Sterling Schaaf for 27 years has successfully battled the mosquito, which the World Health Organization says claims a life somewhere in the world every two minutes.
But Schaaf, retiring Friday as manager of the Animas Mosquito Control District, says spraying for mosquitoes on the wing and applying larvacide on standing water where the insect breeds has pretty much controlled the insect in La Plata County.
Schaaf, 70, who was raised in the Animas Valley where his family settled in 1904, recalls the time before mosquito-control measures were adopted.
“They used to eat us alive,” Schaaf said.
“And how!” said Butch Knowlton, director of emergency management for La Plata County, who was born and raised on a ranch in the north valley.
“We had palomino horses, which after dark would turn black from the number of mosquitoes on their back,” Knowlton said. “If you spread your fingers and patted a horse, you’d leave a bloody handprint.”
The earliest effort to control mosquitoes in the county was by aerial spraying of DDT, banned for use in agriculture in the United States in 1972 and later worldwide.
“In 1960, people realized how bad the situation was,” Schaaf said. “They voted to tax themselves for mosquito control.”
Today, the Animas Mosquito Control District, which Schaaf has led since 1986, covers the city of Durango; the Edgemont Ranch, Falls Creek and Lightner Creek areas; and south along La Posta Road (County Road 213) to the Southern Ute Indian Tribe reservation. The district has a laboratory to identify larva species.
Another part of the county is covered by the Florida Mosquito Control District.
Schaaf, the fourth generation of his family in the valley, tested several fields, some of them overlapping, before he took on the mosquito-control job.
He served four years in the Navy; laid bricks for 21 years; was ordained a minister in the Independent Baptist Church, serving 10 years in four churches in Texas, Colorado and Illinois; and was a chaplain at the La Plata County jail for 13 years.
Schaaf married Virginia Feller, whose parents owned a truck farm along old U.S. Highway 550, now County Road 203. The couple had six sons and three daughters, who have given them 44 grandchildren and four great-grandchildren.
Mosquito control has been his day job, however, for 27 years.
Early on, fogging, as ground spraying of pesticide to kill flying mosquitoes is called, was done with malathion, Schaaf said. When protests about its toxicity mounted, the district switched to permethrin in 1970, Schaaf said.
Fogging is done starting at dusk and then through the night.
“We have few no-sprays (people who refuse to have their property sprayed),” Schaaf said.
In combating mosquito larva, Schaaf said, the district would spray diesel fuel on standing-water sources such as ponds, stream backwaters, dog dishes and street drains to kill larva. Diesel was substituted by mineral oil and, since 2011, by a product called Natular, with dramatic effect, Schaaf said.
The results can be seen in the number of mosquitoes caught during the annual May 1-Sept. 30 trapping season, Schaaf said. In 2011, 27,675 mosquitoes were trapped; in 2012, 8,628 of the insects were trapped; and this year, 1,971 mosquitoes.
“When they’re killed in the water, there are fewer to trap,” he said.
Proactive mosquito control stood La Plata County in good stead when the West Nile virus turned up in the early 2000s, he said.
“We had some West Nile,” Schaaf said. “But it wasn’t a big problem.”
West Nile is one of the mosquito-borne diseases that is common to many places in the world, along with malaria, dengue, rift and yellow fevers, Schaaf said. The mosquito also carries Western equine encephalitis and St. Louis encephalitis that affect horses.
Mosquito species worldwide number more than 3,000, Schaaf said. The United States is home to 164 species, and La Plata County has 23 species, eight of which carry disease.
Schaaf plans to move to lower elevation in Texas because he suffers from pulmonary fibrosis which, he said, is exacerbated by Durango’s 6,512-foot elevation.
Schaaf will be missed, Knowlton said.
“Sterling has stayed abreast of technology and products that are environmentally friendly to do everything possible to control mosquitoes,” Knowlton said. “You can’t measure the value of his skill, dedication and knowledge.”
daler@durangoherald.com
