I managed to track down the original description of N. nanina and a key against local species of what are now Meleoma (p. 344 below).

• https://lacewing.tamu.edu/neuropterida/neur_bibliography/edoc12/banks1911ref50s-3057.pdf

The entirely pale antennae rule out N. nanina. There's mention of a couple other species with these facial markings from Arizona, all which would be new for the guide. The current combinations are Pseudomallada luctuosus and Meleoma schwarzi.

I've followed that lead to a paper by Adams (pp. 178-180 below) and another by Adams & Garland (esp. pp. 243, 246).

• https://lacewing.tamu.edu/neuropterida/neur_bibliography/edoc12/adams1962ref1289s-6967.pdf
• https://lacewing.tamu.edu/neuropterida/neur_bibliography/edoc12/adams1982ref1310-370.pdf

Adams remarks about M. schwarzi that "it is the only known species, inhabiting semi-desert areas in the southwest, which is green, with two brown dorsal longitudinal stripes and pale antennae," though that seems to either be ignoring P. luctuosus or ruling its region not semi-desert. The stripes down the thorax here are indeed more restricted (comparing descriptions and using N. gravida in an attempt at a proxy for N. nanina), and the markings on top of the head do align well with the photo in the Adams & Garland reference. So this may instead be a lead for P. luctuosus.