With over eighty-five thousand species worldwide, flies form one of the most diverse orders of insects, Diptera. Although a number of these species are reviled as crop pests and carriers of disease, many are beneficial – from the aquatic midges that serve as an abundant food source for migratory birds to the fly pollinators of apples, peppers, mangoes and cashews.

The Xerces Society advocates for the conservation of rare flies and their habitats, most notably the Delhi Sands flower-loving fly. This species is a giant in the fly world. It is more than an inch long, with beautiful green eyes and a craving for nectar. It also is native to the irreplaceable and rapidly disappearing Delhi Sands ecosystem in southern California. Because of urban development, researchers estimate only about 2-3% of the fly’s sand dune habitat remains. Scientists have called the Delhi Sands flower-loving fly a flagship species for the whole Delhi Sands ecosystem. Protecting the Delhi fly’s habitat will preserve important open space that is habitat to a variety of wildlife. In 1993, this fly became the first fly to be listed as endangered under the U.S. Endangered Species Act.


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Delhi Sands flower-loving fly (Rhaphiomidas terminatus abdominalis) by Guy Bruyea