Laboratory evaluation of pathogenicity of Beauveria bassiana strains against Brontispa longissima Gestro (Coleoptera: Hispidae)

ABSTRACT

The coconut hispine beetle, Brontispa longissima Gestro, is an invasive and economically important pest of palm trees in China. Beauveria bassiana has been used widely to control agriculture and forestry pests, for example, Dendrolimus punctatus Walker, Pantana phyllostachysae Chao, and Basilepta melanopus Lefevre. Until now, there is no published data on the use of B. bassiana against B. longissima. In this study, we identified highly pathogenic B. bassiana strains against different developmental stages of B. longissima under laboratory conditions. The BB-01 strain presented the highest virulence against B. longissima. After inoculating with the BB-01 strain at (1.0 ± 0.5)  ×  10⁷ spores·mL⁻¹for 10 d (28 ± 1°C with 95 ± 1% relative humidity), the corrected mortality of B. longissima adults reached 94.7% with a LT₅₀ of 5.3 days. Mortality on other developmental stages was 84.4 ± 3.3% (LT₅₀ = 5.8 d) for 1st-2nd instars, 76.1 ± 1.2% (LT₅₀ = 6.71 d) for 3rd-4th instars, 73.7 ± 1.1% (LT₅₀ = 6.98 d) for ≥5 instars, respectively. BB-01 median lethal concentrations (LC₅₀) against 1st-2nd instar, 3rd-4th instar, ≥5 instar larvae and adults for 6 d were 9.0 × 10⁶, 3.5 × 10⁷, 4.8 × 10⁷, 9.1 × 10⁵ spores·mL⁻¹, respectively. The BB-01 strain exhibited a lethal effect peak on B. longissima at 6–7 d after treatment. This study provides basic data about the pathogenicity of different B. bassiana strains on B. longissima.

KEYWORDS:

• Biological control
• entomopathogenic fungus
• mortality-time probability method
• invasive pest species
• time-dose-mortality model

Acknowledgments

This work was supported by Science and Technology Bureau of Xiamen (No. 2014S0172), and Fujian Forestry Bureau (No. 201703). We are grateful for the assistance of all staff and students in the Key Laboratory of Integrated Pest Management in Ecological Forests, Fujian Province University, Fujian Agriculture and Forestry University, Fuzhou, Fujian, China.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Data Availability

The [DATA TYPE] data used to support the findings of this study are included within the article. And the RAW DATA are stored in supplementary files.

Additional information

Funding

This work was supported by Fujian Forestry Bureau: [Grant Number No. 201703]; Science and Technology Bureau of Xiamen: [Grant Number No. 2014S0172].