As a side note, this might also be interesting, purely from a utilitarian standpoint. If insect suffering matters, that would completely dwarf all human moral weight, since there are 10^18 of them but only 10^9 of us.

However, perhaps we don't care morally about animals which can't pass the mirror test, on the assumption that this means they have no self-image, and therefore no consciousness. They could feel pain and other stimuli, but there would be no internal observer to notice their own suffering.

If that's the case, animal welfare might still dominate over human welfare, but by a smaller margin. Doing what I described in the previous comment would let us estimate the value of future life in general, if we can determine to within an order of magnitude or so how much we value animals with various traits. This is critical for questions like whether terraforming mars is net positive or net negative.