USDA, ARS, SEL F-519915 
Figure 211.—Resin masses caused by Figure 212.—Damage to paper birch by 
feeding activity of larvae of the cecidomyid, Apagodiplosis 
Cecidomyia resinicola. papyriferae. 
The willow beaked-gall midge, Mayetiola rigidae (Osten Sacken), produces 
apical, beaked galls on the lower branches of many species of willow (fig. 213). In 
Michigan, eggs are laid singly on or near the buds of the host. Newly hatched larvae 
penetrate the bud and a gall begins to develop by the end of the first instar and 
continues to enlarge until fall. Winter is spent as a larva inside the gall, and 
pupation occurs in the spring. The gall deforms the stem and occasionally a galled 
branch dies or breaks off (/328). 
F-519914 
Figure 213.—Gall produced on willow by 
the willow beaked-gall midge, 
Mayetiola rigidae. 
elt 
