Selection of Beauveria isolates pathogenic to adults of Nilaparvata lugens.
The brown planthopper, Nilaparvata lugens Stål (Hemiptera: Delphacidae), is a destructive invasive pest and has become one of the most economically-important rice pests in China. Effective control measures are desperately needed. Entomopathogenic fungi, such as Beauveria bassiana (Balsamo-Crivelli) Vuillemin (Hypocreales: Clavicipitaceae) and B. brongniartii (Saccardo), have shown great potential for the management of some sucking pest species. In this study, to explore alternative strategies for sustainable control of the sucking pest population, nine isolates of Beauveria from different pests were bioassayed under the concentrated standard spray of 1000 conidia/mm(2) in laboratory. The cumulative mortalities of adults ranged from 17.2 to 79.1% 10 days after inoculation. The virulence among all tested isolates exhibited significant differences (at p = 0.05). The highest virulent isolate was Bb09, which killed 79.1% of the treated insects and had a median lethal time of 5.5 days. Its median lethal concentration values were estimated as 134 conidia/mm(2) on day 10. The chitinase activities of nine isolates were also assayed. The results showed that the chitinase activity (18.7 U/mg) of isolate Bbr09 was the highest among all tested isolates. The biological characteristics of these strains, including growth rate, sporulation, and germination rate, were further investigated. The results showed that strain Bbr09 exhibited the best biological characteristics with relatively higher hyphal growth rate, the highest spore production, and the fastest spore germination. The isolate of Bbr09 had strong pathogenicity and exhibited great potential for sustainable control of N. lugens.
School of Plant Protection, Anhui Agricultural University, Hefei 230036, Anhui Province, China These authors contributed equally to this work sj412bq@163.com.
Maoye
M
Li
School of Plant Protection, Anhui Agricultural University, Hefei 230036, Anhui Province, China These authors contributed equally to this work lsg815@163.com.
Shiguang
S
Li
School of Plant Protection, Anhui Agricultural University, Hefei 230036, Anhui Province, China xuameiahau@126.com.
Amei
A
Xu
School of Plant Protection, Anhui Agricultural University, Hefei 230036, Anhui Province, China hf.lin@163.com.
Huafeng
H
Lin
Qingzhou Tobacco Research Institute, China National Tobacco Corporation, Qingdao 266001, Shandong Province, China 13963973187@126.com.
Dexin
D
Chen
School of Plant Protection, Anhui Agricultural University, Hefei 230036, Anhui Province, China xuamei100@gmail.com.
Hui
H
Wang
D000818:Animals; D052982:Beauveria / Q000201:enzymology / Q000235:genetics / Q000254:growth & development / Q000502:physiology*; D002688:Chitinases / Q000378:metabolism; D005260:Female; D005656:Fungal Proteins / Q000378:metabolism; D006430:Hemiptera / Q000254:growth & development / Q000382:microbiology*; D008297:Male; D009758:Nymph / Q000254:growth & development / Q000382:microbiology; D010572:Pest Control, Biological; D013172:Spores, Fungal / Q000254:growth & development / Q000502:physiology
D005656:Fungal Proteins; D002688:Chitinases
biological characteristics; chitinase; microbial control; virulence