These are tons of little nat fly things. They are rotting the stamens :( sprayed em but they keep coming back! What's the deal?
The inflorescences of Arum (and many other Aroids besides) release various chemicals that actually attract those flies - they're pollinators. What you're seeing on the spadix/spadices isn't rot, it's the way the plant reproduces! It's completely natural for the top portion of the spadix to fall off after producing pollen, leaving only the berries (the white things visible in the second photo, where you've brushed off some of the flies). Equally the spathe (the one "petal" on the inflorescence) will eventually also fall of; this is also completely normal. The berries will eventually ripen up to red/orange, which is quite decorative. Since the flies are attracted to something the inflorescences produce, spraying won't dent them - they'll just keep coming, because to them the spadix smells like female flies ready to mate. My advice would be not to worry about it at all - it's nature taking its proper course.
