Seasonal biology and management of the maple shoot borer, Proteoteras aesculana (Lepidoptera: Tortricidae), in production nurseries

BACKGROUND: Proteoteras aesculana (Riley), a caterpillar that causes tip dieback and kills the central leader of maples, is an important nursery pest. The authors sought to develop a pheromone lure, use it to clarify the pest's seasonal biology, determine when and where infestations originate and extend the management window. RESULTS: Gas chromatography, electroantennographic detection and trapping showed that (Z)-dodec-8-en-1-ol (Z8-12:OH) is the major sex pheromone component. Flight began in March, peaking in early spring. Larvae developed during April and May, giving rise to moths active in late May and June. No additional larvae were found in maples following that flight. Sporadic moth captures occurred into November, suggesting that adults overwinter. Three parasitoid species, all new host records, were documented. A different tortricid, Episimus tyrius Heinrich, caused leaf-tying damage in late summer. Maples shipped from Oregon were free of shoot borers, refuting speculation that larvae overwinter in buds. One bifenthrin spray applied from just before bud break at onset of moth flight to just after peak flight when shoots had two pairs of leaves reduced infestation by 96-100%. CONCLUSION: Maples are infested soon after planting in Kentucky nurseries via eggs laid in early spring. The temporal window for preventive control is broader than previously thought.