Laboratory and field evaluation of selected isolates of Metarhizium anisopliae and Beauveria bassiana against the leaf beetle Epilachna indica Mulsant

Yusof Ibrahim, . and Tan Gek Kiang, . and Cheong Chee Kong, . Laboratory and field evaluation of selected isolates of Metarhizium anisopliae and Beauveria bassiana against the leaf beetle Epilachna indica Mulsant. 15-. ISSN 0128-9322

Six isolates of selected entomopathogenic fungi were tested for their efficacy against the eggs larvae and adults of the ladybird beetle Epilachna indica (Mulsant) under an ambient environment of 28 20C 85 15 RH and 12 h photoperiod. All Metarhizium anisopliae were isolates were infective against the eggs larvae and adults of E. indica. Exposure to a suspension of 1 x 108 conidia ml-1 resulted in 99.2 - 91.5 infection on the eggs 71.7 - 65.0 on the 1st instar larvae and 86.7 - 76.7 on the adults seven days after treatment (7-DAT). Probit analysis showed significantly positive relationship between log dosage and probit mortality values with isolate MaOr providing the best estimated median effective concentration (EC50) of 9.268 x 103 conidia ml-1 against the eggs and 2.855 x 106 conidia ml-1 against the 1st instar larvae with estimated median lethal time (LT5o) value of 4.9 days while isolate MaPs gave the best EC5o value of 1.486 x 10 5 conidia ml-1 with LT5o pt value of 7.0 days against the adults. Infectivity by Beauveria bassiana was rather weak with the highest infection (54.5) on the eggs being inflicted by isolate BbPc while the highest against the 1 st instar larvae (58.3) by isolate BbGc and that against the adults (40.0) by isolate BbPc. In general isolates of M. anisopliae inflicted the highest mortality against the eggs larvae and adults of E. indica. Field experiment showed M. anisopliae (MaPs) and Deltamethrin were equally effective and inflicted significantly higher larval mortality (75.0 and 98.0 respectively) and lesser leaf damage (81.4 and 78.6 respectively) compared to B. bassiana (BbGc) and the control five days after the last spray.

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Abstract

Six isolates of selected entomopathogenic fungi were tested for their efficacy against the eggs larvae and adults of the ladybird beetle Epilachna indica (Mulsant) under an ambient environment of 28 20C 85 15 RH and 12 h photoperiod. All Metarhizium anisopliae were isolates were infective against the eggs larvae and adults of E. indica. Exposure to a suspension of 1 x 108 conidia ml-1 resulted in 99.2 - 91.5 infection on the eggs 71.7 - 65.0 on the 1st instar larvae and 86.7 - 76.7 on the adults seven days after treatment (7-DAT). Probit analysis showed significantly positive relationship between log dosage and probit mortality values with isolate MaOr providing the best estimated median effective concentration (EC50) of 9.268 x 103 conidia ml-1 against the eggs and 2.855 x 106 conidia ml-1 against the 1st instar larvae with estimated median lethal time (LT5o) value of 4.9 days while isolate MaPs gave the best EC5o value of 1.486 x 10 5 conidia ml-1 with LT5o pt value of 7.0 days against the adults. Infectivity by Beauveria bassiana was rather weak with the highest infection (54.5) on the eggs being inflicted by isolate BbPc while the highest against the 1 st instar larvae (58.3) by isolate BbGc and that against the adults (40.0) by isolate BbPc. In general isolates of M. anisopliae inflicted the highest mortality against the eggs larvae and adults of E. indica. Field experiment showed M. anisopliae (MaPs) and Deltamethrin were equally effective and inflicted significantly higher larval mortality (75.0 and 98.0 respectively) and lesser leaf damage (81.4 and 78.6 respectively) compared to B. bassiana (BbGc) and the control five days after the last spray.

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Item Type:	Article
Additional Information:	4 tables
AGROVOC Term:	ENTOMOGENOUS FUNGI
AGROVOC Term:	EPILACHNA
AGROVOC Term:	METARHIZIUM ANISOPLIAE
AGROVOC Term:	BEAUVERIA BASSIANA
AGROVOC Term:	INOCULATION
AGROVOC Term:	BIOASSAYS
AGROVOC Term:	MICROBIAL PESTICIDES
AGROVOC Term:	MALAYSIA HONGOS ENTOMOPATOGENOS
AGROVOC Term:	EPILACHNA
AGROVOC Term:	METARHIZIUM ANISOPLIAE
Depositing User:	Ms. Suzila Mohamad Kasim
Last Modified:	24 Apr 2025 06:26
URI:	http://webagris.upm.edu.my/id/eprint/21185

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