Related Experiment Video
Updated: May 3, 2026
Isolation and Selection of Entomopathogenic Fungi from Soil Samples and Evaluation of Fungal Virulence against Insect Pests
Published on: September 28, 2021
[Screening for virulence strains of Metarhizium against Dorysthenes hydropicus pascoes]
Wei-Si Ma1, Hai-Li Qiao1, Xiang-Qun Nong2
1The Key Laboratory of Bioactive Substance and Resources Utilization of Chinese Herbal Medicine, Ministry of Education, Institute of Medicinal Plant Development, Chinese Academy of Medical Science & Peking Union Medical College, Beijing 100193, China.
Objective:
The aim of the present study was to screen the Metarhizium strains with high virulence against the larvae of Dorysthenes hydropicus, a serious pest of Citrus grandis.
Method:
Thirty six strains of Metarhiziums were isolated from the soil of C. grandis GAP base and collected from other institutions, and the pathogenicity of these strains against 1st instar larvae of D. hydropicus was detected at concentration of 1 x 10(8) conidia/g. The high violence strains against D. hydropicus were cultivated in sabouraud dextrose yeast medium at first, then transfer to rice grain. And the sporulations of these violent strains against D. hydropicus were detected.
Result:
Twenty-eight strains showed virulence against D. hydropicus by preliminary study, and 7 strains of them were collected for further study, 6 of the 7 showed high virulence, the highest cadaver rate was higher than 74%. The conidia production of strain 1 and strain 4 were 2.35 +/- 0. 25 (1 x 10(9) conidia/g), 2.21 +/- 0.27 (1 x 10(9) conidia/g), respectively, showed significantly higher than other strains.
Conclusion:
Strain 1 and strain 4 of the 36 Metarhiziums strains showed high virulence against D. hydropicus, and the highest sporulation ability, so they have a best application prospect.
Insights
Two Metarhizium strains demonstrated high virulence against Dorysthenes hydropicus larvae, a significant citrus pest. These strains also exhibited superior sporulation, indicating strong potential for biological control applications.
Area of Science:
- Agricultural Entomology
- Microbial Pest Control
- Plant Pathology
Background:
- Dorysthenes hydropicus is a major pest affecting Citrus grandis (pomelo).
- Biological control agents offer sustainable pest management strategies.
- Metarhizium species are known entomopathogenic fungi with biocontrol potential.
Purpose of the Study:
- To screen Metarhizium strains for high virulence against Dorysthenes hydropicus larvae.
- To identify Metarhizium strains with significant insecticidal activity for pest control.
Main Methods:
- Isolation and collection of 36 Metarhizium strains from Citrus grandis soil and other sources.
- Pathogenicity assays of Metarhizium strains against 1st instar larvae of D. hydropicus at 1 x 10(8) conidia/g.
- Cultivation of virulent strains and assessment of their sporulation on rice grain.
Main Results:
- Twenty-eight of 36 strains exhibited preliminary virulence against D. hydropicus.
- Six out of seven selected strains showed high virulence, with the highest causing over 74% mortality.
- Strains 1 and 4 displayed significantly higher conidia production (2.35 x 10(9) and 2.21 x 10(9) conidia/g, respectively).
Conclusions:
- Metarhizium strains 1 and 4 possess high virulence and sporulation capabilities against D. hydropicus.
- These selected strains show promising application prospects for the biological control of this citrus pest.
