While fruit flies are major pests, they are also highly speciose and often rapidly evolving native insects. These attributes, combined with their often very close evolutionary links with larval host plants, makes tephritids excellent models for studies in a number of fundamental biological areas, including herbivory, co-evolution, and speciation. The best known example of this is the North American apple maggot system, which is the ‘text-book’ example of sympatric speciation. At QUT we have a number of ongoing project areas that investigate aspects of the basic biology of fruit flies. Such research often proceeds slowly as the questions are complex, but over time the ones we are most interested in at QUT have fallen into three main categories.