Characterisation of a Malawian isolate of Beauveria bassiana, a potential control agent of coffee stem borer, Monochamus leuconotus.
The radial growth, sporulation and viability of a Beauveria bassiana isolate were assessed at three temperatures (23, 28, 33 degrees C) under light and dark conditions. Optimum radial growth and sporulation occurred at 23 degrees C regardless of photoperiod with the highest spore concentration being attained after incubating for 28 days. Loss of viability was highest at 33 degrees C and there was no significant loss in viability at 23 degrees C for up to five weeks. It would appear that 33 degrees C is too hot for the sporulation, growth and viability of this insect fungus. Photoperiod effects were insignificant for all the parameters evaluated. The infectivity on white coffee stem borers at 2.5 x 10(8) spores ml(-1) was high with 100% of the test larvae immobilised and not feeding within 24 h and dying within two to twelve days.
Kutywayo
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V
CAB International-Africa Regional Centre, Nairobi, Kenya. vhukilek@hotmail.com
Karanja
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L
Oduor
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G
Nyirenda
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S
D000818:Animals; D052982:Beauveria / Q000502:physiology*; D003069:Coffee / Q000469:parasitology*; D001517:Coleoptera / Q000254:growth & development*; D008295:Malawi; D010572:Pest Control, Biological / Q000379:methods*; D017440:Photoperiod; D013172:Spores, Fungal / Q000254:growth & development / Q000502:physiology; D013696:Temperature; D013997:Time Factors
D003069:Coffee