How the simple shape and soft body of the larvae might explain the success of endopterygote insects

The body forms of the larvae of most endopterygote insects are remarkably similar. I argue that their typical worm-like shape cuts costs; in particular, this allows the larvae to benefit from cheaper moulting and from less costly provision of fuel and oxygen to their respiring tissues. Furthermore, the shape confers a reduction of larval mortality in moulting. Together, these factors allow endopterygote larvae to grow fast and as this speedy growth reduces the dangers of predation, attack by parasitoids and disease before the larvae can reach adulthood, they increase offspring survival. I argue that this goes a long way to explain the very pronounced success of endopterygote insects.