This attack can be quantiWed using several agent-based
parameters: adult feeding on plant parts, oviposition, eclosion,
larval feeding, pupation; emergence, additional adult
feeding, mating, etc., with each parameter having sublevels
that must be met before the next stage in the phenology of
attack can be achieved. There is also a similar complex
plant phenology that must be matched with the agent phenology
for a signiWcant risk to be presented to the plant
population Louda et al. (1997) has provided a very valuable
start to the analysis of this interaction