of stress. The irrigation of support in situations of drought, the balanced pruning, the control of nutritional deficiencies…
The application of insecticide treatments during its diet (after harvesting cherry), to the soil during the sunset season or to the tree during the winter rest they help to fight the plague of the Flatheaded Borer.
The products authorized in Spain (october 2017) are:
Formulated based on Chlorpyrifos 25%: products with the trade names Warrior and Hoster.
Products with active material Imidacloprid 20%. We can find them in agricultural stores with the following trade names: Confidor 20 Ls, Dacoprid, Kohinor, Kopy, Couraze, Terrasita, Kosso, Clorprid 200, Mido, Confidante 20 Ls, Nuprid Insecticide, Llanero, Winner, Plural 200 Sl, Pritt, Nuprid, Shock, Imidor, Tiestes 200 and Imidachem.
Tiametoxam 25%: products sold under the brand Actara and Actara 25 Wg
In organic farming, the treatment to be applied consists of the use of natural emulsionable pyrethrins and gives good results.
Another way to control the big-worm attack is to place a double layer of synthetic fiber buried around the trunk. This layer prevents the larvae of Capnodis tenebrionis from reaching the roots of the cherry tree.
The products above, are authorized as of Octuber 2017 in Spain.
A significant part of the information, comes from Spanish research organizations. When phytosanitary products are used, it is important to verify that their use is currently authorized in the country of application.