Neonicotioids V: Insecticides and Bad Behavior

Honey Bee Hives

Honey Bee Hives

The effects of insecticides on insects have been extensively studied. At high enough doses, insects will die. At lower doses, insects may survive, but present physiological and behavioral changes. Insecticides that target the nervous systems of insects can directly affect the ability of insects to properly orient. In the 1980s, I worked for a company that developed pheromones for insect control. We noted that for some pests, pheromones alone would prevent or suppress mating if the pest population was sufficiently low. At high enough pest density, mating was no longer suppressed. However, by sticking a sublethal dose of a pyrethroid insecticide to a pheromone dispenser, mating could be suppressed at higher population densities. In this case, male moths were visiting pheromone dispensers and contacting a dose of insecticide that did not kill the moths. Instead, the pesticide interfered with the ability of the male moth to follow a pheromone plume and find a mate.

One worry about honeybee exposure to pesticides (including neonicotinoids) is potential sublethal effects. Honeybees are social insects. Foragers collect food and must find their way back to the hive. A dose of pesticide that is too low to kill a foraging bee might still disrupt its ability to find its nest possibly by impairing its vision. Impairing the ability of foragers to return to the hive may place additional stress on the honeybee colony and interfere with pollination. Thus protecting honeybees from lethal doses of a pesticide may not be enough. The threshold for protection may be lower- below the level where behavior is altered. The sublethal effects of neonicotinoids on honeybee behavior is an important area for further research.

About jjneal

Jonathan Neal is an Associate Professor of Entomology at Purdue University and author of the textbook, Living With Insects (2010). This blog is a forum to communicate about the intersection of insects with people and policy. This is a personal blog. The opinions and materials posted here are those of the author and are in no way connected with those of my employer.
This entry was posted in behavior, by jjneal, Environment, Pest Management, Policy. Bookmark the permalink.

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