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Soybean Aphids Are Headline News in Toronto

August 10, 2001
If misery loves company, then we should be in soybean aphid heaven. Last week, several Canadian newspapers featured the soybean aphids' invasion of Toronto. The airborne pests were so thick they caused home plate umpire Tim Welke to request the roof of the Skydome be closed during the third inning of the Toronto Blue Jays/Baltimore Orioles baseball game. William Babin reported, "They are so thick it almost looks as if the game is being played out during a light snowfall." Most Toronto residents accepted the occurrence as a simple annoyance, but Rosetta Powell, who was quoted in the Toronto Star, had another idea: "I think it's a plague coming down on the city. It's because we're too sinful." Canadian soybean producers in southwestern Ontario may have lost 25% of their crop as a result of the soybean aphid. Eric Richter, Syngenta Seed, London, Ontario, described field conditions for a reporter from The Star: "It's almost like the locust plague in Africa. In some fields, if you tried to put on another aphid it would fall off, there's that many."

For more information on the soybean aphid invasion, visit the following Web sites.

The Star carried three articles:

"Toronto invaded by swarms of aphids"

"Aphids devastate Ontario soybean crops"

"Return of the aphids"

The City Pulse News site features a short video clip of the invasion.

Reports like this help us put our problems in perspective. As Kevin indicated last week, symptoms of injury are beginning to show up in some fields with high densities of soybean aphids and low soil moisture. The number of alate (winged) soybean aphids in the suction traps continued to increase, with counts for the week ending August 3, 2001, as follows:

As we continue to receive reports of greater infestations to the north, data provided by Larry Pedigo and Marlin Rice, Iowa State University, may explain the distribution and infestation levels. Ideal environmental conditions for soybean aphid development are temperatures between 72° and 77°F, with a relative humidity of less than 78%. When temperatures reach 81°F, the aphids' reproductive capacity is reduced by 25%. Perhaps the hot, humid conditions we are experiencing across the state are having an impact on soybean aphid populations.--Sue Ratcliffe

Author: Susan Ratcliffe

The Pest Management and Crop Development Bulletin
Executive Editor: Kevin Steffey, Extension Entomologist

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