Monarch Butterflies Produce Four Generations A Year To Complete Migration
Monarch butterflies migrate from Nova Scotia to wintering grounds in the woodlands of Mexico each year and it takes 4 generations of butterflies along the way to complete the journey.
The annual migration of monarch butterflies (Danaus plexippus) is one of nature’s most attractive sights, and the monarch is so popular across the United States it is celebrated in a number of celebrations.
Millions of the monarch butterflies make the 3000 mile journey and an interesting thing is the butterflies have to reproduce along the way to complete the whole journey.
The new generation of butterflies have to continue the trip from where the generation before them left off. The last generation lives the longest of the four generations, which allows them to complete the trip.
For the last 15 years fewer and fewer monarch butterflies make the journey because the monarch populations have been decreasing across The United States and Canada.
The reduction in the number of monarch butterflies has been blamed on the loss of milkweed. Milkweed is the natural feeding grounds for the monarch caterpillars and milkweed has been disappearing because of GMO crops.
The use genetically-modified, herbicide-tolerant plants, such as corn as well as soybeans, results in the spreading of pesticides and herbicides that kill the milkweed.
The reduction of the numbers of monarch butterflies has been on the steady decline but the 2013-2014 numbers are very concerning. The average monarch butterfly coverage from 1994-2014 was 6.39 hectares.
This number declined to just 0.67 hectares during the 2013-2014 winter season, which was nearly one-tenth of the 1994-2014 number.
The good thing is a study published in the Conservation Letters revealed most Americans do find value in protecting the monarchs and are willing to spend billions of dollars to protect their habitat by planting milkweed to feed monarch caterpillars.
Seventy percent of those questioned thought conserving monarchs was very important, while only three percent said it was not important.
