So about two days ago, this appeared all of the sudden! I'm wondering if my cactus is getting sunburnt? This one only recieves about 9 or 10 hours of full sun per day, but the temps here have just jumped from highs in the 70's-low-80's to the mid-90's. (Mediterranean climate my ass)
'It' also is effecting one other hylo, but only in about a 0.5cm X 1cm area. Thanks for the assistance!