An Introduction to An Introduction to Pantry Pests Pantry Pests

Thomas J. WeisslingThomas J. Weissling

Assistant Professor of EntomologyAssistant Professor of Entomology

University of FloridaUniversity of Florida

Fort Lauderdale ResearchFort Lauderdale Research

Pests of Stored Foods and Products

Infestations of stored product pests are usually caused bybringing infested food home.

Although adults are often found, larvae cause most damageto the commodity.

Stored product pests are either beetles or moths, occasionally mites.

In the home environment pests are, are generally considered an aesthetic problem but can cause allergic reactions in some people when insect parts are ingested.

Many pests are tropical or subtropical in origin…like warmth and humidity but many are adapted to living on foods with low moisture content.

Grouped by feeding habits:

1) Internal FeedersLarvae live entirely within whole grain kernelsRice Weevil, Granary Weevil, Angoumois Grain Moth

2) External FeedersLarvae chew on outside of grainLesser Grain Borer, Drugstore Beetle, Flat Grain Beetle, Cadelle, Khapra Beetle, Cigarette Beetle

3) ScavengersFeed on broken grainConfused Flour Beetle, Red Flour Beetle, Sawtoothed Grain Beetle

4) Secondary PestsFeed on rotting, moldy materialsYellow Mealworm, Psocids, Some Mites

Common insects in Florida associated with whole grain:

Rice weevil (Sitophilus oryzae)

Family Curculionidae

It is 2 to 3 mm long and reddish brown.

The thorax has round pits, and the wing covers have four light spots.

It usually attacks whole corn, has been found in macaroni and spaghetti.

Found in the southern states.

The life cycle can be completed in 30 days.

Rice Weevil, Sitophilus oryzae

Usually found in whole grains, and pastaLife cycle completed in about 30 days

2 - 3 mm long

Clemson Univ.

Rice Weevil

Common insects in Florida associated with whole grain:

Lesser grain borer, Rhyzopertha dominica

Family BostrichidaeIt is 3 mm long and dark brown to black in color. Its head is hidden beneath the thorax. The thorax is very rough, and the overall shape of the beetle is cylindrical. It attacks whole grains, including rice. The eggs are laid in clusters on the surface, and the larvae burrow

into the kernels. The life cycle takes about 58 days.

Lesser Grain Borer

Attacks whole grainLife cycle takes about 58 days

3 mm long

Other Weevils

family BruchidaeThe bean weevil is olive brown, mottled with dark brown and gray, and it is 3 mm long. It has one large and two small spines on the tip of the hind femur, and the legs and antennae are reddish. The cowpea weevil has a large spot in the middle of the wing cover, with black tips on the wings.These weevils attack stored beans and peas. The life cycle can be completed in 21 to 80 days.

Common insects in Florida associated with whole grain:

Weevils (Bruchidae): Cowpea Weevil

Infest whole legumes (beans, peas)

Life cycle completed in 21 - 80 days

3 mm long

Common insects in Florida associated with whole grain:

Augoumois Grain Moth, Sitrotroga cerealella

Family Gelechiidae

Important pests that attacks only whole grains

Will attack grains while still in the field

Adults with 13 – 17 mm wing span

Hind wings buff colored and narrow to a point apically and are

margined with many long hairs

40 – 65 day life cycle

Angoumois Grain Moth

Common insects in Florida associated with broken grain:

Flour beetles, Tribolium spp.

Family TenebrionidaeThe two major species are the red and confused flour beetles.They are both reddish brown and 3 to 4 mm long. Each antenna of the red flour beetle has a three segmented club; The antenna of the confused flour beetle has a four segmented club. Red flour beetles fly; confused flour beetles do not fly. They infest flour and milled grain. The life cycle takes about 30 days.

Flour Beetles, Tribolium spp.

3 - 4 mm long

Infest flour and milled grain

Life cycle takes about 30 days

Confused Flour Beetles

3 – 4 mm long

Feed on broken grains and grain products

Common insects in Florida associated with broken grain:

Mealworms, Tenebrio spp.

Family TenebrionidaeAre the largest insects attacking stored grain and are 13 mm long. The yellow and the dark mealworms are the most common species. Adults are shiny black with well-developed wings. They fly and are attracted to light. Larvae are slender, yellow or dark brown with shiny cuticleThey infest milled grain that has high moisture. The life cycle can be completed in 10 months.Often represent most cases of gastrointestinal canthariasis

Mealworms, Tenebrio spp.

