I think the prey may be a Lacewing but delighted with any correction.
The study referred to above can be found here: https://www.researchgate.net/publication/315495434_Dobosz_R_Abraham_L_and_Roberts_H_2017_Interesting_Lacewings_Neuroptera_Berothidae_Nemopteridae_Myrmeleontidae_from_the_United_Arab_Emirates_Acta_Entomologica_Silesiana_25_1-8
The image below is just before the insect disappears down the throat. In a previous image of a Bee Eater I asked if tossing the prey in the air before swallowing was common - another image in this series showed the insect being tossed just before being swallowed.
Read an article today about a very recent study on the discovery of at least 8 new Lacewing types in the UAE; that is why I'm particularly interested in the prey of this bird. If anybody wants other views of the insect then they can be provided.