Apple seed chalcid

Systematic position: The Apple seed chalcid (Torymus druparum) belongs to the order Hymenoptera and the family Torymidae. Unlike many other members of its family, which are parasitoids of other insects, this species has evolved into a specialized phytophagous pest that feeds specifically on the seeds of pome fruits.

Affected crops: This pest primarily attacks pome fruits such as apples, pears, and occasionally rowan or serviceberries. It is a significant issue in orchards where seed development is critical, as the larva's activity directly targets the reproductive potential of the fruit.

Biology and life cycle: The insect typically completes one generation per year. Larvae overwinter inside the seeds of mummified or fallen fruit. In the spring, they pupate, and adult wasps emerge during the period when fruits are beginning to form. Females use their long ovipositors to pierce the young fruit and deposit eggs into the seeds.

Nature of damage and economic impact: The damage is largely internal and often goes unnoticed until harvest time. Infested fruits may become deformed, stunted, or drop prematurely. The larvae consume the entire kernel of the seed, which ruins the fruit's quality and can lead to significant yield losses in susceptible varieties.

Control measures: Managing the Apple seed chalcid requires an integrated approach to minimize population levels. Recommended strategies include:

• Collecting and destroying fallen fruit regularly to eliminate the overwintering larvae.
• Cultivating the soil beneath the trees to disrupt the pupation process.
• Applying insecticides targeting the adult stage during the window of peak emergence.
• Monitoring the infestation levels to determine the optimal timing for protective sprays.