Our laburnum trees are being attacked by caterpillar type pests. They eat the leaves. At first we notice black small spots on the leaves and then they turn into these pests that look like caterpillars. Tried malthanion, soap water etc.
They do not attack any other trees nearby
What can be done ?
The scotch laburnum tree is vulnerable to caterpillars.
Products based on Bacillus Thurengiensi are authorized for use in organic growing and only have a very reduced negative impact on our planet.