Raspberry Crown Borer

Raspberry crown borer Common name Raspberry crown borer Causal agent Raspberry crown borer is a tiny, black and yellow-colored insect belonging to the genus Pennisetia. The larval stage of the insect is responsible for the damage. Although the damage is not severe, continuous infestation can reduce yield. Scientific name Pennisetia marginata Symptoms & Signs Raspberry cane borer larvae bore a tunnel in the roots, crowns, and canes, containing saw-dust-like frass. It weakens the canes, which causes them to break off easily, especially from the crown. The leaves also show signs of slow growth, wilting, and dying. Due to damage to roots, the entire plant displays reduced vigor and yield. Time of concern Spring Common hosts Black Raspberry Blackberry Boysenberry Loganberry Red Raspberry Salmonberry Thimbleberry