In the National News
Neonicotinoid Effects on Slugs
Slugs are among the most challenging pests faced by Mid-Atlantic no-till soybean growers. Scientists report in the Journal of Applied Ecology that the use of neonicotinoids can exacerbate slug problems, thus reducing crop yield. Researchers planted quarter-acre plots with soybean seeds that were either treated with a neonicotinoid or untreated. The team tracked slug and predatory insect populations, and found that the slugs themselves were unaffected by the neonicotinoids, likely because they are mollusks, not insects. However, the slugs did indirectly transmit the insecticide to predatory ground beetles, impairing or killing more than 60 percent of the beetles in the test field. In addition, the neonicotinoids directly decreased activity of other slug predators. The result was a decrease in crop yield by 5% over the untreated field.
Understanding Dragonfly Flight
In an attempt to understand the dragonfly’s ability to maneuver so easily, Cornell University entomologists studied their movement using high speed cameras. A magnet was attached to the underside of dragonflies, allowing them to be suspended upside down from a rod. When the rod was removed, the dragonflies instinctively rolled their body to make a 180-degree turn. By studying this footage, researchers were able to determine that the flight of dragonflies is directly related to the fact that they can rotate their wings, changing the aerodynamic forces acting on each of their four wings. These findings will help to better understand evolution of insects and the wiring of their neural circuitry.
Innovative Treatment For Fire Ants
The red imported fire ant (Solenopsis invicta) damages crops, devastates small animal populations, and inflicts painful stings to livestock and to humans. USDA and collaborative scientists tested many naturally occurring compounds found on the skin of several species of poisonous frogs to determine their effect on fire ants. Past research has already identified about 900 alkaloids found on the skin of poisonous frogs. These frogs actually do not produce the alkaloids; rather, they sequester them by eating other organisms that produce the compounds. The USDA scientists identified one alkaloid found on the skin of Central America’s poisonous frog, Oophaga pumilio (derived from mites) that was able to incapacitate and kill fire ants.
A Surprising Evolutionary Find
Purdue and Colorado State University plant pathologists have discovered that the fungus responsible for walnut thousand canker disease has a rich genetic diversity. They analyzed 209 samples of Geosmithia morbida and found 57 genetic races of the disease. The study showed that thousand cankers disease likely originated in Southern California, rather than Arizona or New Mexico as researchers previously thought. It also showed that it is native to the U.S., as is the walnut twig beetle. They surmise that the fungus and beetle might have caused only minor damage to trees in the West for thousands of years. New mutations led the fungus to suddenly emerge as an important pathogen.
Properties of Ink From a Longhorned Beetle
Governments constantly add new features to paper money to stay ahead of counterfeiters. To simplify the process, researchers turned to Tmesisternus isabellae, a longhorn beetle that can shift from red to gold and back, depending on humidity. The researchers designed an ink, based off the beetle, which changes colors when exposed to ethanol and then returns to its original color. This ink is expected to be long-lasting and difficult to mimic. It has potential to be used in paper currency, color-changing billboards, and art displays.
New Biological Control for lettuce aphid
Danish researchers reported in Environmental Entomology on a potential biocontrol agent for lettuce aphid. They evaluated three commercially available parasitoid wasps and found that Aphelinus abdominalis was effective as a biological control agent. The total mortality inflicted by A. abdominalis within a 24-hour exposure period was 51%. This means that growers may have a new, more effective treatment method than chemical control.
Useful Publications and Apps
• Urban Insect Pests: Sustainable Management Strategies is a new book that discusses control strategies of urban insect pests beyond pesticide products.
• Pesticide and Field Records Plus is an app that helps producers and agriculture businesses record and maintain pesticide application information.
• In Praise of Bees: A Cabinet of Curiosities is a new book that covers all aspects of the relationships between human society and bees.