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Publication #ENY-225

Booklice and Silverfish1

P. G. Koehler, D. Branscome, and F. M. Oi2

Booklice

Booklice (Figure 1) belong to a group of insects collectively called psocids. The psocids are small, soft-bodied insects, most of which are less than one-eighth of an inch long. They are both winged and wingless. Psocids have chewing mouthparts.

Figure 1. 

Booklouse.

The majority of psocids are outdoor species with well developed wings. They are most commonly found on bark or on the foliage of trees and shrubs. These psocids are frequently called "barklice." Most of the species found in buildings are wingless. Because they are often found among books or papers, they are called booklice. The term "lice" in the names is somewhat misleading because none of these insects are parasites and few of them have a louselike appearance.

Psocids feed on molds, fungi, cereals, pollen, fragments of dead insects, or other similar materials. They cause little loss by actually eating foodstuffs since they do feed chiefly on mold. At times they may become extremely abundant and spread throughout an entire building. In such situations they may contaminate foods and materials to the point the goods must be discarded. Damage to books may be more direct. They eat the starch sizing in the bindings of books and along the edges of pages.

The eggs of psocids are laid singly or in clusters and are often covered with silken webs or debris. Most species pass through six nymphal stages. The entire life span from egg to adult is between thirty and sixty days.

Control

Reduction of moisture to eliminate formation of mold is a very effective method for controlling booklice. Infested furniture, bedding, or other movable furnishings should be thoroughly cleaned and aired. Clean up spilled food products and keep all stored products tightly sealed.

If an insecticide is required, apply a spot treatment or crack and crevice treatment of products found in Table 2, according to label directions.

Precautions

All insecticides are poisons. Read the entire label, including the small print before opening the containers and heed all warnings and cautions. Store pesticides in their original labeled containers out of reach of children, irresponsible people, and pets, and preferably keep under lock and key. Dispose of leftover spray materials and empty containers promptly and safely.

Silverfish and Firebrats

Silverfish (Figure 2) and firebrats may cause damage in the home by eating foods or other materials that are high in protein, sugar, or starch. They eat cereals, moist wheat flour, paper on which there is glue or paste, sizing in paper and bookbindings, starch in clothing, and rayon fabrics.

Figure 2. 

Silverfish.

Silverfish and firebrats are common in homes. The silverfish lives and develops in damp, cool places. Large numbers may be found in new buildings in which the newly plastered walls are still damp. The firebrat lives and develops in hot, dark places, such as around furnaces and fireplaces, and in insulations around hot water or steam pipes.

In apartment buildings the insects follow pipelines to rooms in search of food. They may be found in bookcases, around closet shelves, behind baseboards, windows or door frames.

Silverfish and firebrats are both slender, wingless insects and their bodies are covered with scales. Adults are about one-third to one-half inch long. Silverfish are shiny and silver or pearl-gray in color. Firebrats are mottled gray. The young insects look like adults except they are smaller.

Both insects have two long slender antennae attached to their heads and three long tail-like appendages at the hind end. Each appendage is almost as long as the body.

Silverfish and firebrats are active at night and hide during the day. When objects under which they hide are moved, they dart about seeking a new hiding place.

Biology

Under usual house conditions, silverfish and firebrats develop slowly and have few young. They are hardy and can live for several months without food.

Females lay eggs year round in secluded places, such as behind books or on closet shelves. Eggs are occasionally laid in the open. Silverfish lay only a few eggs at a time but may lay several batches over a period of weeks. The eggs are whitish, oval, and about 1/32 inch long. They hatch in two to eight weeks, the hatching time depending on temperature.

Firebrats lay about 50 eggs one at a time and will lay several batches. The eggs are soft, white and opaque, when laid. They will later have a yellowish tinge. Firebrat eggs hatch in about two weeks. Both insects reach maturity in 3 to 24 months. Their rate of growth depends on temperature and humidity.

Control

The sprays should be applied to floors and wall moldings, behind drawers, under furniture, cracks and crevices, and the floor and ceiling of attics. Outside, treat eaves, mulched flower beds, and storage sheds. Control may not be immediate because hiding insects must come out and contact spray residue. Ten days to two weeks may be required to determine whether or not control has been achieved.

Dusts of the recommended materials may be used for treating walls, voids, crawl spaces, and attics. Space sprays of pyrethrins are useful for controlling exposed insects. See Table 1 and Table 2.

Table 1. 

Insecticides labeled for Homeowner Use.

