Tuesday, September 27, 2011

Caution with Insecticides

Some insects are annoying pest that eat crops, contaminate food, and spread disease. Other insects are considered beneficial. These insects pollinate our crops, producing food and seed. Others help control pest insects. If insecticides are used to kill insect pests, they often kill beneficial insects as well. Insecticides described as “broad spectrum” kill all insects in the area regardless of whether they are considered pest or beneficial. This year’s late-summer spraying of insecticides killed honey bee colonies when other insect pests were the target. Annoying mosquitoes and flies were targeted in urban lawns, but honey bee colonies were killed as well. A Memphis beekeeper found thousands of bees dead on the ground around her hive with dozens of other bees crawling and twitching on the ground. They likely encountered a neighbor’s broad spectrum insecticide spraying arrangement.

An article in The New York Times describes efforts being made to develop methods of delivering poison to mosquitoes. Mosquitoes which spread malaria are a major killer of humans, especially young children, in parts of the world. Diseases, like malaria and dengue, are spread by mosquitoes when they bite humans to suck blood. Female mosquitoes, the only ones that bite humans, need the blood for its iron and protein to lay eggs. The insects can live, however, on nectar from flowers or from ripe or rotting fruit. The Times article,  http://www.nytimes.com/2011/09/27/health/27mosquito.html, describes how researchers are making nectar poisons known as Attractive Toxic Sugar Baits. While the initial trials are proving effective in killing large numbers of mosquitoes, the use of poisoned nectars is particularly troubling to beekeepers. We will be keenly watching the development of poisoned nectars. Many beekeepers feel that the systemic neonicotinoid insecticides now in widespread use affect honey bee immune systems and have a negative effect on honey bee health. Today’s photo shows tree frogs sharing the bee hive; bees seem to completely ignore the vulnerable frogs. Frogs and other amphibians are considered indicators of the health of the environment.

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