Ruby harvest
Ruby harvests can be caught at 36 Hunter when you wield a Butterfly net and have an empty Butterfly jar, yielding 312 Hunter experience. For catching Ruby harvests barehanded (but still with an empty jar) you need 80 Hunter, this will grant you 1350 Hunter experience. You can find Ruby harvests west of the Grand Exchange and north of Falador.
You can release caught Ruby harvests to get an empty jar again. Doing this also grants a combat boost to other players in multi-combat areas. Releasing a Ruby harvest will increase Attack level by 15% plus 5.
Ruby harvest is also an ingredient used in order to create a Forge regen pouch. The creation of a Forge regen pouch requires a Summoning level of 76. Players need an empty familiar pouch, 141 Spirit shards, a green charm and Ruby harvest. This action grants 134 Summoning XP.