"[A] lot of insects are parasites or predators that kill other insects. So if we (accidentally, intentionally or indirectly) kill some insects, especially predators, we might save the lives of many other insects. Or stated differently: saving one ladybird might mean killing hundreds of aphids. Second, insects in the wild can have net-negative lives, i.e. short lives with more negative than positive experiences. These are lives not worth living. This is due to their reproductive strategy: a fertile adult insect can lay thousands of eggs. If the insect population does not explode at an extreme exponential rate, it is logically required that almost all of the newborn insects will have to die prematurely. The ways of dying are often extremely negative experiences: coldness, starvation, predation, parasitism,…. If an insect is killed, it prevents the birth of many insects with net-negative lives. So, if most insects face very short lives anyway and die horrible deaths anyway, it is far from clear whether killing insects increases overall future insect suffering. We need much more scientific research to estimate the overall effect of killing insects on global welfare."
January 1, 1970
https://en.wikiquote.org/wiki/Insect_suffering