Four Generations
Monarchs can produce a new generation in about 30 days, resulting in four generations during the typical breeding season.

The Migratory Generation
This fall, the monarchs that migrate to Mexico will be 4th generation butterflies, the great-great-grandchildren of those that left Mexico last spring.

Regional Differences in Abundance
There are hopeful signs of successful reproduction from the Upper Midwest and across much of Ontario. People are reporting up to a half dozen monarchs at a time, and more eggs and larvae than all of last year.

In contrast, many people in the US Northeast and Canadian Maritimes are still waiting to see their first monarch of the year. The region is farther from Mexico so monarchs arrive later and in lower numbers. A new generation is typically on the wing by mid-July, and monarchs suddenly become detectable then.

In all regions, the population will grow with each generation and monarchs will become increasingly noticeable as the summer wears on.

Fall Migration Begins Mid-August
Monarchs born after mid-August will likely be part of the migratory generation. Get ready to watch for signs that the monarchs are on their way to Mexico again.