They are not dangerous. On the contrary, they are as harmless as they are annoyingbut they will accompany us in the coming days to different regions of Navarre. It is known as boxwood moth and, according to observations and data analyses carried out by technicians from the Department of Rural Development and Environment, a “significant increase” in its presence in Navarre.
The boxwood moth is a invasive alien species which feeds on boxwood leaves causing damage to these plants. When the attack is strong, it can cause total defoliation and even death of bushes affected.
Defoliation caused by caterpillars is followed by Butterfly hatching expected in the coming weeks. “THE clouds of moths (adults) will be more visible in the affected area and surrounding areas, floating at night and approaching the artificial light sourcessince it is a very good flying species which can travel a long distance,” the government of Navarre underlines in a press release.
Boxwood is a shrub that is very present in a large part of the forests of Navarre, very resistant and with a great capacity for regrowth, so damage to the leaves normally only temporarily compromises the photosynthetic capacity of the shrub which can grow back later. But, during strong attacks, when the caterpillars lack food, they are able to nibble the bark of the twigs and even the trunk, causing more significant damage which weakens the plant and partially or completely dries out the aerial part of the boxwood.which then germinates from the roots.
Since its arrival in Europe in 2007 from Asia, this invasive alien species spread rapidly, affecting boxwoods across much of the continent. Since 2015 it has reached the Iberian Peninsula and spread through a large part of the Navarrese forestsTheir rate of progression in Navarre is very asymmetrical, further affecting wetlands than dry ones. There are periods in which it occurs very large enlargements in a short time then there are pauses, populations decline and damage is temporarily reduced. These trends may be related to the weather conditions of each year (‘normal’ years vs. dry, hot years).
In Navarre, the Boxwood forests abound northeast of Pamplona in the area between Aoiz, Longuida, Urraúl Bajo and Lumbier. According to the government of Navarre, It will not be difficult to spot them within a 20-kilometer radius of these cities.
In the case of bojedales that have suffered heavy attacks in previous years, “Most have shown signs of recovery important, recovering part of the initial foliage”. However, some cases of very damaged bojelados have also been observed, without the capacity to recover to the situation before the passage of the plague.
