Oberon Shire Council passed a recommendation late last month to cease using imidacloprid, otherwise known as Silvashield or Confidor, on all but its most damaged elms and the remaining 260 trees should be treated in more environmentally-friendly ways, including taping trunks. 

It followed bans in American, European and Asian countries after the insecticide was linked to major drops in native bee populations. 

Elm beetles eat elm tree leaves, causing heavily damaged foliage to drop early and potential loss of the tree - Orange's trees were badly affected in 2017. 

However, Orange City Council spokesman Nick Redmond said the parks and gardens team in Orange used the insecticide in line with its own research and experiences of other councils across southeastern Australia. 

"If trees were sprayed, any passing insect could be affected. If the soil was soaked, underground insects or insect larvae could be affected," he said.

"We do neither of those steps, we inject the treatment into the trunk - that way only insects that eat the leaves, such as elm leaf beetles, are affected."

Mr Redmond said the chemicals were approved for use in Australia and stem injection occurred when the first sap started to move in early spring.

"Elm trees are wind pollinated and flower in late winter when bee activity is low," he said. 

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