Four-spotted sawfly

The four-spotted sawfly (Cimbex quadrimaculata) is a member of the Cimbicidae family within the order Hymenoptera. Despite its interesting appearance, it is recognized as a notable agricultural pest that specifically targets temperate fruit trees in various regions.

This pest primarily attacks fruit-bearing trees including apple, pear, plum, and other Prunus species. The larvae are voracious feeders that specialize in foliage, which can lead to significant canopy damage if the infestation is not monitored and managed in a timely manner.

The life cycle involves four distinct stages: egg, larva, pupa, and adult. The adults typically emerge in the spring, and after mating, females insert their eggs into the leaf tissue. Larvae develop through several instars, feeding on leaves throughout the summer months before descending to the soil to pupate.

The primary damage is caused by the larvae consuming leaf tissue. They can skeletonize leaves or consume them entirely, often leaving only the main veins. A heavy infestation can cause severe defoliation, which severely stresses the tree, reduces its ability to produce fruit, and hinders growth.

Effective management requires a combination of strategies. Cultural practices, such as tilling the soil beneath the canopy, help disrupt the pupation process. Chemical control using selective insecticides is often necessary when larval populations exceed economic thresholds. Regular monitoring during the spring is essential for early detection.