Flower power: SD producer lice control made from mums
TRENT, S.D. — Lice and flies are the bane of cattle and their caretakers.
So perhaps it's not so strange that Ted Lacey of Trent, S.D., took the step of alerting Agweek when he found a solution — products of "natural pyrethrins," made from chrysanthemums grown in Australia and Africa.
"I don't want to gain anything from it other than letting producers know they have something to solve this problem," Lacey says, on a recent tour at his Trent, S.D., farm.
Lacey and his son, Andy, run a herd of about 100 cows and cell graze all of the cattle. They feed only their own calves. The Laceys have about 300 acres of crops. The rest is in alfalfa, hay and pasture land. The farm in the past was known for growing potatoes on land that has been irrigated since 1948.
Lacey's awakening came in January 2016.
"We treated the cattle with a pour-on (for lice and worms) and six weeks later, mid-February we had a lice outbreak," Lacey says. Ted attended a first-of-its-kind meeting last spring on lice put on by Dells Veterinary Services of nearby Dell Rapids, S.D., and the rest is history.
Dan Dorn, manages the veterinary clinic where his wife, Corale, is the primary veterinarian. Dorn says that over the past several years winters have been warmer or there have been "streaks of warm weather," and traditional lice controls have failed.
"We don't know if it's weather, or (pest) tolerance, resistance or timing application," Dorn says.
For 20 to 30 years, producers have relied on the "ectin" family of herbicides for lice control: Dectomax (doramectrin chemistry); Cydectin (moxidectin chemistry), Ivermectin (Ivermectin or generics) and Eprinex (eprinomectin). All are similar molecules, and the effectiveness has declined.
Mike Catangui, an entomologist, parasitologist and manager for MWI Animal Health Technical Services in Sioux Falls, S.D., was one of the presenters at the meeting. MWI works with MGK, a manufacturer/vendor based in Minneapolis. MGK manufacturers ULD BP-100, a liquid extract of the pyrethrum plant (chrysanthemum). They also make Evergreen Pyrethrum Concentrate, a product usable in the organic market.
Lance Platt, a South Dakota State University graduate, is market manager for MGK, a company that's been family-owned for four generations since 1902 and has made insect control products since just after World War II. MGK today develops and markets branded insect control products based primarily on natural pyrethrum and synthetic pyrethroids.
Old is new
"Insects haven't developed widespread resistance to natural pyrethrins despite being used for centuries," Catangui says. "Many insect species, such as the house fly, can develop resistance against much simpler man-made or laboratory-synthesized insecticides."
Natural pyrethins collectively refer to the six "ester" molecules simultaneously extracted from the chrysanthemum flowers; any one of these esters can kill insects. Pyrethroids are single manmade "copies" of any of the six naturally occurring esters that comprise pyrethrins. One such synthetic "copy" is permethrin, an insecticide widely used in agriculture for over 40 years now. There is little known resistance to natural pyrethrins in the field despite centuries of use. Insects can usually develop resistance to any man-made insecticides within five years, if used continuously every growing season.
Because there can be differences in the compounds based on where the chrysanthemums are grown (much like wine grapes) they include different levels, which helps keep them effective. Dorn says they're coming into more prominence in part because the price has come down from where they were a decade ago.
In March the Laceys started with three-gallon pump-up sprayer to "raindrop" the insecticide onto some cattle. Eventually they installed standard oilers. In one field, they built a structure that the cattle had to go through so they would walk under an oiler when going to get water.
"In two days we had lice control," Lacey says. "It was really quite amazing. They're all back laying down instead of trying to rub all of the fences down. The lice have really no means of escaping the poison," Lacey enthuses.
Pour-ons tend to get some of the internal parasites while they only work for the lice and flies. "It works all summer long," Ted says. "I used 3 gallons of the product mixed with 15 gallons of mineral oil. We had just wonderful results. I'm so amazed at what it did — got rid of the pinkeye, got rid of the flies. The small calves, they don't have to walk underneath this but if they stand next to mom, the flies fly off them onto mom and the flies are dead."