Infest milled grain that has high moisture content

Life cycle takes about 10 months

13 mm long

Common insects in Florida associated with broken grain:

Indianmeal moth, Plodia interpunctella

Family Pyralidae

It has a wingspread of about 19 mm.

The wings are tan on the basal one third and coppery colored

on the rest.

It spins webs on the infested product.

The life cycle can be completed in 60 days.

Indianmeal Moth

Larvae spin webs oninfested products

Infest broken grains, driedmilk, etc.

Life cycle takes 60 days

Wingspan 19 mm

Indianmeal Moth

Common pantry pests in Florida that are general feeders

Sawtoothed grain beetle, Oryzaephilus surinamensis

Family CucujidaeIt is about 2.5 mm long and is brown in color.The body is flattened and the thorax has six sawtoothed projections

on each side. It is common in cereal products and macaroni. Because of its size, it can enter packaging through tiny cracks

and folds. It cannot fly, and its life cycle takes about 30 days.

Sawtoothed Grain Beetle

Cigarette beetle, Lasioderma serricorne.

Family AnobiidaeIt is 3 mm long and reddish brown.The head is bent down under the thorax; the antennae do not

have a club. The wing cover is smooth and covered with golden hairs. Besides attacking tobacco, it infests spices, seeds, and dog food.Can eat pyrethrum powder in doses high enough to kill cockroachesThe life cycle takes 30 to 50 days.

Common pantry pests in Florida that are general feeders

Cigarette Beetle

Common pantry pests in Florida that are general feeders

Drugstore beetle, Stegobium paniceum.

Family Anobiidae It is 2.5 mm long and brown in color. It has a three-segmented club on the antennae. The wing covers have longitudinal lines. It infests flour, cereal, spices, dog food, prescription drugs and

many other products. Can penetrate wood, tin foil, aluminum foil and lead to get to foodIt has a life cycle of about 60 days.

Drugstore beetle

Common pantry pests in Florida that are general feeders

Almond moth, Cadra cautella.

Family PyralidaeIt has a wing spread of about 15 mm. The wings are brownish or blackish gray with the base lighter

than the wing tip, which also has a fringe of hairs. The almond moth infests dried fruit and nuts. The life cycle can be completed in 60 days.

Almond Moth

Infests dried fruit &nuts

Life Cycle completedin about 60 days

Wingspan 15 mm

Common pantry pests in Florida that are general feeders

Dermestid Beetles

Family DermestidaeSize of adults and larvae variableLarvae and adults covered with hairsAre scavengers on a variety of productsCommon species is the Khapra beetleCan cause allergic reactions and gastrointestinal canthariasisLife cycle variable

Dermestid Beetle

Common pantry pests in Florida that are general feeders

Spider Beetles

Family PtinidaeSmall beetles (1.5 – 4.5 mm) with long legs giving a “mite- or

spider-like” appearanceAre usually late succession scavengers

Spider Beetles

Control of Pantry PestsControl of Pantry Pests

A) In Homes

Prevention:

1) Buyer Beware…buy only sealed products

unbroken package not a guarantee of lack of infestation

2) Purchase only the amount of packaged food that can be used in 2 - 4 months

3) Store foods in insect proof containers…prevents entry and escape

4) Store products in freezer

5) Practice cleanliness in storage areas

Control

1) Find source of infestation

2) Remove infested material

Freeze….0oF for 4 days Heat…in oven at 130oF for 30 minutes 3) Clean area where infestation found (vacuum and wash)

Can treat with a residual insecticide

Must insure that insecticide does not come in contact with food,either by removing all food or by covering

After insecticide dries, place paper over treated shelves then replace food

Pheromone sticky traps are also effective. These are available through some home catalogs.

4) Fumigate stored grains (Carbon Dioxide)

Place a chunk of dry ice (0.25 pounds/5 gal. Container) directly on top of grain in storage container. Leave lid loose for 30 min. then seal tightly and do not open for 14 days

SAME PRINCIPLES CAN BE APPLIED TO RESTAURANTS, ETC.

Author: Tom Weissling, University of Florida

Photos: University of Florida Clemson University

Entomology And Nematology Department

Copyright University of Florida 2000

For more detailed information see the Featured Creatures WWW site at

http://creatures.ifas.ufl.edu/