Jumping spiders are usually considered obligate predators where ingestion is preceded by visual or tactile stimuli which elicit hunting behavior. Hungry females of Salticus scenicus were shown to feed upon dead houseflies.
Wolff, Robert J.
"Scavenging by Jumping Spiders (Araneae: Salticidae),"
The Great Lakes Entomologist: Vol. 19
, Article 7.
Available at: http://scholar.valpo.edu/tgle/vol19/iss2/7