if you put a body in a web and the spider hasn't eaten it in five minutes and then you take it out and call it scratch then yes, prekilleds don't work well for some arboreals... but if you keep introducing prekilleds and let the spider get hungry it should work for just about everything. i have had avics, poeci's, heteroscodra, pterinochilus (*kinda arboreal) all take prekilled.
if they don't take to prekilled quickly you might go for the live -> mangled -> prekilled -> dead conversion strategy
oh yeah! i firmly believe that predator bugs have to "learn" what kinds of things are good to eat. some are "curious" and try new things with little to no prompting, where as others will have to be starved for 4 months before they breakdown and try something new. even after you get a picky predator to eat somethign the first time it might have to ~"relearn" that it is good to eat. eventually you should be able to teach just about anything that something is good to eat.