There is increasing evidence that many pollinators are in decline. In some cases, this is due to habitat loss or fragmentation that results in loss of food and/or shelter. Invasive plant species are a huge problem in that they replace native plant species that may be food sources for pollinator larvae, and may be better nectar sources for the pollinators. We really don't know the pollinator losses from pesticides, but pollinators can directly be impacted from instecticides and indirectly from herbicides that may kill plants used as food.The impact of new or emerging diseases is also mostly unknown. There is some recent evidence that imported diseases may be affecting honey bees through Colony Collapse Disorder. Imported parasites have impacted honey bees (both tracheal and Varroa mites are well documented problems with honey bee colonies) and likely have impacted bumble bees.
Why are pollinators important?
More than 150 food crops in the U.S. depend on pollinators. Pollinators are responsible for over 75% of the world’s flowering plants. Flowering plants produce breathable oxygen and purify water.