PLEASE inspect your citrus trees for lumps and bumps—they could be nests full of invasive wasp babies about to hatch.
The state agriculture department has issued a warning that citrus gall wasps are concentrated in Bayswater, Vincent, Stirling and further north in Bassendean and Swan.
Native to Queensland and the warmer regions of NSW, their nests look like little woody bulges (about 25mm thick) in citrus twigs and are teeming with infant wasps.
“Each gall contains hundreds of larvae which emerge as tiny black wasps during Spring from October to November,” Helen Newman from WA Citrus Biosecurity says.
The wasps can kill younger trees and stop mature trees from producing fruit.
If you find one of the nests, the best ways of disposal is like a scene from an 80s monster movie: The wasps can be killed by double bagging them in black plastic bags and leaving them in the sun for four weeks, or by shredding the wasps into tiny bits, or burning them, or burying them one metre below ground.
Also let the agriculture department know by calling 9368 3080, or by using their free pest reporter app, MyPestGuide.