[note: moral anti-realist here. "what matters" can legitimately differ among evaluators, although there are some very common datapoints on each side of the line.]
I think there's a much simpler answer here. Ecosystems matter, individual frogs and insects don't. Basically, a one-word answer to your title question, "no".
There remains very difficult questions about what attributes make individuals matter, and where is the line or gradient from rocks or frogs not mattering to your sibling mattering a lot as an individual.
This kind of issue (among many, many others) is why I don't think the kind of utilitarianism that this applies to is viable.
My moral position only necessitates extending consideration to beings who might in principle extend similar consideration to oneself. So one has no moral obligations to all but the smartest animals, but also your moral obligations to other humans scale in a way which I think matches most people's moral intuitions. So one genuinely does have a greater moral obligation to loved ones, and this isn't just some nepotistic personal failing like it is in most formal moral systems. For the same reasons one has little to no moral obligations towards say serial killers or anyone else who actively wants to kill or subjugate you.
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 frogs to the value of insects?
I don't think this would be very radical as an ethical thought experiment for the right reason. In practice, one would (rightfully) be concerned about the downstream effects of killing all frogs. In practice, this seems to be a large consideration, even for more lopsided cases like getting rid of some mosquitos in exchange for ending Malaria (my guess would be that how much I care about another being is a convex function of the number of neurons or something along those lines). Without this consideration, this doesn't "seem" very radical.
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 became president with a little luck and a little trickery. 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 frogs 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.