I am trying to find examples of research on invertebrates, especially drosophila, examining discrimination learning or differential associative learning. Specifically, I am looking for work in in which animals have to learn to form multiple concurrent associations between different cues and different levels of the same reward/punishment. While there are many studies in which subjects must learn that cue A = reward and cue B = punishment/nothing, there seem to be very few in which cue A = high reward and cue B = lower reward.
The only examples I could find were in honeybees (Benard and Giurfa, 2004) and wasps (Tibbetts et al. 2019, looking at transitive inference. Surely I'm missing a lot?
Thanks in advance,
Tomer