Richard Moore Outdoor Report: Monarch Reign

RIO GRANDE VALLEY, Texas (ValleyCentral) — Those ravenous Monarch caterpillars that were munching their way through South Texas milkweed this past spring completed their miraculous metamorphosis, and their offspring will soon be returning on their multi-generational migration.

Having transformed from egg to chrysalis to emergence, those Rio Grande Valley monarchs headed north to spend the summer.

It took three to four generations of monarchs, as each adult lives just a few weeks reproducing en route, to reach the northern United States and Canada, with each successive generation traveling farther north.

However, as fall migration approaches, the last generation of spring migrants undergoes a startling transformation, as these monarchs will soon embark on a monumental flight of up to 3,000 miles to their wintering grounds in the mountains of central Mexico.

Unlike their predecessors, which migrate through the spring, these fall migrants will not reproduce until they complete overwintering and begin their spring migratory journey.  

This reproductive slowing, known as diapause, allows the monarchs to focus all their energy on the arduous sojourn south.

The fall monarchs, known as the Methuselah generation for their extended lifespan, need lots of nectar to complete their monumental undertaking. 

Eastern monarchs will begin fluttering through the Rio Grande Valley in September and October on their way south, and the Valley is a crucial stopover for refueling.

While adult monarchs feed on a variety of nectar plants, they only lay their eggs on milkweed, and caterpillars only eat milkweed.

Over the past decades, monarch numbers have fluctuated dramatically, but overall plunged drastically by some 90 percent due to habitat loss throughout their range and the use of harmful pesticides. 

Every yard can help make a difference by planting milkweed and avoiding pesticides. If you plant it, they will come.  

It won’t be long before that vanguard of monarchs arrives, and what a joy to see the king of butterflies necataring in your yard and then in spring marveling at that next generation of Monarch caterpillars.