Leaf Beetle

ID = Malacorhinus foveipennis (Jacoby, 1879) The remaining 11 species from Mexican list excluded. Type image and original description do not show / describe clearly this pattern in red, but 1) it seems the type had a reduced pattern anyway; 2) colours faded after death. If you look closely, you can see the red suture, humerus, and two discal spots (last missing in type, second pair fused over suture in your example). Type: http://140.247.96.247/mcz/Species_record.php?id=15848 Description: https://www.biodiversitylibrary.org/item/90455#page/596/mode/1up

Feature is characteristic for males of Malacorhinus: http://www.sil.si.edu/DigitalCollections/bca/navigation/bca_12_06_01/bca_12_06_01.cfm?start=609 so probably sexual teasers . . .

I see a salient feature: paired "peaks" on sides of elytra, perfectly symmetrical. May be glandular openings beneath? Ant teasers? Anyway, looks similar to genus Exora.