The Biofuels Digest Index™ (BDI), a basket of public biofuels stocks, tumbled 2.38 percent to 86.83 as equities wilted in light of the US debt crisis. For the day, Archer Daniels Midland (ADM) fell 1.87 percent to $31.01, while Solazyme (SZYM) dropped 3.69 percent to $22.69. Among other equities, Amyris (AMRS) retreated 3.17 percent to $23.84. Overall, declines led advances 6 to 1 for the day.