PATHOGENICITY OF METARHIZIUM ANISOPLIAE VAR. ACRIDU TO THE DEVEOLPMENTAL STAGES OF BROWN PLANTHOPPER NILAPARVATA LUGENS STÅL AND SOGATELLA FURCIFERA (HORVATH) |
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Authors: | Bo-wen Geng Run-jie Zhang |
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Institution: | State Key Laboratory for Biological Control, Sun Yat-sen University, Guangzhou 510275, China;Institute of Hydrobiology, Jinan University, Guangzhou 510632, China |
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Abstract: | Abstract The susceptibility and virulence of entomopathogenic fungus Metarhizium anisopliae var. acridum to the stages of brown planthopper (BPH), Nilaparvata lugens (Stål) and whitebacked planthopper (WBPH), Sogatella furcifera (Horvath) were investigated under laboratory conditions. Three dosages of M. anisopliae var. acridum ranging from 10.5, 116.3 and 1027.1 conidial/mm2 were used in the experiment. The tested stages of host included three developmental stages, young nymphs (1–2 instars), old nymphs (3–5 instars) and adults. It was found that all tested stages of the planthoppers were susceptible to the fungal infection. The degree of virulence LT50 of M. anisopliae var. acridum against young nymphs of N. lugens are >21, 20.82 and 16.55, respectively with the 3 dosages, the LT50 of the fungus against the old nymphs are 17.68, 15.49 and 13.98, respectively with the 3 dosages; the LT50 of the fungus against the adults are 17.10, 12.57 and 9.14 respectively with the 3 dosages. The degree of virulence LT50 of M. anisopliae var. acridum on young nymphs of S. furcifera are >21, 17.29 and 13.13, respectively with the 3 dosages ; the LT50 of the fungus against the old nymphs are 16.94, 15.02 and 13.03, respectively with the 3 dosages; the LT50 of the fungus against the adults are 12.78, 10.16 and 7.64, respectively with the 3 dosages. Adults were more susceptible to M. anisopliae var. acridum infection than their nymphs and the young nymphs were most resistant to the fungal infection. The cumulative mortality of each stage was dosage-dependent. Of all the developmental stages, WBPH was more susceptible than BPH to M. anisopliae var. acridum infection with the same dosages. |
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Keywords: | Nilaparvata lugens (Stal) Sogatella furcifera (Horvath) Metarhizium anisopliae var acridum susceptibility virulence developmental stages |
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