Currently, it's the time of year spent indoors, reading, writing, thinking and identifying last summer's collections. We entomologists anticipate the first days where we can once again enter the field and observe insects.
From the Victorian days when entomology was a gentleman's hobby, insects continue to garner enthusiasts other than professionals. There are myriad guides on the market for butterflies and dragonflies, for tiger beetles, and even smaller taxa such as ant genera. These are most often the charismatic groups, those which have easy identifications, bright coloring, large body sizes or have been championed by workers who go beyond simply being taxonomists. In North America, there are even regional guides for different states.
In between the general field guides (including those for charismatic species) and the specialist lab manuals (like the Manual of the Neartic Diptera or various revisions of genera and families), there is a void of intermediate literature and field guides. We have multiple field guides to Lepidoptera, but what about parasitoid Hymenoptera? What about Diptera families? Clearly there is a need for such literature, as there is little time in the field to pull out a large hardbound key and microscope. This is especially true when the objects of study are still living, and /killing/ them would end any interesting behaviors you may be observing. A relative identification in the field can help put things in perspective later reading your notes, and that is where field guides serve best. Cries of "it's simply too difficult" are not sufficient when the same have been covered nicely in other regions (see the many British and European field guides).
True flies, for example, have a very nice, yet somewhat outdated, manual to all the North American families and genera, and there are many revisions of individual families and genera, but there is no adequate field guide for North America. The closest thing is the Diptera chapter from Peterson Field Guide to the Insects, which is very out of date and not nearly as user friendly as I would like.
Perhaps the only viable option is to champion the cause and write it.