Answer:
The botanist should make an hypothesis for your observation (the interaction between population of beetle and leaves of trees)
Explanation:
According to the scientific method, the first step is to make observations about some process or system. In the present case, the botanist observes a large population of a particular type of beetle eating the leaves of one tree but not the leaves of a nearby tree.
Once an observation was made, the second step is to write an hypothesis that suggest something about the observation (for example beetles choose that trees that have more palatable leaves, or leaves with particular compounds).
After the ywo mentioned steps, the botanist can plan an experiment, execute it and so on.
