In a study by researchers at the University of Nevada, Las Vegas, honey bee larvae treated with 5-chloroindole were better able to survive exposure to the bacteria that causes American foulbrood disease. All the larvae shown above have been exposed to Paenibacillus larvae spores, but the larva on the far right has also received treatment with the indole analog, which can prevent spore germination. The two larvae on the left are brownish in color, which is characteristic of American foulbrood disease. The indole-treated larva on the right has a healthy appearance, plump and white. (Photo credit: Israel Alvarado, Ph.D.)