Elm Cockscomb Galls

Aphid Galls Rising on Elms

The leaves of native elms can look a bit bedraggled at this time of the year owing to the rise of pouch-like elm sack galls and the descriptively named elm cockscomb galls. Fortunately, neither of these aphid galls produce significant injury to the overall health of their elm tree host. Unfortunately, these odd-looking plant structures can spoil the aesthetics of their deep green elm leaf platforms.
Published on
Authors
Joe Boggs

Woolly Aphids on American Elm

Thanks to the sharp eyes of Dave Bienemann (Municipal Arborist/Utility Forester, City of Hamilton), I was able to take some nice pictures of the woolly apple aphid (Eriosoma lanigerum) and it's characteristic damage on its alternate host, American elm (Ulmus americana). This isn't the only woolly aphid that uses our native elm as an alternate host. The woolly elm aphid (E. americanum) is another historical American elm pest.
Published on
Authors
Joe Boggs

Bedraggled Elms: Galling Conditions

The leaves of native elms can look a bit bedraggled at this time of the year owing to rise of pouch-like elm sack galls and the descriptively named elm cockscomb galls. Fortunately, neither of these aphid galls produce significant injury to the overall health of their elm tree host. Unfortunately, these odd looking plant structures can spoil the aesthetics of their deep green elm leaf platforms.
Published on
Authors
Joe Boggs