Science & Tech
Scientists hope sugar-loving ladybugs can be enticed to devour agricultural pests
Farmers have been taking a beating in recent years dealing with climate change that freezes citrus, droughts that wither cornstalks, high fuel prices and a dysfunctional Congress that barely got its act together in time to extend the expired Farm Bill, which avoided a sharp increase in the price of milk.
Agricultural pests are another thorn in the side of generational family farmers, who have barely been eking out a living.
Bats, one of nature’s elite consumers of flying pests, have been dying off by the millions from a serious epidemic known as white-nosed fungus with a 90 percent mortality rate. The little winged-creatures that most people try to avoid have an extremely vital economic role in agriculture and timber production.
Ladybugs (male and female) are small, spotted beetles that may not stack up the bat’s ability to consume 1,200 bugs a day, but scientists are hoping a minor change in the diet of some species of ladybugs can induce them to eat a diet lighter on the plant side and heavier on the meat or pest side.
USDA entomologist researchers Jonathan Lundgren and Michael Seagraves were part of a team from the North Central Agricultural Research Lab in Brookings, South Dakota, that studied how a ladybug’s feeding pattern is altered by available food sources. They sprayed sections of soybean fields with a sugar-like nectar and found that ladybugs preferred the sweet-treated foliage over the unsprayed plots of crops.
According to Lundgren and Seagraves, their findings make the case for sugar-feeding as a very important component of using ladybugs for bio-control agents in farm croplands and agro-ecosystems, since the little bugs also like aphids and Colorado potato beetles.
Furthermore, in a follow up study, the researchers concluded that sugar-fed ladybugs increased their survival rate and they were able to produce more eggs than their prey-only counterparts.
Ladybugs, once called lady birds, are prolific around the world, with over 5,000 species, including 450 in North America.
The harlequin ladybug is an example of how the petite beetle can sometimes be less beneficial, because it was brought over from Asia in 1916 to control aphids and has been known to overpopulate in areas where natural enemies are few, including wasps that eat their eggs.
Unlike common perceptions, the spots on a ladybug’s back doesn’t indicate its age, but are used to identify the species along with other characteristics, like overall color.
The use of natural control agents in agriculture can save farmers a lot of money that would otherwise have to be spent on pesticides, with the cost passed on to the consumer.
Plus, the cute little ladybug scamps are much better for the environment.
Jean Williams, environmental and political journalist; PrairieDogPress writer; Artistic Director, Keystone Prairie Dogs.***PrairieDogPress is the media channel for keystone-prairie-dogs.com, which is a fundraising website to support environmental groups for extraordinary efforts to protect Great Plains habitat and prairie dogs in the wild. PDP uses humorous images, social commentary and serious-minded political reports to challenge government on numerous levels, including accountability to the people, the protection of threatened species, the environment and Earth’s natural resources.