We’ve heard a lot about them in the past few years The Oak Processionary Caterpillar, nobody loves them, most people hate them…but what to do about them. According to the anti-pesticide network “ Ouni Pestiziden”, Luxembourg's Ministry of the Environment, Climate and Sustainable Development recently issued permits authorising the use of a pesticide to combat the oak processionary caterpillar. This doesn’t sound great, as we all strive to be more environmentally friendly.
In recent years, the massive spread of the oak processionary caterpillar in Luxembourg, especially in recreation and settlement areas, has many people worried. Climate change favours the development of this species, which has spread in Central Europe. The caterpillars have stinging hairs, which can cause skin irritation or irritation of the respiratory tract upon contact. Due to the weather conditions but also the increase in predators, the populations were then decimated again. A decline in populations was also observed in many places in Luxembourg in 2020. In some places, the trend was supported by measures to promote natural predators such as tits.
Municipalities as well as foresters and representatives of the Environment Ministry, have come to the conclusion that control of the species with pesticides is inevitable. In fact, Foray ES can be used very selectively. If used carefully, only oaks would be sprayed, whereby species such as the red underwing (Catocala nupta), the dark crimson underwing (Catocala sponsa) or toothed spinner (Drymonia) would still be affected.
However, it is unlikely that only oaks will be hit, thus significantly expanding the range of endangered species. Killing the caterpillars and moths results in a lack of food for birds and bats. Accordingly, this leads to a decimation of the natural enemies of the caterpillar or the butterfly, andin turn this leads to a cyclically increased reproduction of the caterpillars in years to come.
Typically, larvae hatch from the 1mm eggs of the oak processionary moth between the end of April and the beginning of May. These larvae are difficult to spot on large oaks.
The selectively, but over a large area by evaporating from the ground. During the application and up to eight hours after using the agent of choice, it is advisable to avoid the affected area. The network thus argued that, particularly in extensive recreation areas and in the immediate vicinity of the settlement area, it is difficult to protect residents and their properties from the aerosols during and after application.
The anti-pesticide network insists it is not possible to use the agent safely and selectively without harming other organisms. It thus advised removing the caterpillars, at the earliest possible stage, using mechanical methods such as suction. In addition, the promotion of natural predators through the installation of nesting aids and other measures would enable a natural balance to be established in the long term. On much-visited paths and places, temporary barriers may still need to be set up if necessary. The network's end goal is to prohibit the use of pesticides in general in order to "successfully protect people, biodiversity and their future".