Looks like there is a new sub-species of Megatibicen pronotalis, to go with Megatibicen pronotalis pronotalis (Davis, 1938) and Megatibicen pronotalis walkeri (Metcalf, 1955) called Megatibicen pronotalis hesperiu. I am going to guess that ‘hesperiu’ refers to the Greek word for evening or western. If it’s western, maybe the hesperiu is an offshoot of M. pronotalis pronotalis.
As on 3/27 I have not read the paper. You can access it here https://mapress.com/zt/article/view/zootaxa.5609.4.2.