Rose sawfly

The rose sawfly (Allantus calceatus) is a member of the Hymenoptera order, specifically belonging to the Tenthredinidae family. It is a well-known pest that specializes in attacking various species of roses and plants within the Rosaceae family, making it a significant concern for both garden enthusiasts and commercial growers.

The primary host plants include garden and wild roses, as well as plants of the genus Rubus, such as raspberries and blackberries. These plants provide the necessary nutrients for the larvae to complete their development, making them vulnerable to infestation during the active growing season of the host.

The life cycle of Allantus calceatus consists of egg, larva, pupa, and adult stages. Females lay their eggs into the leaf tissue, usually near the veins. Once hatched, the larvae, often referred to as sawfly larvae, begin to feed voraciously on the leaf foliage, progressing through several instars before pupating in the soil.

The damage caused by the larvae is characterized by the skeletonization of leaves and the appearance of irregular holes, which can eventually lead to complete defoliation. This severe foliage loss weakens the host plant, resulting in reduced vigor, poor growth, and a significant decrease in the quantity and quality of flower production.

• Manual removal of infested leaves to eliminate eggs and young larvae.
• Cultivating the soil around the base of the bushes in autumn to destroy pupae.
• Application of insecticidal soaps or systemic pesticides for major infestations.
• Encouraging natural predators such as parasitic wasps and birds into the garden.

Effective management requires consistent monitoring of the plants from early spring onwards. By catching the early stages of the infestation, gardeners can significantly reduce the population of the sawfly and prevent it from causing widespread damage to their rose collections throughout the remainder of the summer.