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ATTRA is the national sustainable agriculture information service operated by the National Center forAppropriate Technology under a grant from the Rural Business-Cooperative Service, U.S. Department

of Agriculture. These organizations do not recommend or endorse products, companies, or individuals.NCAT has offices in Fayetteville, Arkansas (P.O. Box 3657, Fayetteville, AR 72702), Butte, Montana,

and Davis, California.

INTRODUCTION

By Preston Sullivan 

NCAT Agriculture Specialist

July 2002

S TORED GRAIN P EST 

M ANAGEMENT 

Effective control of stored -grain pests w ith minim al pes-

ticide u se requires an IPM app roach combining sanitation,

mon itoring, and other p reventive practices. Sanitation in-

volves cleaning bins, elevators, and other conveyers before

new grain is put in storage—the goal being to eliminate

insect eggs, pupae, and dormant adults that will eat and

grow in the stored gra in. Traps are excellent for mon itor-ing pest levels. Many trap s contain pherom one (sex scent)

lures. At least one comp any su pp lies insect traps for mon i-

toring insects in stored grain  (1).

Proper id entification of pests is essential for effective con-

trol. For assistance with insect iden tification , contact the

Cooperative Extension Service or visit the w ebsites listed a t

reference 2.

“Stored Grain Advisor,” a comp uter p rogram for stored-

wh eat managem ent, is a decision-supp ort software program

used to identify pests, pred ict infestations, and recommend

preven tive or remedial action. The program can be dow n-

loaded from the website of its developer, the Grain Marketing and Production Research Center inManhattan, KS (3).

Amon g the n on-toxic treatments th at can be used on stored grain is diatomaceous earth (DE), a

silica prod uct comp osed of the fossilized cell walls of ancient sea algae. This material is mined ,

groun d into a flour, and u sed as an insecticide against a variety of pests. The sharp ed ges of DE cut

the pest’s cuticle covering, resulting in death by dehyd ration. One stored -grain DE produ ct, Insecto™,

is used to top off a grain bin filled w ith fresh grain. The supp liers recomm end cleaning out th e bin

prior to filling it with new grain, then also du sting some Insecto throu gh the fan system. The top

dressing of Insecto™ prevents new infestations from en tering the grain. Insecto™ is a formu lation

of DE plus a feed ingred ient to attract the insects to their death. I have enclosed information on the

use of Insecto™ for controlling stored-grain pests.

Three more m ethods for controlling stored-prod uct pests are cooling, heating, and using carbon

dioxide a s a fumigant. Because m any of the p ests originated in the trop ics, they are susceptible to

cold temp eratu res. Most require temp eratures above 60°F to reach dam aging popu lation levels;

CURRENT TOPIC

NON-TOXIC TREATMENTS

 Drawing courtesy of Cooperative Ext ension Service

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BIOLOGICAL CONTROL

some need temperatu res above 70°F. Therefore, storing grain in a cool place will slow pest develop-

ment. Very cold tem peratu res can be u sed to kill pests; storage at 0°F for 4 days w ill destroy some

species. Heating is also effective; exposure for 30 minutes at 130°F will kill many sp ecies. Two of 

the enclosures (Fields, 1999; Gannon, 2000) provide more details on using temperature for pest

control.

Carbon d ioxide can be u sed to fum igate over a period of two to five days; it kills the insects by

dehyd ration by causing their breathing app aratus to stay open. See the two enclosed articles “Throw-

ing Out th e Garbage” and “Of Bugs an d Borders.” The use of carbon d ioxide to kill stored-grain

pests can be more effective and more economical than other fumigants.

Research is un derw ay on the u se of botanical prod ucts. To date, cham omile, dill, elder, and

wormwood have all shown promise (4).

Oklahoma State University (5) has published the Proceedings of the 4th National Stored Grain

 Integrated Pest Management Workshop (circular E-946). It can be ord ered d irectly throu gh the ento-

mology dep artm ent for $6.00. Finally, most state and coun ty Extension offices offer pu blications on

stored-grain pest m anagement.

Biological control using na tural enemies is anoth er option. The enclosed ar ticles, “Bring on the

Bugs” and “Replacing Fumigants with Beneficial Insects,” detail the use of beneficials for control-

ling pests of stored p rod ucts. You might wish to contact Biofac Crop Care, Inc. (6) f or specifics on

using beneficials for stored-grain p est control. Biofac sells several species of beneficial insects that

attack the major pest insects in stored grain, including granary weevil, rice weevil, maize weevil,

rusty grain beetle, lesser grain borer, confused flour beetle, sawtooth grain beetle, Angoum ois grain

moth, and Indian meal moth. More information on these pests and the beneficials that control

them can be seen at the Biofac website and in the enclosure from their w ebsite.

The bacterial pesticide  Bacillus thuringiensis (B.t.) can be used during grain storage to kill moth

caterpillars that hatch after the grain is stored.  B.t. is effective only against the larval stage of 

insects in the moth family, such as grain moths and Ind ian meal moths. Eggs, pup ae, and adu ltsare not affected. The produ ct must be ingested by the caterpillar in order to work.  B.t. kills cater-

pillars by dam aging their d igestive tract over a period of two or m ore days. There are several

product formulations of  B.t., including Dipel™ and Javelin™.

In sum mary, there are several viable alternatives to pesticides for m anaging stored -grain p ests.

These include beneficial insects, temperature extremes, carbon dioxide fumigation, and diatoma-

ceous earth. These intervention methods, coup led with sanitation and mon itoring, can compr ise a

successful stored -grain IPM program.

From left to right: Confused Flour Beetle, Angoumois Grain Moth, Granary Weevil, Lesser Grain Borer.Photo courtesy of A gri-Marketing Services

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Anon. 2000. Throwing out the garbage. Fumigants and Pheromones. Spring. p. 1.

Fields, Pau l G. 1999. The control of stored -prod uct insects and m ites with extrem e tempera-

tu res. Fum igants and Pheromones. Fall. p. 8–9.

Gann on, Bobbie. 2000. Heat treatm ent checklist. Fumigants and Pherom ones. Spring. p. 2.

Kinzel, Bru ce. 1991. Replacing fumigants with beneficial insects. Agricultu ral Research. Feb-

ruary. p. 14-16.

Anon . No da te. An Insecticide for Control of Grain Insects. 4 p. Accessed Jun e 2002.

<http:/ / ww w.insecto.com>.

Olkowski, William. 1989. Update: New d evelopm ents in non -toxic pest control for stored food

products. The IPM Practitioner. February p. 1-9.

Pow ell, David . 1992. Of bugs and bord ers. Synergy. Winter. p. 27-30.

Shirley, Chr istopher . 1991. Bring on the bugs. The New Farm . July–August. p. 10-13, 16, 17.

ENCLOSURES

The electronic version of Stored Grain Pest Management is

located at:HTMLhttp://www.attra.ncat.org/attra-pub/storedgrain.html

PDFhttp://www.attra.ncat.org/attra-pub/PDF/storedgrain.pdf

By Preston Sullivan

NCAT Agriculture Specialist

Edited by Richard Earles

Formatted by Ashley Hill

CT 174