All I could find is that we know they eat brown marmorated stink bugs[0].
"Joro spiders also appear to be able to capture and feed on at least one insect that other local spiders are not: adult brown marmorated stink bugs, an invasive pest that can infest houses and damage crops."
"Joro spiders also appear to be able to capture and feed on at least one insect that other local spiders are not: adult brown marmorated stink bugs, an invasive pest that can infest houses and damage crops."
[0] https://news.uga.edu/joro-spiders-are-here-to-stay/