Turnip sawfly

Systematic position: Athalia glabricollis belongs to the order Hymenoptera and the family Tenthredinidae. This species is recognized as a significant agricultural pest, particularly in regions where intensive production of cruciferous (brassica) crops is practiced.

Host crops: This pest primarily targets plants in the Brassicaceae family. Its main hosts include rapeseed (canola), mustard, oilseed radish, turnips, and various cabbages. It also utilizes wild cruciferous weeds as alternative hosts, which can serve as a bridge for infestation into cultivated fields.

Biology and life cycle: The life cycle involves complete metamorphosis: egg, larva, pupa, and adult. Females deposit eggs into the leaf tissue of host plants. The larvae, often called false caterpillars, feed voraciously on the foliage. Pupation typically occurs in the soil within a silk cocoon, which is also the stage where the insect often overwinters.

Nature of damage and pest status: The larvae are responsible for the damage. Early-stage larvae create small holes in leaves, while older larvae can skeletonize the foliage, leaving only the primary veins. In severe cases of infestation, the plants can be defoliated entirely in a very short period, leading to severe yield losses or even complete destruction of the crop.

Control measures: Integrated pest management (IPM) is crucial for controlling this sawfly. Key measures include:

• Deep soil cultivation after harvest to destroy overwintering cocoons.
• Effective management of wild cruciferous weeds to eliminate breeding grounds.
• Regular field monitoring for egg masses and larvae.
• Application of authorized insecticides when population thresholds are exceeded during the growing season.