State University Extension
Home Maintenance And Repair - 01500532
Two species of mealworms, the dark mealworm and the yellow mealworm
occur in Michigan. The dark mealworm occurs throughout the U.S., while
the yellow mealworm is absent from the southern states.
Mealworm adults are robust, slightly flattened, 3/4 - 1" long beetles.
The dark mealworm adult is a dull, black color, while the yellow
mealworm adult is a shiny, polished dark brown or black. Mealworm
larvae are shiny, smooth, hardened "worms." They have three pairs of
segmented thoracic legs, and two short, horn-like appendages on the tip
of the abdomen. Full grown larvae are 1 - 1 1/4" in length. Dark
mealworms are dark brown; yellow mealworms are honey-yellow in color.
Mealworms overwinter as partially grown larvae. The overwintered larvae
complete their development in the spring, pupate, and emerge as adults
during the summer (mid July to early August in Michigan). Adults live
for 2 to 3 months. After mating the females deposit 275 to 500 eggs,
either singly or in small batches. The eggs are deposited in areas
where the larvae will find ample food. The eggs hatch in about two
weeks. The larvae feed and grow over a period of 6 to 9 months (as long
as 20 months in some cases), molting a total of 14 or 15 times. Mature
larvae are active and wander in search of pupation sites. Due to this
habit they may be found in any area of the home. The complete life
cycle, therefore, requires 6 months to 2 years for completion. One
generation per year is normal.
Mealworms are scavengers and are most commonly found in damp, spoiled
grain and grain products. Adults and larvae hide in refuse, sacks,
bins, grain and similar undisturbed situations. Adults and larvae are
also found in cereal products, macaroni, meal, bran, meat scraps,
feathers and dead insects.
Mealworms are popular as fish bait and as food for many types of small
pets. They are easy to raise and there is information available on this
subject. Mealworms also show great potential as a source of protein for
Mealworms are seldom a serious problem in homes. Control should begin
with a search for spoiled and infested grain and grain products.
Remember to check bulk storage items (for example, dog food or bird
seed). Also, it is necessary to locate any accumulations of crumbs and
other food material behind appliances and in upholstered furniture.
Keep in mind that both mature larvae and adults wander and may be found
a considerable distance from the source of the infestation.
Integrated Mealworm Management
Location of the infestation, followed by destruction of any mealworms
found, will generally control an infestation.
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.
Revised by Tom Ellis, M.S., Department of Entomology
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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
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are open to all without regard to race, color, national origin, gender,
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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
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