Monitoring Results

Why is there a gap?
The monarchs that returned to this area as adults have finished laying their eggs, and have died, or have moved further north.

Why are so many more eggs observed than other stages?
There is very high mortality of eggs and early instar larvae. Most of the eggs that are observed are either eaten by predators or die of other causes.

Why are there more fifth instars observed than some other larval instars?
This seems odd since there should be fewest of this stage. There are two possible reasons for this commonly reported pattern. First, it could be that 5th instars are easier to find than other stages, and therefore observed more often. Alternatively, monarchs are in the 5th instar stage about twice as long as other stages. This makes them more likely to be spotted during the weekly sampling.