Ok, so i have awesome success with fruits and veggies for them. In fact, my A.picea colony likes sweet potato to the point were they've relocated half the colony into the chamber theyve eaten out of the potato. As for proteins, i've had trouble getting mine to accept certain foods. I feed mine termites, crickets, and they LOVE fruit flies. They don't touch roaches or meal worms.
Also this species lacks a social stomach, so getting them to accept liquid can be difficult. Aphaenogaster has been observed using makeshift sponges such as moss to absorb liquids and bring it back to the nest. This is also difficult to replicate in captivity considering feeders don't have enough open surface area or output to absorb into a sponge. Trays will have to consist of more then just a drop of liquid as it would likely be covered before consumed. Anything larger and you risk drowning some workers if they get sucked in.You could try soaking something with sugar liquid and offering it on a tray. You could also offer a crystallized form of various nectar and honeys, or just sugar grains.
I've witnessed my species carrying brood to and from the feeder within their nest. The only issue for most is that its IN the nest, and you have to maintain the liquid within the feeder. Not to mention most liquid feeders are unable to fit within a nest, nor are nest accessible to the point of placing a liquid feeder within it and not disturbing the colony.
Loops