European plum sawfly

Systematic position: The European plum sawfly (Hoplocampa flava) belongs to the order Hymenoptera and the family Tenthredinidae. It is a significant pest of stone fruit trees, capable of causing substantial economic damage in commercial orchards and private gardens alike.

Affected crops: This pest primarily infests plums. However, it can also be found on damsons, greengages, and sometimes apricots. Its host range is limited to specific members of the Prunus genus, making it a target-specific pest in terms of monitoring and control.

Biology and life cycle: The insect overwinters as a mature larva inside a silk cocoon within the soil. Pupation occurs in the spring. Adults emerge during the flowering period of plum trees. Females lay eggs individually into slits made in the floral sepals. The larval stage lasts about 3-4 weeks before the larvae drop to the ground to pupate.

Nature of damage: Larvae cause damage by boring into young fruitlets. As they feed, they hollow out the fruit and consume the developing seed, which causes the fruitlets to shrivel and drop prematurely. A single larva can migrate between and destroy several fruits during its development, severely reducing the total yield.

Control measures: Integrated pest management (IPM) is crucial. Cultural practices such as soil cultivation under the canopy can disrupt pupation sites. Chemical control involves the application of insecticides targeting the adult stage or newly hatched larvae immediately after petal fall. Monitoring using white sticky traps is recommended to determine the optimal timing for intervention.