small larvae of obscure groups are not exactly popular among nature photographers (not surprisingly --which makes pics like this one all the more precious), but among specialists, too (most regrettably) --because of the imagocentric attitude dominating the coleopterist community

There's a class this summer that I'm hoping to get funding for that would teach me to identify most beetle larvae to family, so that would be a plus.

i'm a 100% product of this bias myself, and every larva is a painful reminder of this flawed education/culture; nowadays, DNA techniques provide fantastic tool to associate most every mystery larva with the adult (leaving behind the horrors of rearing), and i'm not even talking species-level: we have all too many genera w/o a single known larva

I didn't take it that way. Just inciting a lively debate. :) And yeah, Monotomidae is a great example. Only a few genera with a described larva, and usually it has been done badly.

here's what i find really commendable: mayfly taxonomists tend to abstain from describing new species unless both larvae and reared adult specimens of both sexes are available. exemplary practice, even if brought to life out of the necessity to sort out the big mess left by early workers who described taxa now from adults only, now from larvae alone (the situation somewhat similar to that in the Mutillidae, where males are all too often are not associated with females and keep existing under different potentially synonymous names)
but of course rearing mayflies is a less torturous undertaking as compared to most beetles

Most of the historic material that is available for us to study is pinned adults, and preserving larvae is still more time intensive if it's done right (dang slide-mounts). Not to mention we haven't even gotten around to describing all the adult material of Coleoptera yet.