State University Extension
Home Maintenance And Repair - 01500547
Nuisance Aquatic Insects, Caddisflies, Stoneflies, and Mayflies
The adults of several types of aquatic insects will frequently emerge
in large numbers, causing concern among homeowners. Three types of
aquatic insects frequently encountered around homes are caddisflies
(Trichoptera), stoneflies (Plecoptera) and mayflies (Ephemeroptera).
Caddisflies are distinct from the other two groups by the hair-covered
wings which are held roof-like over the back when at rest. Mayflies
have large forewings, small hindwings that are held together at rest
over the body. There are also 2 (rarely 3) caudal filaments which are
equal to or greater than the length of the body. Stoneflies have a
hindwing which is larger than the forewing, and the wings are held flat
over the back. There are two caudal filaments, but they are generally
shorter (less than half the length of the body). The adults of these
insects are generally short lived, especially in the case of the
mayflies, and they generally do not feed. Even though homes near
aquatic habitats may be covered with resting insects during mass
emergences, expensive chemical controls are seldom necessary.
The insects can be allowed to disperse naturally, or they can be
removed by sweeping or vacuuming. Those insects which get indoors can
be subdued with an aerosol flying insect spray containing pyrethrin,
and then removed. An ordinary aerosol hair spray will also subdue
flying insects by stiffening their wings and allowing their removal.
These aquatic insects are attracted to lights, and when they are active
it may be necessary to reduce outside lighting or switch to yellow
light bulbs. These insects are least responsive to the yellow light.
For a complete listing of suggested control options for all home, yard
and garden insect pests contact your local Extension Service, found
under local government in the phone book.
Read and follow instructions on the pesticide label. Heed all warnings.
Check with your physician if you have any concerns regarding your
personal health risk.
Tom Ellis, M.S., Department of Entomology.
to main page
This information is for
educational purposes only. References to commercial products or trade
names does not imply endorsement by MSU Extension or bias against those
not mentioned. This information becomes public property upon
publication and may be printed verbatim with credit to MSU Extension.
Reprinting cannot be used to endorse or advertise a commercial product
MSU is an
employer. Michigan State University Extension programs and materials
are open to all without regard to race, color, national origin, gender,
gender identity, religion, age, height, weight, disability, political
beliefs, sexual orientation, marital status, family status or veteran
status. Issued in furtherance of MSU Extension work, acts of May 8 and
June 30, 1914, in cooperation with the U.S. Department of Agriculture.
Thomas G. Coon, Director, MSU Extension, East Lansing,MI 48824. This
information is for educational purposes only. Reference to commercial
products or trade names does not imply endorsement by MSU Extension or
bias against those not mentioned.
information.was reviewed as
of June 2008. For more information about the contents please
for webpage problems