Skip to main content
U.S. flag

An official website of the United States government

Bug flows: Don’t count your midges until they hatch

January 1, 2020

Usually when people hear about a “bug problem” it’s due to an undesirable overabundance of insects (think plague of locusts). In the Colorado River in Grand Canyon, however, we are faced with the opposite predicament: the river is essentially devoid of bugs. Aquatic insects are a fundamental component of a healthy river ecosystem. Most aquatic insects spend their juvenile life stages (egg, larva, pupa) in the river and their winged adult life stage flying along the riparian corridor. Throughout these metamorphoses one thing is for certain: aquatic insects are prey for fish, birds, bats, lizards, and even other invertebrates. In Grand Canyon, food web studies conducted by the US Geological Survey (USGS) have demonstrated that populations of both native and sport fish are food limited (Cross et al. 2013, Kennedy et al. 2013). In other words, fish in Grand Canyon are consistently facing a calorie deficit. Indeed, the US Fish and Wildlife Service has cited the inadequate and unreliable food supply as the single greatest problem facing endangered Humpback Chub populations in the Grand Canyon (USFWS 2019).

Citation Information

Publication Year 2020
Title Bug flows: Don’t count your midges until they hatch
Authors Anya Metcalfe, Jeffrey Muehlbauer, Morgan Ford, Theodore Kennedy
Publication Type Article
Publication Subtype Journal Article
Series Title Boatman’s Quarterly Review
Index ID 70208000
Record Source USGS Publications Warehouse
USGS Organization Southwest Biological Science Center