Pecan Carpenterworm – Cossula magnifica

Pecan Carpenterworm (Cossula magnifica) Latin Name: Cossula magnifica Common Name: Pecan Carpenterworm Appearance: Adult: Moth with brown and black spots on a greyish background. Forewings have little brown patches and a wide brownish region at the distal end; hindwings are uniformly darker and lack distinguishing markings. The wing span varies between 37 and 44 mm. Larva: Pinkish and bare, or sparsely coated with small, fine setae emerge from tubercles. The head, cervical shield, and anal plate are all a gleaming dark brown. Mature larvae can grow to be 37 mm long. Pupa: Brown with strong projections on the head, which it uses to force its way through the pupal cell and down the larval tunnel until it reaches the escape hole. Host plants: This borer attacks pecan, oak, and hickory. Territory: The southeastern United States is home to this borer. Damage caused by Pecan Carpenterworm: The majority of attack sites are centered on the base of the trunk from the groundline up to roughly 1.2 m. Because infected branches might be high above ground and frass spreads as it falls, warning indications are sometimes overlooked. Frass in the shape of pellets accumulates in mounds on the ground around the roots of infected trees. Life history and Habits: Adult moths deposit their eggs on the bark of tiny branches near treetops. Newly born larvae begin by burrowing the pithy cores of little twigs and branches. Larvae leave branch galleries in early fall, migrate downward, and bore into the trunk and major branches. Larvae attacking tree trunks commonly start galleries in bark cracks and tunnel upward 13 to 32 mm horizontally or obliquely, then vertically for another 6 to 13 cm. Mature larvae widen the entry pores in April or May, then enclose themselves at the top ends of the galleries behind threadlike material networks. The species’ life cycle is unknown; however, it appears to have a single generation every year.