Formulation

Common Name

Trade Name

Signal Word

Pest

Crack and Crevice

Aerosol

Prallethrin (0.03%), Esfenvalerate (0.05%), MGK-264 synergist (0.3%)

Ortho Roach, Ant & Spider Killer

Warning

silverfish

Aerosol

Pyrethrins, MGK-264, Permethrin

Ortho Ant-B-Gon

Caution

silverfish

Emulsifiable

Concentrate

Beta-Cyfluthrin

Bayer Power Force Carpenter Ant & Termite Killer Plus

Caution

silverfish

Ready-to-Use

Cyfluthrin

Bayer Advanced Home, Home Pest Control Indoor & Outdoor Insect Killer

Caution

silverfish

Indoor Surface Treatment

Aerosol

Prallethrin (0.03%), Esfenvalerate (0.05%), MGK-264 synergist (0.3%)

Ortho Roach, Ant & Spider Killer

Warning

silverfish

Aerosol

Pyrethrins, MGK-264, Permethrin

Ortho Ant-B-Gon

Caution

silverfish

Ready-to-Use

Cyfluthrin

Bayer Advanced Home, Home Pest Control Indoor & Outdoor Insect Killer

Caution

silverfish

Outdoor Barrier

Aerosol

Prallethrin (0.03%), Esfenvalerate (0.05%), MGK-264 synergist (0.3%)

Ortho Roach, Ant & Spider Killer

Warning

silverfish

Emulsifiable

Concentrate

Beta-Cyfluthrin

Bayer Power Force Carpenter Ant & Termite Killer Plus

Caution

silverfish

Emulsifiable

Concentrate

Bifenthrin Ortho Termite & Carpenter Ant Killer Caution silverfish

Emulsifiable

Concentrate

Malathion

Ortho Malathion 50 Plus Insect Spray

Warning silverfish
Granule Carbaryl Ortho Bug-B-Gon Multipurpose Insect Killer Ready-to-Use Granules Caution silverfish

Ready-to-Use

Cyfluthrin

Bayer Advanced Home, Home Pest Control Indoor & Outdoor Insect Killer

Caution

silverfish

Outdoor Broadcast

Emulsifiable

Concentrate

Beta-Cyfluthrin

Bayer Power Force Carpenter Ant & Termite Killer Plus

Caution

silverfish

Emulsifiable

Concentrate

Malathion

Ortho Malathion 50 Plus Insect Spray

Warning silverfish

Ready-to-Use

Cyfluthrin

Bayer Advanced Home, Home Pest Control Indoor & Outdoor Insect Killer

Caution

silverfish

Table 2. 

Insecticides labeled for Commercial Use on booklice (Psocids).

Formulation

Common Name

Trade Name

Signal

Word

Pests

Crack and Crevice

Aerosol Acephate

PT Orthene Crack & Crevice Pressurized Residual

(Whitmire Micro-gen)

Caution

booklice, silverfish

Aerosol Cyfluthrin

PT Cy-Kick Crack & Crevice Pressurized Residual

(Whitmire Micro-gen)

Caution booklice, silverfish
Aerosol Cyfluthrin

PT Cy-Kick CS Pressurized Crack & Crevice Residual

(Whitmire Micro-gen)

Caution

booklice, silverfish

Aerosol Lambda-Cyhalothrin

PT 221L

(Whitmire Micro-gen)

Caution booklice, silverfish

Aerosol

Pyrethrins and Others

PT 565 Plus XLO

(Whitmire Micro-gen)

Caution

booklice, silverfish

Aerosol Pyrethrins and Others

PT Microcare Pressurized Pyrethrum Capsule Suspension

(Whitmire Micro-gen)

Caution

booklice, silverfish

Aerosol

Pyrethrins (0.5%), PBO (4.0%)

PT P. I. Contact Insecticide

(Whitmire Micro-gen)

Caution booklice, silverfish
Bait Hydramethylnon

Eclipse

(Zoecon)

Caution silverfish
Bait Hydramethylnon MaxForce Fine Granule Insect Bait Caution silverfish
Bait Hydramethylnon MaxForce Granular Insect Bait (6 lb) Caution silverfish
Bait Hydramethylnon MaxForce Granular Insect Bait (25 lb) Caution silverfish
Bait Orthoboric Acid Niban FG Caution silverfish
Bait Orthoboric Acid Niban Granular Bait Caution silverfish
Bait Orthoboric Acid

Snuffer

(Nisus)

Caution silverfish
Dust Boric Acid

PT Perma Dust Pressurized Boric Acid Dust

(Whitmire Micro-gen)

