Yellow Poplar Weevils on Poplar and Magnolia
We just got an alert from Amanda Taylor, Area Specialized Agent – Nursery and Greenhouse, that yellow poplar weevils, Odontopus calceatus, are active in WNC. I have started to seen them here in the Piedmont as well. Yellow poplar weevils can occasionally be severe pests of tulip poplars and magnolias growing in nurseries and landscapes. They are present throughout the state and throughout the east where ever their hosts grow wild. Adults are blue to black with a long snout.
The adults overwinter in leaf litter under host trees. On warm spring days they fly up and feed on buds and leaves. In May and early June eggs are laid in a row inside the midrib. After hatching, the grubs mine the leaves and cause blotch mines. Usually the blotch starts near the tip of the leaf. When ready to pupate, grubs move to an inflated portion of the mine and spin a spherical silk cocoon that soon turns brown. The inside of the mine is filled with strings of silk and frass. A new generation of adults emerges in mid June. By mid July the adults have disappeared to their hiding places in leaf litter and will remain inactive until spring.
Insecticides available for leaf-feeding beetles can be used if significant damage is expected or cannot be tolerated. There are a number of insecticides labeled for nursery and landscape use in the Southeastern US Pest Control Guide for Nursery Crops and Landscape Plantings.