Scots pine borer
It attacks mainly Scots pine, although in some cases it can be found in other conifers.
The cycle begins in spring, when adult individuals that have spent the winter in hibernation begin to look for trees to colonize. The male looks for a pine tree, once this work is done, he begins to emit a pheromone to attract the females, which will make their own galleries, from this initial hollow, where they will deposit their eggs.
Ips acuminatus is a small coleopteran (beetle), initially brown in color but darkening with age to almost black. They reach a size between 2.5 and 4 millimeters, slightly less in females. The larva, completely white except for the brown head, also reaches this size before pupating. The abdomen ends abruptly in a flattened, gusset-like area surrounded by six teeth (three on each side), darker in males.
The reproduction method of this small beetle involves the opening of galleries under the bark of the tree that cut the vessels through which the sap circulates, weakening it. In addition, these beetles have the ability to emit pheromones that attract other conspecifics, concentrating and multiplying the damage, ultimately causing the death of the colonized trees and spreading to neighboring trees. The arrangement of the galleries under the bark allows us to know which species of beetle is doing the damage; in the case of the Scots pine borer they are star-shaped.