Native Borers and Emerald Ash Borer Look-alikes (E2939)DOWNLOAD FILE
February 11, 2016 - Author: Mary Wilson
Native Ash Borers
Native ash borers are North American insects that tunnel under the bark of ash trees, sometimes causing enough damage to seriously weaken trees.
These two borers attack healthy ash trees:
Banded ash clearwing, Podosesia aureocinto; adult (Fig. A), larva (Fig. B)
Ash/lilac borer, Podoesia syringae; (Fig. C).
- Wasp-mimicking moths that feed on xylem of ash trees.
- Larvae are round with legs and expel frass from tree (Fig. D).
- Round exit hole (1/4 inch); pupal case exposed in exit hole upon emergence (Fig. E).
These three borers attack stressed or dying ash trees:
Redheaded ash borer, Neoclytus acuminatus; adult (Fig. F), larva (Fig. G).
Banded ash borer, Neoclytus caprea; adult (Fig. H).
- Longhorned beetles (roundheaded borers) that attack stressed ash trees, but also colonize elm, hickory, oak, linden, and others.
- Larvae tunnel deep into xylem (Fig. I) and adults emerge from round-oval exit holes measuring 1/4 inch (Fig. J).
Eastern ash bark beetle, Hylesinus aculeatus; adult (Fig. K).
- Cylindrical bark beetle that forms galleries beneath the bark of ash trees (Fig. L).
- Infested trees peppered with tiny, round exit holes measuring approximately 1/16 inch (Fig. M).
Emeral Ash Borer Look-alikes
The following insects are common to Michigan and could possibly be confused with emerald ash borer.
- Six-spotted tiger beetle, Cicindela sexguttata; adult measures 1/2 inch long (Fig. N).
- Caterpillar hunter, Calosoma scrutator; adult measures 1 inch long (Fig. O).
- Japanese beetle, Popillia japonica, adult measures slightly less than 1/2 inch long (Fig. P).
- Bronze birch borer, Agrilus anxius; adult measures approximately 1/2 inch long (Fig. Q).
- Two-lined chestnut borer, Agrilus bilineatus; adult measures approximately 1/2 inch long (Fig. R).
- Several other uncommon metallic wood-boring beetles.