Biologists estimate the value of services provided by insects

Economic assessment of ecological services reveals reliance on nature’s bounty

Although the economic importance of insects in providing honey and silk is well known, many other valuable services provided by insects are commonly overlooked. In the April 2006 issue of BioScience, the monthly journal of the American Institute of Biological Sciences, John E. Losey of Cornell University and Mace Vaughan of the Xerces Society for Invertebrate Conservation estimate the value (as indicated by documented financial transactions) of some less well-known services provided by insects. Understanding such services is important because evidence points to a steady decline in beneficial insect populations.

The article’s assessment is restricted to just four services–dung burial, control of crop pests, pollination, and wildlife nutrition–because data are not available to allow a more comprehensive assessment. Moreover, Losey and Vaughan excluded the value of services provided by domesticated insects, mass-reared biological control agents, and commercially raised insects. The authors estimate the annual value of the ecological services that they considered to be at least $57 billion in the United States.

Dung beetles, for example, reduce the effects of parasites and pests on cattle, enhance the palatability of forage to cattle, and make nitrogen in dung more readily available to plants. The authors estimate the value of natural control of crop pests attributable to insects at $4.5 billion annually. Native pollinators–almost exclusively bees–seem to be responsible for over $3 billion-worth of fruits and vegetables in the United States. And insects provide a critical nutritional resource that supports hunting, fishing, and observation of wildlife valued at $50 billion.

Losey and Vaughan stress that their assessment is conservative in that it includes only a fraction of the value of all the services insects provide. They suggest that their estimate implies that an annual investment of tens of billions of dollars would be justified to maintain service-providing insects, and urge that conservation funding pay specific attention to insects and the role they play in ecosystems.