Dr. Phyto

Sugar maple

Acer saccharum

Diseases & pests on this plant

• Tar spot of mapleRhytisma acerinum

  Late summer to autumn, raised, shiny black spots up to 2 cm across (like drops of tar) form on the upper leaf surface, sometimes surrounded by a yellow halo; heavily spotted leaves may drop early, but tree health is rarely affected.

• Spotted lanternflyLycorma delicatula

  Large planthopper (adults ~25 mm) with grey forewings dotted black and bright red-and-black hindwings; masses of insects on trunks, weeping sap, black sooty mould growing on the honeydew, and grey putty-like egg masses on bark, stone and outdoor surfaces.

• olive Verticillium wiltVerticillium dahliae

  Half a tree wilting in summer while the other half stays green, blackish discoloration in cross-section of affected wood, partial recovery in winter then relapse, dieback over 2–4 seasons.