No abstract

No abstract

Background: Irradiation is accepted as a phytosanitary treatment for horticultural products by many countries. Irradiation is a potential alternative to chemical fumigation for wood products; however, data supporting its efficacy against potential forestry pests is limited. Methods: Irradiation efficacy data were obtained experimentally for Arhopalus ferus (Mulsant) and Hylurgus ligniperda (F.). The results are compared to existing ionising-radiation treatment data for various bark and woodboring beetles species as found in the International Database on Insect Disinfestation and Sterilization (IDIDAS) and the published literature. Results: Existing IDIDAS records suggest that the effective dose required to sterilise insects in the families Cerambycidae and Scolytinae is < 150 Gy. Estimated LD 99 obtained here for the sterility of adult A. ferus were 44. 1 Gy (LD 99 , ± 15.3, 95% CI) and eggs 40.4 Gy (± 9.8, 95% CI). Our results suggest that an effective sterilisation dose for A. ferus eggs will be from 20 to 40 Gy; however, LD 99 dose estimates were not obtained for other life stages. Adult H. ligniperda were more tolerant of radiation with 1.6% of adults producing viable eggs at doses of between 100 and 150 Gy despite 100% sterility being recorded at 75 and 175 Gy. Conclusions: Our results are consistent with existing studies of other bark and wood-boring beetles. The doses tested here were equivalent to, or lower than, those used in previous studies. Arhopalus ferus adults were less tolerant to ionising radiation than the published literature for other Cerambycidae. Further studies with adult H. ligniperda are recommended as 150 Gy represents the upper limit currently reported in IDIDAS for other Scolytinae. An assessment of the potential cost-effectiveness of irradiation as a phytosanitary treatment at the range of doses identified in this study should be conducted before committing to further efficacy testing.

Early detection of bark- and wood-boring beetles is critical to support the eradication of recently established populations in novel regions. Flight intercept traps baited with semiochemical lures are essential for surveillance and population monitoring of introduced insects. We present laboratory and field data to test potential improvements in trap sensitivity to detect Hylastes ater (Paykull), Hylurgus ligniperda (Fabricius) (Coleoptera:Scolytinae), and Arhopalus ferus (Mulsant) (Coleoptera:Cerambycidae). We evaluated the effects of type and permeability of plastic material on release rates of host-plant volatiles and the addition of the pheromone racemic E-fuscumol on beetle species catch within an exotic Pinus radiata (D. Don) plantation forest. We trapped 228,278 H. ligniperda, 91 H. ater, and 2,504 A. ferus over two experiments. Our results show strong attraction of H. ligniperda to host-plant volatiles with a positive relationship between increased release rates and trap catch. H. ater follows this trend, with attraction to ethanol and (−)-β-pinene. H. ligniperda was more strongly attracted to host volatiles than H. ater, the average ratio between baited and unbaited traps being 51.25:1 and 3.75:1, respectively for each species. There was no effect of host-plant volatiles or release rate on A. ferus catch, but a weak attraction by A. ferus to racemic E-fuscumol. Overall, we demonstrate species-specific differences in Coleoptera attraction to host-plant volatile release rates and semiochemical blends. Results demonstrate mechanisms to improve trap catch of H. ligniperda and H. ater. Racemic E-fuscumol shows some promise for A. ferus, but further investigation is required to determine whether chirality affects attraction.