Biology of the European oak borer in Michigan, United States of America, with comparisons to the native twolined chestnut borer

In 2010-2011, we studied the European oak borer (EOB), Agrilus sulcicollis Lacordaire (Coleoptera: Buprestidae), in Michigan, United States of America, and made comparisons with the native twolined chestnut borer (TLCB), Agrilus bilineatus (Weber). EOB adult flight began and peaked before TLCB. More EOB females were captured on purple and white compared with yellow and green sticky traps. More TLCB females were captured on purple, followed by yellow, green, and white, respectively. Male EOB and TLCB did not show a significant colour preference. EOB completed development primarily from areas of artificially girdled trees where the phloem had died soon after trees were girdled, while TLCB usually developed in areas of girdled trees that had some live phloem present. Both EOB and TLCB successfully attacked and emerged from girdled Quercus alba Linnaeus, Quercus robur Linnaeus, and Quercus rubra Linnaeus (Fagaceae) trees. No live EOB or TLCB were found in two ungirdled and apparently healthy Q. robur trees that were dissected. EOB attacked and emerged from Q. alba, Q. robur, Q. rubra, and Quercus velutina Lamarck trap logs. Differences in the pronotal groove and terminal processes can be used to distinguish EOB from TLCB larvae. Five species of parasitoids were reared from EOB and four from TLCB.