Michigan State University Extension
Home Maintenance And Repair - 01500541
06/24/03
Fungus Beetles
The name "fungus beetle" may be applied to several
closely-related groups of beetles. The most commonly
encountered "fungus beetles" are the silken fungus
beetles and the minute brown scavenger beetles.
Both the silken fungus beetles and the minute brown
scavenger beetles are small in size (less than 4 mm),
brownish in color (varying from yellowish to almost
black) and with clubbed antennae. Also, their bodies are
frequently covered with dense pubescence and/or dimple-
like punctures.
Fungus beetles have a complete metamorphosis (egg-
larva-pupa-adult) and the developmental period varies
according to the temperature. For example, at 75 degrees
F the life cycle is completed in 25 to 36 days; at 65
degrees F; 54 days; and, at lower temperatures: up to 5
months!
The name fungus beetle is derived from the habits of
these beetles; they are usually associated with fungi
(molds, mildews, etc.). These beetles have been reported
from houses, cellars, barns, warehouses, granaries and
mills. Specifically, they may be associated with decaying
plant material, woodpiles, mammal, ant or termites nests,
fungi and freshly plastered or papered walls.
As far as is known, these beetles, even those
associated with stored products, feed entirely upon the
spores and hyphae of fungi (especially the beetles may
contaminate stored goods with their excreta and cast
skins. Also, they may mechanically transfer fungal
spores; however, considering the ubiquitous nature of
fungal spores, most suitable materials would be colonized
without the assistance of the beetles.
Control of these beetles can be achieved by a
combination of three tactics: regulation of moisture and
humidity level, elimination of host materials (with
fungi) and insecticidal spot treatments.
Excess moisture and humidity is favorable for the
growth of fungi, and the control of moisture is therefore
an important pre-requisite to successful elimination of
these beetles. Adequate heating and ventilation (even a
period of hot, dry weather) can eliminate an infestation.
Because these beetles and their larvae feed
exclusively on fungi (molds, mildews, etc.) they can be
eradicated by eliminating all fungi. The source of the
infestation may be difficult to locate because the fungi
may be located in neglected stored products (grains,
yeast, etc.), wall voids (rodent and insect nests), on
freshly plastered walls and moldy wallpaper paste, on
basement walls, or around moist window cases or plumbing.
Integrated Fungus Beetle Management
Insecticidal products containing pyrethrins may be
used to subdue active adult fungus beetles which
aggregate around windows or lights.
For a complete listing of suggested control option
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
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 or company.
MSU is an affirmative-action, equal-opportunity 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.
This file was generated from data base 02 on 02/04/08.
Data base 02 was last revised on 06/24/03.
For more information about this data base or its contents please contact
strausc@msu.edu .