What's eating my lemon tree 'meyer'?

Lemon 'Meyer' (a lemon–mandarin hybrid) shares most citrus pest problems: citrus leafminer damages new flush growth, brown soft scale and mealybugs colonise stems, and aphids cluster on shoot tips. Citrus gall wasp is a serious additional threat in warm climates (Australia, South Africa). Leafminer is the most universally frequent pest on new growth.

Silvery tunnels in curled young leaves on every new growth flush; repeated attacks stunt young trees. Oil spray applied at bud-swell of each new flush; prune out heavily affected shoots. Avoid excess nitrogen that encourages flushes.

Flat brown scales on stems and undersides of midribs; sticky honeydew and black sooty mould on fruit. Horticultural oil or insecticidal soap spray; wipe stems; biological control with Metaphycus parasitic wasps.

Woody galls form on new stems; repeated infestation restricts sap flow and reduces fruiting (serious in warm climates). Prune out galls before August (Southern Hemisphere) or before adult wasps emerge; seal cuts; do not compost galled wood.

Black colonies on shoot tips; leaf curl, bud drop, honeydew and sooty mould. Water-jet dislodge; insecticidal soap; promote natural predators; remove ant trails that protect aphid colonies.