The olive pyralid moth
or Euzophera, has the scientific name (Euzophera pinguis Haworth, 1811). It feeds on the bark and wood of the olive tree, damaging the sap flows and weakening the olive trees. Its presence is not usually worrying thanks to the control by several insects that parasitize it.
It is a secondary pest that must be controlled, however it should not focus our attention. There are plagues of greater economic relevancesuch as Verticillium, repilo, olive fly, Colletotrichum sp in olives, Prays, olive mealybug, barrenilloB…
Stages of development of Euzophera pinguis
Egg: whitish initially, they change to pink over time. The form of the eggs is flattened, oval and reticular. Its size is only 1×0.75 mm.
The laying of eggs is done in a unit or in small groups. Adults select the areas where the bark of the olive tree is damaged (cracks caused by frost, pruning wounds, nodules of tuberculosis…).
Larval state: The larva is white, with a slightly yellowish or greenish hue. It manages to reach a size of about 2.5 cm. Make a gallery between the bark and the olive wood where it passes all its larval state and performs the chrysalis.
Chrysalis: Something reddish brown and is surrounded by a layer of little thick silk. The chrysalis is located at the end of the excavated gallery during larval development.
Adult: In adult form it is a gray-brown butterfly and 2-2, 5 cmof wingspan.
Annual generations of the Euzophera pinguis
Although they can be found as a general rule in all stages of development, the olive grove presents two annual generations differentiated.
The larvae that have spent the winter start it. During the month of February the phase of chrysalization begins. Between February and March the first adults begin to fly, being in April when the mating flights intensify.
In the month of April the first larvae appear, reaching their population peak during the month of May, moment in which the chrysalization is very small.
During the summer the activity of adults is reduced and with it the presence of new larvae is scarce.
At early September the larvae begin to pupate. The adults make their setting until mid-October, being less intense than the spring.
Duration of generations
The approximate duration of the first generation is about 4-5 months (between May and October). On the other hand, the second generation of Euzophera has a cycle of 7-8 months.
Damage caused by Euzophera
The Euzophera or olive grove, produces wounds of different consideration during its larval feeding phase.
The wounds produced by the subcortical galleries performed by the olive grove result in the weakening of the branches or the trunk affected that can dry out.
The most important attacks occur in young plantations with important wounds on the trunks (usually caused by frost). Pruning olive treesduring the period of maximum laying of adults (April-May and October) also facilitates infection.
Control and treatment of olive grove
The natural predation usually carries out an effective control of the pest, however, when the olive trees have wounds on the trunks, the application of phytosanitary treatments may be necessary.
This is essential to avoid the use of insecticides that can damage parasitic populations.
The parasitic hymenoptera Iconella myelolenta and Phanerotoma ocularis perform an important control that exceeds 50% of the larvae.
Reduction of pruning wounds, avoid sunburn on the trunks and improve the vigor of trees (especially after frost or hail damage). The graft junction zone can also be an entry point.
The tuberculosis-sensitive varieties are more susceptible to laying, especially when wounds occur as a result of hail.
Chemical control of olive grove
The eradication of Euzophera pinguis is unfeasible when insects are found at different stages of development and are protected by the bark.
The most effective action is to attack the newly born Euzophera larvae during the months of greatest sunset (April, May and October).
The mixture of organophosphorus insecticides and summer oil is effective when performed on less hot days. The application must be done at low pressure and only wetting the laying areas (trunk and main branches of the olive tree. We must ensure that the products used are They are currently authorized for this purpose.
We have translated the information on our website from Spanish to English. Note that some words may have seen their meaning altered during their translation.