Estimated Value of bats to Agriculture in Nebraska Counties (see Boyles et. al. 2011 (2) for details).
Bats have voracious appetites and can eat over their body weight in insects every night. A study in Indiana and Illinois estimated that a colony of 150 big brown bats (Eptesicus fuscus) consumed over 1,200,000 cucumber beetles (Chrusomelidae), June beetles, leafhoppers, and stinkbugs annually(1). Recent research has attempted to quantify the value of pest services from bats. An initial estimate extrapolated the value of a large colony of Mexican free-tailed bats in Texas to the cotton industry and estimated that within the US bats provide $3.7 – 53 billion dollars in agricultural pest control(2). Another study has shown that when bats are excluded from corn fields, corn earworms and fungal infection increase by over 50%. They also observed 20% more yield where bats foraged (3).
Arthropod pests diminish worldwide crop production by 18-26%. Crops losses have nearly doubled despite increased pesticide use (4). Pesticide use has led to resistance in over 400 insect species (1). Additionally, over 50% of modern agricultural pests have become pests due to insecticide use. As increasing amounts or new chemicals are developed undesired human health and environmental consequences are often realized on top of resistant pest populations(4).
All bats in Nebraska eat insects. Around the world over 66% of species are insectivorous. Bats activity is strongly correlated with insect abundance, leading us to believe that bats select foraging areas based on the nightly activity of insects.
Bats eat all types of insects, from small midges and mosquitoes to large beetles and moths. It is estimated that they eat 25% - >100% of their body weight every night.They are known to suppress forest insect populations (2) and likely limit the spread of disease via insects.
In many parts of the world, bats are important pollinators of flowering trees and plants. In North America the Mexican long-nosed bat and lesser long-nosed bat are important pollinators of the Agave cactus, the plant that brings you tequila.
Vampire Bats' saliva was the base for anticoagulants.