Monarch Butterflies may be dying from controversial poisonous insecticides called neonicotinoids, which were created to kill bees.

According to a new study by the University of Minnesota, another published in the daily blog, Beyond Pesticides, an unintended consequence of use of neonicotinoids is the death of the cherished Monarch Butterfly.

The university study shows that the insecticide, which is typically applied to kill weeds, taints nearby milkweed plant, which the Monarch needs to survive.

Entomologist Vera Krischik Ph.D. gave butterflies milkweed plants known to have been treated with a neonicotinoid insecticide in amounts typical to backyard use. They ate the insecticide-laden milkweed for seven days. The two varieties of butterfly, the Painted Lady and the Monarch Butterfly, survived, but their larvae died.

The study results are a concern, as over the last 20 years, the Monarch Butterfly population has declined by 90 percent, according to the daily blog Beyond Pesticides. 

Earlier this week, the Environmental Protection Agency approved "emergency" use in Florida of neonicotinoids on citrus groves.  While the use was permitted in order to kill the pest Asian Citrus Psyllid, which causes "Citrus Greening," studies have shown the pesticide kills honey bees and other important pollinators.  

Florida citrus farmers say the situation with Citrus Greening is urgent and steps need to be taken to protect Florida from losing its entire citrus industry.  Florida claims to have lost almost $1 billion a year in citrus production since 2007, according to the New Times of Broward.

Opponents of the poisonous insecticide say the approval was given without public input on its dangers. Neonicotinoids are banned in Europe.