Human-Eating Moth

I'm watching a horror movie.
In one scene there's an elderly woman standing outside her house. She has short, curly gray hair, thick glasses, wearing a purple muumuu dress and sandals.
A moth flies up and lands on her, piercing a bare patch of skin with its long proboscis. It begins to drink.
The woman tries to bat and shoo it off but it stays put. It grows at a rapid rate and in a few seconds it's grown larger than the house. It's now sitting on the roof, still feeding on the woman. She's fallen to the ground and is screaming and writhing until her entire body is sucked into the proboscis. A horrible silence follows.