SWOSU Professor Begins Third Decade as Editor of The Mayfly Newsletter

Dr. Peter Grant 

Dr. Peter Grant, Bernhardt professor of biology at Southwestern Oklahoma State University in Weatherford, has started his third decade as editor of the publication—The Mayfly Newsletter

The publication was started in 1990 to facilitate communication among ephemeropterists, those who study aquatic insects called mayflies. The newsletter is received by 439 individuals in 48 countries.

Mayflies are aquatic insects that can be found in nearly any freshwater habitat—springs, rivers, ponds, lakes and even temporary pools and watering troughs. 

Grant said over 90 species of mayflies have been documented in Oklahoma. Considering the ecological diversity in the state, more species are expected to be found.

Mayflies are the focus of many scientific studies and well over 200 papers are published about them annually.  Every four years, an international conference on mayflies is held for scientists to share their new discoveries about mayflies. The 2012 gathering is scheduled for Japan, and Grant plans to present results of his research on a mayfly found in Deer Creek at this conference.  Two of his former undergraduate students, Michael Walters and Claudia Wright who participated in this research, will be coauthors.

Since mayflies spend most of their life in water as nymphs, they have been used extensively as indicators of water quality. Bodies of water with diverse communities of mayflies tend to be fairly clean, while those with few or no mayflies tend to have experienced some form of pollution.

The nymphs grow in the water until full grown, which can take anywhere from about one week for a desert species to over two years for large species inhabiting northern latitudes.  When fully grown, they crawl out of the water and molt to a subadult stage, the subimago, which has functional wings.  This is known as emergence but is commonly referred to as a hatch by those who are fly fishing enthusiasts.  For some species, these emergences are so large they can show up on Doppler radar.

The subimago typically flies to nearby vegetation and rests about 24 hours before molting to the adult stage, the imago. Mayflies are the only insect that molt after acquiring functional wings. 

Next, males form mating swarms. Females fly into the swarm, are caught by a male and the two leave on a nuptial flight (which recently made Time magazine‘s top 10 list for weird insect mating rituals). Shortly thereafter, the female will lay eggs in the water. This can be a delicate endeavor with the female gently touching the surface of the water with the tip of her abdomen, releasing only a few eggs at a time. On the other hand, for one type of mayfly common in Oklahoma, the female’s abdomen explodes upon contacting the water, releasing all of the eggs at one time. The nymphs hatch from these eggs to complete the life cycle.

Grant said adult mayflies are unusual in a number of respects. Their mouthparts shrivel and the entire digestive system becomes nonfunctional. As a result, the adults only live a few days at most. They cannot fold their wings on their back like most insects, and they represent the oldest lineage of winged insects existing today. Fossils of mayflies have been found that date back to the Permian Period, about 370 million years ago. Several of these Permian mayfly fossils were collected in northern Oklahoma.

Mayflies occupy important links in the aquatic and terrestrial food chains. In the water they eat algae and detritus (aquatic compost), thereby converting this material into mayfly biomass. Other aquatic animals, such as fish and carnivorous aquatic insects, consume the mayflies. Once the mayflies turn into adults and fly away from the water, terrestrial animals such as spiders, birds and bats feed on them. Over 200 species of predators, aquatic and terrestrial, have been observed to feed on mayflies.

For more information about mayflies, simply Google “mayfly” or “Ephemeroptera.”   Grant said websites hosted by universities or government agencies tend to be better online sources of information. The Mayfly Newsletter has recently been added to SWOSU’s Digital Repository (http://site.ebrary.com/lib/swosudr/home.action) and all issues can be read online. Interested individuals can also contact Grant at 580.774.3294 or peter.grant@swosu.edu for further information.