Where have all the pollinators gone?
First the bees, then the bats-now the butterflies
"In Carbon County this year we spotted only three wild Monarch butterflies-and zero eggs in the field," said Mari Gruber, director of the Bear Mountain Butterfly Sanctuary. "Their numbers are way down. I think they are in trouble as a species.
"I raised over 1,600 Monarch butterflies at the sanctuary," she continued. "More and healthier Monarchs than I ever raised before." Unfortunately, she fears that her good luck is but a sign of a looming disaster.
Monarchs migrate from northern climes like Pennsylvania and Canada in the summer to Mexico where they spend the winter. "The wild population didn't come this year," she explained. "In the past, when they came, they brought diseases with them, and they contaminated the milkweed fields."
Monarch larvae feed exclusively on the milkweed plant. No milkweed-no Monarchs. But wild Monarchs are carriers of diseases which they leave behind when they land on the milkweed-perhaps, in past years, on the milkweed Gruber harvested for her developing Monarchs.
In those past years, she lost many of her cultured Monarchs when they became sick from infected milkweed-but not this year. No wild Monarchs-no diseases transferred to roadside milkweed, no infections transferred to Gruber's cultured Monarchs.
"That didn't happen this year," Gruber noted. "They didn't get the fall diseases."
This year, there has been a sharp decrease in the Monarch population, with reports of declines ranging from 60 to 80 percent. Although potentially threatening, similar drop-offs have happened following severe weather, such as in 2002 when a central Mexico winter storm wiped out 70 to 80 percent of the wintering Monarchs.
This year's weather was a significant contributor to the Monarchs' mortality, killing perhaps a third of the population.
The year began with a drought, followed by a cold snap, followed by a heat wave. The drought set back the growth of the plants. The cold set back the growth of the Monarchs. The heat favored the growth of parasites.
"The heat encourages parasites to come out of the ground to hatch and breed," Gruber explained. "Last year, I found six parasitic flies that attack butterfly caterpillars. This year I stopped counting at 100."
Over the past years, illegal logging in Mexico has reduced the forested cover around the Monarch sanctuaries, allowing in one instance, a freezing rain to penetrate the Monarch nesting areas.
But, according to Gruber, the most significant threat to Monarch survival is herbicide-resistant genetically modified corn. These Monsanto GMO crops, modified to be Roundup resistant, are sprayed with the herbicide to kill surrounding weeds. Unfortunately, milkweed is a weed that grows well near cornfields. No weeds-no milkweed.
According to studies by the University of Minnesota and Iowa State University, milkweed in the cornbelt is down 58 percent and over the same period, Monarch egg production in the region has sunk by 81 percent."
Bees, bats and butterflies are important pollinators, and all are in danger. The bees are continuing to die by the millions of Colony Collapse Disorder. Bats by the millions of White Nose Syndrome. The Monarchs of a yet unnamed syndrome.
"We have partnerships with living creatures," Gruber said. "Pollination is a huge natural partnership. We don't always understand it. We often ignore it. We need to wake up."