Most people are aware that there are 4, sometimes 5 (depending on climate) Monarch generations in a year. The last generation for the United States is the longest living generation, called the Methuselah generation, is the one that will begin the Fall migration to Mexico. Most generations live between 2-6 weeks as a butterfly, with the migrating ones living around 7 months. The question is, what generation are we in now? I wasn't sure if the butterflies that just eclosed (became butterflies) was the migrating one, or will it be their offspring. The question was answered for me the other day, when I saw these 2 in my Sugar Maple creating the next generation! The eggs I will be finding in the next few days will be the generation to fly to Mexico.