SYNERGIC EFFECTS OF AGAVE LECHUGUILLA TOR R GUISHE ON INSECTICIDAL ACTIVITY AGAINST BACILLUS-THURINGIENSIS ON SPODOPTERA-FRUGIPERDA SMITH

This work investigates the insecticidal activity against Spodoptera. f rugiperda Smith of an extract from ''guishe'' (subproduct of the proce ssing of Agave lechuguilla) and a mixture of delta-endotoxin and spore s of Bacillus thuringiensis strain GM-10 (MEEBT). The extract by itsel f produced 20% of mortality when 100 mu g/ml were added to the diet. T he LD(50) and LD(90) of MEEBT were 87 and 300 mu g/ml, respectively. W hen 100 mu g/ml of the extract were mixed with different amounts of ME EBT, only 40 and 136 mu g/ml were necessary to get the DL(50) and DL(9 0) respectively. The guishe extract was not toxic to several crops.