|Monarchs arrived in three new states this week: Kansas, Tennessee, and North Carolina. Yet, despite strong south winds and warm temperatures late last week, the leading edge of the migration didn't advance appreciably beyond latitude 37°N. Next, the migration stopped in its tracks when the cold snap hit on Monday. Temperatures dropped to freezing even into Texas.
"Winter won't let go! Native Showy milkweed just starting to come up in my garden. A low of 30°F was predicted for Tuesday morning."
April 11, 2014 Kingfisher, Oklahoma
Risk of Frost
Frost damage to milkweed is a hazard monarchs face in the spring, according to Dr. Lincoln Brower. When monarch eggs hatch on damaged plants, the larvae will die of starvation.
Milkweed and Wing Development
A recent study by Dr. Andrew Davis shows how important milkweed is to healthy development of the adult monarch. What happens if milkweed is restricted from late-stage larvae? He tested the effects of food deprivation in the larval stage on multiple measures of adult wing morphology and coloration of monarchs, a species in which long-distance migration makes flight efficiency critical.
Scientists, educators, farmers, and other concerned citizens wrote a letter to President Obama this week urging the United States to restore the landscape with milkweed and nectar plants.