ERADICATION OF INSECT PESTS OF SUBTROPICAL AND TROPICAL FOREST PRODUCTS WITH FREEZING STORAGE

Eradication of insects inside imported timber or forest products remains a challenge for quarantine/plant protection authorities in preventing incursion of exotic pests to a country. Quarantine treatment options such as fumigation are often not effective owing to the presence of impervious layers/finishes (paints). Seventy naturally-infested Acacia parramattensis and Acacia decurrens timber branches collected during summer from tropical/subtropical Australian region and termite-infested timber and timber blocks inoculated with Bostrichidae beetles were subjected to freezing between -18 and -25 °C for 1 to 14 days. Samples were removed from the freezer at the end of each time interval between 24–360 hours. Removed samples were destructively sampled to determine presence of live/dead insects inside each sample. The insects recovered from the samples belonged to the families Cerambycidae, Bostrichidae and Scolytidae. None of the insects/larvae were found alive after receiving the initial freezing treatment of 24 hours. No adults emerged from the samples that were preserved at room temperature for a further 90 days. All insects in control samples remained alive throughout the experiment. This study has shown that freezing can be used as a quarantine treatment to control or eradicate timber pests present inside imported timber or forest products of tropical and subtropical origin.