Scientific Frontline (Jan. 20, 2012) | University of Florida researchers have discovered a key amino acid essential for human nutrition is also an effective insecticide against caterpillars that threaten the citrus industry. The Lime Swallowtail, or Citrus Swallowtail, is a well-known agricultural pest from southern Asia discovered in the Caribbean in 2006, and researchers say its potential impact on the U.S. citrus industry is cause for serious concern.