Question

suggest a reason why locust nymph have to moult​

Answer 1

Answer:

gregaria. ... Since in hemimetabolous insects nymphal molts are caused by ecdysones in the presence of juvenile hormones (JHs; [31]), differences in timing and composition of the hormones are likely to underlie the alternative development trajectories in the desert locust, although it still remains to be ascertained

Answer 2

Answer:

After completing each instar the locust nymph sheds, or moults its skin to continue to grow. On hatching the nymph is wingless but with each successive moult the developing wing buds increase in size and these can be used to determine the growth stages of nymphs.