The use of saline W, a physiological salt solution for experimentation on insect immunity

In a series of induction experiments using various Ringer solutions attempts were made to determine whether saline W, a physiological salt solution for Lepidoptera, when injected into the larval haemocoel of the greater wax moth could be recognized by the insect as a non-self molecule. Laboratory bioassays indicated the loss of insect body integrity following intracoelomic injection of saline W and three other salines, increased levels of haemolymph lysozyme activity (EC 3. 2. 1. 17), and elevated resistance to the bacterial parasite, Pseudomonas aeruginosa. The inducing effect of saline W was stronger than dipterous Ringer's solution or other physiological salines. The stimulating effects indicate that the moth distinguishes between self and non-self, and this provides a new insight into the induction of the immune response.