What's eating my tasmanian blue gum?

Tasmanian Blue Gum (Eucalyptus globulus) is targeted by eucalyptus longhorned borers, snout beetles (Gonipterus), and gall wasps. The biggest threat is the longhorned borer, whose larvae tunnel into the cambium and can kill a tree within weeks. Keep trees healthy through proper watering and avoid wounding bark.

Larvae bore beneath the bark into the cambium, disrupting water and nutrient flow; wilting foliage, branch dieback, and oozing sap with sawdust-like frass are telltale signs. No effective chemical control for homeowners once larvae are inside. Prevention is key: keep trees well-watered and avoid wounding. Remove and chip infested wood promptly.

Adults and larvae feed on leaves, causing ragged, notched edges and defoliation of young shoots. In most areas the egg-parasitic wasp Anaphes nitens provides near-complete biological control. No pesticide intervention is typically needed or effective for home gardens.

Larvae induce hard galls on leaves, stems, and petioles, causing distorted growth and reduced vigour on young trees. Prune and dispose of heavily galled material. Maintain plant vigour with irrigation and fertiliser; established trees tolerate moderate infestations. No widely available home chemical control.