WHILE the Cook Government works out how to manage polyphagous shot-hole borer (PSHB) to minimise the impact of shot-hole borer on Perth’s tree canopy and help protect the state’s horticultural industries it might help if Swan and Perth Hills residents get to know more about which plants are susceptible.

When the government abandoned trying to eradicate the pest Department of Primary Industries and Regional Development’s (DPIRD) deputy director general Mia Carbon said determining factors included the difficulty in detecting and controlling new borer infestations at an early stage before the pest could reproduce and the current lack of effective chemical treatments available for killing the borer.

Dr Carbon said DPIRD would lead the transition to management in WA to minimise the impact of shot-hole borer on Perth’s tree canopy and help protect the state’s horticultural industries.

“This decision does not mean that the national response to shot-hole borer has stopped.

“The response will enter a new phase that focuses on longer-term management of the pest.

“Over the next 18 months, DPIRD will work with industry, community and local government to build skills, knowledge and capacity to manage the pest long term.”

DPIRD has posted a PSHB host list but also said many plant species in WA remain of unknown PSHB susceptibility so regular referral to the host list, which is updated frequently was advised.

The list names reproductive host tree species proven to support Polyphagous shot-hole borer (PSHB) reproduction and allowing the growth of the associated Fusarium sp. [AF18] fungus, which serves as a food source for the beetle offspring.

The most highly susceptible reproductive hosts are preferred by PSHB and infestations have been confirmed multiple times, typically associated with moderate to heavy infestation.

Trees with extreme susceptibility are box elder maple, coral and robinia (mop top robinia, black locust).

Introduced trees with very high susceptibility are poinciana, common fig, Chinese hibiscus, white mulberry, London plane tree, castor oil and Chinese wisteria.

Australian natives with very high susceptibility are river sheoak, Moreton Bay fig, Port Jackson fig and wedding bush.

Western Australian natives with very high susceptibility are swamp paperbark, sea hibiscus and cottonwood.

Introduced trees with high susceptibility are orchid tree, angel’s trumpet, golden shower tree, mirror bush, honey locust, ice-cream bean, golden rain tree, sweet gum, liquardambar, mango, weeping mulberry, black mulberry, avocado, callery pear, English oak, Humboldt’d willow and Chinese tallow.

Australian natives with high susceptibility are Illawarra flame tree, Moreton Bay chestnut, weeping fig, Green Island fig.

Western Australian natives with high susceptibility are Broome raintree, lebbeck tree, swamp bansia, marri, red flowering gum and stout paperbark.

Introduced species with moderate susceptibility are copperleaf, trident maple, orchid tree, Caucasian boxwood, common camellia, carob, queen of the night, night jessamine, bitter orange, Seville orange, Tahitian lime, Cape wedding flower, Kei apple, song of India, dracaena, golden dewdrops, African coral tree, rubber tree, rubber fig, mulberry fig, narrow-leaf ash, kaffir plum, dwarf umbrella tree, confederate rose, Japanese privet, lychee and southern magnolia.

More introduced species with moderate susceptibility are American sycamore, common poplar, Simon’s poplar cherry plum, Lusitanian oak, Durmast oak, loquat, weeping willow, corkscrew willow, western soap berry, Brazilian pepper-tree,  Wych/Scots elm, Wych/Scots or flied elm, Japanese wistaria, wisteria, zelkova and Japanese elm.

Australian natives with moderate susceptibility are golden wattle, Bangalow palm, Illawara palm, diamond-leaf pittosporum, kurrajong, bottle tree, sugar gum, southern blue gum, South Australian blue gum, yellow gum, swamp mahogany, silky oak, Australia umbrella tree, macadamia nut, paperbark, creek bottlebrush and lilly pilly.

Western Australian natives with moderate susceptibility are acorn banksia, narrow-leave bossiaea, swamp sheoak, karri, flooded gum, banbar, ricinocarpus bridal star, wedding bush, basket bush and western woody pear.

There is also a list of non-reproductive host tree species that can be attacked but do not support PSHB reproduction.

In these trees the beetles cannot establish breeding galleries, the fungus may or may not cause disease and trees are generally not expected to die.

Visit https://www . dpird.wa.gov.au/sitea ssets/documents/biosecurity/incidents/pshb/pshb-wa-host-list.pdf