%D 2011 %0 MEDLINE %T Evaluation of alternative rice planthopper control by the combined action of oil-formulated Metarhizium anisopliae and low-rate buprofezin . %J Pest Manag Sci %V 67 %P 36-43 %A Jin SF %A Feng MG %A Ying SH %A Mu WJ %A Chen JQ %M pub20949549 %X BACKGROUND : High resistance of brown planthopper ( BPH ) Nilaparvata lugens Stal to common insecticides is a challenge for control of the pest An alternative control strategy based on the combined application of fungal and chemical agents has been evaluated . RESULTS : Three gradient spore concentrations of oil-formulated Metarhizium anisopliae ( Metschnikoff ) Sorokin ( Ma456 ) were sprayed onto third-instar nymphs in five bioassays comprising the low buprofezin rates of 0 , 10 , 20 , 30 and 40 microg mL ( -1 ) respectively . Fungal LC ( 50 ) after 1 week at 25 degrees C and 14 : 10 h light : dark photoperiod decreased from 386 conidia mm ( -2 ) in the buprofezin-free bioassay to 40 at the highest chemical rate . Buprofezin ( LC ( 50 ) : 1647 , 486 and 233 microg mL ( -1 ) on days 2 to 4 ) had no significant effect on the fungal outgrowths of mycosis-killed cadavers at the low application rates . The fungal infection was found to cause 81% reduction in reproductive potential of BPH adults . In two 40 day field trials , significant planthopper ( mainly BPH ) control ( 54-60% ) was achieved by biweekly sprays of two fungal candidates ( Ma456 and Ma576 ) at 1 . 5 x 10 ( 13 ) conidia ha ( -1 ) and elevated to 80-83% by incorporating 30 . 8 g buprofezin ha ( -1 ) into the fungal sprays . CONCLUSION : The combined application of the fungal and chemical agents is a promising alternative strategy for BPH control .