The ant made repeated attempts at pulling open the case. It concentrated at the head end but tried different locations on the case. The casemoth did three things in response: (1) nothing, (2) little runs up the twig when the ant was distracted, and (3) bursts of three rapid shakes to try and throw off the ant. There were numerous other Irido ants in the vicinity and the would-be predator interacted with them but they seemed to be more focused on harvesting the leaf hoppers.
Thanks for the fascinating observations. To get a secure identification, you need to take it into captivity, and rear it to get an adult moth. Failing that, we can only conjecture. The long conical shape covered in bands of finely chewed vegetation, has been identified as characteristic of some Lepidoscia species, and a conical case with one or more long sticks attached, like this sighting 4360221, has been noted before at CNM sighting 3388047.