why do silkworms lay eggs only in mulberry leaves ? can they lay eggs in any other kinds of leaves?
Mulberry leaves have a special kind of odor to which the silkworms are attracted to. Moreover, Silkworms only feed on the mulberry leaves for their nutritional requirements. Thus, the newly born silkworm will require mulberry leaves to feed on them. Thus, silkworm lay their eggs on the mulberry leaves and not on any other leave in order to provide the diet for the newly born silkworms.
Silkworm lay eggs on Mulberry leaves because they have an attraction to the oderant present in mulberry known as cis-jasmone. This oderant cannot be found in any other leaves so they lay eggs only on mulberry. Mulberry leaves support their normal development. If moths are not able to find the mulberry leaves, then they can go to fig or other similar leaves to which they are weakly attracted and feed there to fulfil their requirement of proteins and carbohydrates. Leaves other than mulberry leaves do not support their proper growth. So, eggs will not be properly developed into a normal adult due to absence of their preferred diet.