Thanks for the question! This is a fully separate and unaffiliated group that only works on scientific research on insect welfare. 

The Insect Institute, to my knowledge, doesn't do any scientific research, nor fund it.

Thanks for the question! This is something I've talked with people a lot about, so have a lot of thoughts on it — apologies for the long response in advance! Answering for myself, and not other people involved:

I’ve never been able to understand how any serious consideration of insect welfare doesn’t immediately lead to the unacceptable conclusion that any cause other than the welfare of demodex mites or nematodes is almost meaningless.

• I broadly don't buy that because conclusions seem strange, we shouldn't engage with them. To me, it's much more unacceptable to think that something could be unacceptable just because we don't like the conclusion. We should pursue truth, and act according to what our best model of the world is.
  • Practical ideas have already emerged from this work, and been implemented. As with many animal welfare issues (e.g. insect welfare, wild animal welfare, etc), what people perceive as absurd isn't due to taking the animals' interest seriously, it's due to utilitarianism being a particularly demanding moral philosophy. The idea of capturing a spider in a cup to take it outside being a good thing to do instead of killing it is a widely held belief.
  • The absurdity you sense all comes from the demandingness of specific ethical systems, so if you're concerned about weird outcomes, I'd probably look there instead. If your moral philosophy is demanding you only care about nematodes and you find that to be a problem, I'd contend that's an issue with your moral philosophy, not an issue with thinking about nematodes.
  • I don't think EA would ever demand working on only one cause, or if it did, that seems like a bad formulation of EA.
• Taking some insects and some other arthropods seriously does not imply taking nemotodes or demodex mites seriously as moral patients (or even consider those as remotely similar animals, though the mites are more complicated). An adult black soldier fly has ~1000x the neurons of a nemotode, and ~1/1000th the neurons of a dog (though neurons shouldn't really be used this way). My understanding is that our last common ancestor with insects is something like 200 million years after our last common ancestor with nemotodes.  
  • I'm pretty sure I've taken this issue as seriously as anyone else in the EA world has for longer than almost anyone else, and I've never believed that anyone should think about nematode welfare ~at all. I think that roughly 0 EA resources should go to nematode welfare. I don't know anyone who thinks that the only causes that matter are nematode welfare or even insect welfare. This is not due to concerns about nematode being rejected out of hand. It's because the evidence for their subjective experience is much weaker.
  • Even if demodex mites can suffer, say, it might be really hard to do anything about that. That doesn't mean we shouldn't do anything about insect farming or other places where we can have impact.
• I think the evidence for insect sentience is incredibly disheartening — I would like to live in a world in which I had a high degree of confidence that insects don't experience suffering. Instead, I live in one where it seems like a reasonable possibility.
  • It is the case that if insects suffer to a reasonable degree, and we take their suffering seriously, it probably implies incredibly significant things about what our relationship to the world ought to be like. I'm unhappy about that, but it seems like something we should face head on, if the evidence suggests it is worth doing.

How do you envision useful, practical ideas emerging from further insect/arthropod welfare work, rather than just a lot of absurd conclusions?

• The insect farming industry takes this issue seriously, so seems perfectly reasonable for people concerned about animal welfare to do so too (e.g. the industry lobbying group in Europe had animal welfare guidelines well before anyone remotely connected to EA had engaged on this issue seriously).
  • Animal welfare based commitments based on insect welfare have been in place at retailers for years (e.g. Asos), and insect welfare is a discussion item at industry conferences, etc.
  • I think likely the single most impactful animal welfare campaign by number of animals impacted was insect-focused: this 2012 Starbucks cochineal campaign.
• I'll also note that this fund exclusively exists to fund scientific research, especially research targeting practical applications. I don't think philosophy, except work like the moral weight project that has direct relevance to developing and evaluating interventions, has much use for animal welfare work at all, and wouldn't personally be in favor of funding it.

Some useful practical ideas that could emerge:

• Inform what welfare requiremens ought to be put into law when farming insects
• Inform and lobby the insect farming industry to protect these welfare requirements (eg corporate campaigns); do this in a similar way to how decapod welfare research has informed the work of the Shrimp Welfare Project
• Understand the impacts of pesticides on insect welfare, and use this to lobby for pesticide substitutes
• Improve the evidence base of insect sentience such that they can be incorporated into law (although I think the evidence is probably at least as strong as decapods which are already seen as sentient under UK Law).

Insect suffering is here now and real, and there is a lot of practical things we could do about it; dismissing it as 'head in the cloud philosophers' seems misguided to me

(Not speaking for this group.)

I’ve never been able to understand how any serious consideration of insect welfare doesn’t immediately lead to the unacceptable conclusion that any cause other than the welfare of demodex mites or nematodes is almost meaningless.

Adding to what others have said already, you could also have moral/normative uncertainty about decision theory and aim to do well across multiple attitudes to risk and uncertainty/ambiguity, and some attitudes will prioritize animals that seem less likely to be conscious more or less than others, some possibly severely discounting invertebrates. You can also be morally uncertain about moral aggregation (by addition in particular, say), and then helping humans might look better on non-aggregative (or only partially aggregative) views.

You can also be morally uncertain about the moral weights of animals in other ways, although I've recently argued against it being very important here, so for me, it's mostly attitudes towards risk and uncertainty/ambiguity and aggregation, and, of course, the particular probabilities and other numbers involved.

I'm personally inclined to focus on arthropods using a decent share of my altruistic budget, but not most of it. I'm fairly concerned about mites, but not specifically demodex mites. I don't care much about nematodes (which are not arthropods, and seem particularly unlikely to matter much to me).