Monarch butterfly on Swamp milkweed wildflower. (Credit: © Mark Herreid / Fotolia) Enlarge

Mar. 13, 2013 — Bad news again for the Monarch butterfly: Drought conditions and historic wildfires the past few years continue to decrease their numbers as they wing across Texas this spring. Worse news: milkweed plants — the only kind they need to survive — are also not in plentiful supply, says a Texas A&M University Monarch watcher.

Craig Wilson, a senior research associate in the Center for Mathematics and Science Education and a longtime butterfly enthusiast, says reports coming from Mexico where the Monarchs have their breeding grounds show their numbers are significantly down, a disturbing trend during much of the past decade.

"The severe drought in Texas and much of the Southwest continues to wreak havoc with the number of Monarchs," Wilson explains.

"The conditions have been dry both here and in Mexico in recent years. It takes four generations of the insects to make it all of the way up to Canada, and because of lack of milkweed along the way, a lot of them just don't make it."

The dry conditions and changing farming practices are hampering the growth of milkweed, the only type of plant the Monarch will digest as it makes its trip north. Texas has had dozens of wildfires in the past few years that have hampered milkweed growth, and even though there are more than 30 types of milkweed (Asclepiadaceae) in the state, the numbers are not there to sustain the Monarchs as they start their 2,000-mile migration trip to Canada. Increased use of pesticides is also adversely affecting milkweed production, he notes.

More of the story, click image