Trisetacus juniperinus

Mayetiola carpophaga

Cupressatia thujae

A juniper berry mite, Trisetacus quadrisetus Thomas

Damage: The mite attacks berries of juniper and prevents normal development. Hundreds of mites feed in each berry, causing it to develop in a shrivelled form instead of a smooth, round berry.

Host: Juniperus scopulorum

A spruce seed midge, Mayetiola carpophaga (Tripp)

Damage: Each larva feeds in and destroys a single seed.

Host: White and possibly other spruces.

A red cedar cone midge, Phytophaga thujae Hedlin

Damage: Mature infested cones are usually smaller than uninfested cones. Damage is visible externally after larvae have fed for a few weeks.

Hosts: Western red cedar

Cone and Seed Insects of British Columbia