420 likes | 1.25k Views
Ephemeroptera: Mayflies. In North America 17 families 680 species (569 in US) PA species. Hemimetabolous. Egg. Larva /nymph/naiad. Adult. Larvae. http://www.cals.ncsu.edu/course/ent425/compendium/mayfly.html. More Larvae. Life History.
E N D
In North America • 17 families • 680 species (569 in US) • PA species
Hemimetabolous Egg Larva/nymph/naiad Adult
Larvae http://www.cals.ncsu.edu/course/ent425/compendium/mayfly.html
Life History • Usually one generation/yr, some have two; others may take 2 years/generation (tend to be larger species) • Eggs always laid in water; hatch in 1 week to several months; diapause may last up to 11 months • Larval stage lasts 3-6 mos (range 10 days-2 yrs); molt many times (more than any other aquatic insect: 12-27 times; 45x in some species); may vary even within species • Emergence: • Float to surface, use exuvium as raft; better be quick! • Crawl to edge (~5cm) to emerge
Life History continued • Have unique subimago life stage: the only flying insect that is not fully developed, i.e., sexually mature • Wings are dull and semitransparent due to fine hairs • Subimagos of same species and habitat usually synchronize emergence…why? • Subimago lasts ~ 24 hrs (range: minutes to 2 days) • Adult is imago-has shiny wings
Reproduction • Adult lives 24 hrs (range: 90 minutes to 2 days); don’t feed-have no mouth parts and degenerate digestive systems • Males-only swarm over water; have distinctive swarming behavior • Lay eggs and die; some explode!
Significance & Ecological Role • Mass emergences may be annoying (Put-in-Bay snowplows; Port Clinton brownout) • Most are sensitive to pollution, hence are clean water indicators • Feed mostly on algae, plant material, detritus • Are the mice and rabbits of the aquatic ecosystem: convert much of the plant matter into animal flesh • An essential link in the food chain