Bombyx mori the molecular identification of the first known pheromone, bombykol, which required extracts from 500,000 individuals, due to the very small quantities of pheromone produced by any individual worm. Currently, research is focusing on genetics of silkworms and the possibility of genetic engineering. Many hundreds of strains are maintained, and over 400 Mendelian mutations have been described. Another source suggests 1,000 inbred domesticated strains are kept worldwide. One useful development for the silk industry is silkworms that can feed on food other than mulberry leaves, including an artificial diet. Research on the genome also raises the possibility of genetically engineering silkworms
Dauer larva as "L1", "L2", "L3" and "L4". After L4, animals moult to the reproductive adult stage. However, when the environment is unfavorable, L1 and L2 animals have the option to divert their development from reproduction to dauer formation. Signals such as temperature, food supply, and levels of a dauer-inducing pheromone, a population density cue, influence this dauer decision. Dauer larvae are thus considered an alternative L3 stage larva, and this stage is sometimes preceded by L2d. L2d animals are considered pre-dauer and are characterised by delayed development and dark intestines produced by storage of fat. L2d larvae can either continue normal