Eficiency of new isolates of entomopathogenic fungus Beauveria bassiana against RPW, Rhynchophorus ferrugineusin Saudi Arabia [electronic resource].

Includes references.

The red palm weevil Rhynchapharus ferrugineus is a destructive pest on date palm plantations in the Middle East. Traditionally chemical insecticide have been used to control this insect in the Arab region .Arab Organization for Agriculture deveiopment (AOAD) set up a project to use bioagents to control this pest. seven local strains of entomopathogenic fungus Beauveria bassiana were salated from naturally infected red palm weevils adults, pupae and from an adult of the mole cricket Gryllatalpa sp. for the first time in Eastern province, Saudi Arabia. Bioassay of three Isolates, B-SA1, B-SA2 and B-SA3 on R. ferrugineus adults resulted values LC50 of 1.25x107 ,1x105 and 2x106 conidialml. Adults allowed to contact food sprayed with a formulation of conidia of B-SA3 and oil\water of the concentrations of 30,20, 10,9,5 x 108 (conidia /ml) for three days showed 100% death in insects. however, 2.5 and 1.25 x 108 \ conidia /ml) killed 50 and 57 % of the rpw. 100 % aerial fungus developed on insects at the concentrations of 30 and 20 x 108 conidia Iml . Only 75,60 , 50 , 50 and 12.5 % of the insects showed aerial growth of the fungus resulted from concentrations of 10, 9 , 5, 2.5 and 1.25 x 108 conidia Iml respectively . Stored dray conidia at - 4 C for 16 months, indicated 98.5 % germination during the first 6 months, then declined to 88 % up to the month 13. Germination of stored dray conidia for 14 to 16 months exhibited 74 and 61 % germination respectively. Effect of sunlight on the germination of the dray conidia during a period of 15 days exhibited reduction in germination from 95 .7 after one day to 91.2, 86.4 75, 70.7 and 67.57% at days 3,6,9,12 and 15 days respectively .Regration line showed that the half life of the fungus is about 22 days.

Summary in Arabic.

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