This post was also posted on Less Wrong under the name Carn.
When it comes to this issue, it makes more sense to think of another topic, frogs. Frogs eat insects all the time. This leads to a moral dilemma that will help us answer our question. Do the lives of insects matter more than the hunger of a frog?
Situation 1 ~ No
This is the answer most people would give, so I'm going to look at the implications first. We should allow frogs to continue eating insects, because their existence is more important than the insects'. If you are willing to accept this position, then you necessarily must allow the idea of higher and lower beings into your moral system. There is no way of justifying allowing one kind of being to murder another without saying that some beings get higher priority over others. This kind of reasoning, the kind that most people agree on, leads to other dilemmas. How are higher beings determined? How much more is the frog valued over a fly? Is the annoyance of a human worth more than an insect's life? Insects carry diseases, so should all harmful insects be killed if it saves one human life? However you answer these questions are up to you, but I would say most people would agree that insects barely matter if at all.
This also leads to one of the more controversial questions ~ are all humans equal? With the concept of higher and lower beings, this isn't something you can take for granted. Although no one wants to be in the position to judge a potato farmer, for instance, against Donald Trump, for instance, you now would have to go out of your way to prove that all humans are equal, or at least, they should be treated as if they are equal.
I am actually going to attempt to answer this right now. I would say that all humans should be treated equally because of human potential. Jimmy Carter, for instance, was, not a potato, but a peanut farmer who basically lucked out on his way to becoming the President. I mean, his slogan was "My name is Jimmy Carter, and I'm running for President." How in the world did that convince anybody? Also, Adolf Hitler, for instance, was a homeless painter who ended up getting all of Europe embroiled in a war that cost millions of lives. Since anyone could become anybody given the right circumstances, all humans have this potential in common. This creates a sort of fungibility of humans. Yes, you have to now include some value of the future or of potential in your moral system, but this is the simplest answer for human equality I can think of. For every Jimmy Carter, there were a million equivalent peanut farmers who stayed peanut farmers, and that's perfectly fine. Where do you stand in relation to a peanut farmer? In the exact same place, just as everyone else. This is a very controversial topic, so there isn't much levelheaded discussion about this.
(I don't mean to cast Jimmy Carter as the opposite of a Hitler, but the previous paragraph gives that impression.)
Situation 2 ~ Insects' lives matter more than the hunger of a frog.
This is the harder to defend of the situations, but maybe there are people out there who really think this. In that case, it would make sense to somehow prevent frogs from eating insects. If you were feeling especially radical, you would kill all frogs to save the insects. This, like the other situation, leads to more questions being asked. What is the relationship of the value of flies to the value of insects? Out of all the possible answers to this question, I can only think of one that would generate further discussion ~ the lives of all living things are equal. This sounds like something we are supposed to believe, but if you actually think about it, no one would actually accept the conclusions. Do bacteria count as equal to humans? Viruses don't count as living things, but that always seemed like a technicality to me. If the coronavirus was spread by a bacteria and not a virus, would we be doing a bad thing by stopping it from spreading? If you want to defend this side, by all means, do, but you really are fighting an uphill battle.