Caution booklice, silverfish
Dust Deltamethrin

DeltaDust

(Aventis)

Caution silverfish
Dust Disodium Octaborate Tetrahydrate

NiBor-D

(Nisus)

Caution silverfish
Dust Pyrethrins

PT Tri-Die Silica & Pyrethrum Dust

(Whitmire Micro-gen)

Caution booklice, silverfish
Dust Pyrethrins and Others

PT Tri-Die Pressurized Silica & Pyrethrin Dust

(Whitmire Micro-gen)

Warning booklice, silverfish
Dust Pyrethrins, PBO, Silica Gel

Drione

(Aventis)

Caution silverfish

Emulsifiable Concentrate

Bifenthrin

Talstar F Insecticide/Miticide

(FMC)

Caution

silverfish

Emulsifiable Concentrate

Bifenthrin

Talstar Insecticide/Miticide

(FMC)

Caution

silverfish

Emulsifiable Concentrate

Cyfluthrin

PT Cy-Kick CS Controlled Release Cyfluthrin

(Whitmire Micro-gen)

Caution

booklice, silverfish

Emulsifiable Concentrate

Cypermethrin

Cynoff EC

(FMC)

Caution silverfish

Emulsifiable Concentrate

Cypermethrin

Cynoff Power Spray Insecticide

(FMC)

Warning

silverfish

Emulsifiable Concentrate

Cypermethrin

Cynoff WP

(FMC)

Warning

silverfish

Emulsifiable Concentrate

Cypermethrin

Cynoff WSB

(FMC)

Warning

silverfish

Emulsifiable Concentrate

Cypermethrin

Prevail FT Termiticide

(FMC)

Caution

silverfish

Emulsifiable Concentrate

Permethrin

Dragnet SFR Termiticide/Insecticide

(FMC)

Caution silverfish
Emulsifiable Concentrate Prallethrin

PT ULD SPy-300

(Whitmire Micro-gen)

Caution silverfish
Emulsifiable Concentrate Propetamphos

Catalyst

(Zoecon)

Warning silverfish
Emulsifiable Concentrate Pyrethrins

PT ULD BP-300

(Whitmire Micro-gen)

Caution booklice
Emulsifiable Concentrate Pyrethrins and Others

PT Microcare CS Controlled Release Pyrethrum

(Whitmire Micro-gen)

Caution booklice, silverfish
Emulsifiable Concentrate Pyrethrins and Others

PT ULD BP-100

(Whitmire Micro-gen)

Caution booklice, silverfish
Emulsifiable Concentrate Pyrethrins (0.5%), PBO (5.0%)

PT ULD BP-50

(Whitmire Micro-gen)

Caution silverfish

Emulsifiable Concentrate

Pyrethrins (0.5%), PCO (5.0%)

Pyrenone 50

(Aventis)

Caution silverfish

Emulsifiable Concentrate

Pyrethrins (2.5%), PBO (12.5%)

Synerol Insecticide

(Aventis)

Caution

silverfish
Wettable/ Soluble Powder Cyfluthrin

Tempo 20 WP

(Bayer)

Caution silverfish
Wettable/ Soluble Powder Tralomethrin

Saga WP Insecticide

(Aventis)

Warning silverfish

Indoor Space Treatment

Aerosol Pyrethrins and Others

PT 565 Plus XLO

(Whitmire Micro-gen)

Caution booklice, silverfish
Aerosol Pyrethrins and Others

PT Pro-Control

(Whitmire Micro-gen)

Caution silverfish
Aerosol Pyrethrins and Others

PT Pro-Control Plus

(Whitmire Micro-gen)

Caution silverfish
Aerosol

Pyrethrins (0.5%), PBO (4.0%)

PT P. I. Contact Insecticide

(Whitmire Micro-gen)

Caution booklice, silverfish
Emulsifiable Concentrate Prallethrin

PT ULD SPy-300

(Whitmire Micro-gen)

Caution silverfish
Emulsifiable Concentrate Pyrethrins

PT ULD BP-300

(Whitmire Micro-gen)

Caution booklice
Emulsifiable Concentrate Pyrethrins and Others

PT ULD BP-100

(Whitmire Micro-gen)

Caution booklice, silverfish
Emulsifiable Concentrate Pyrethrins (0.5%), PBO (5.0%)

PT ULD BP-50

(Whitmire Micro-gen)

Caution silverfish
Emulsifiable Concentrate Pyrethrins (0.5%), PCO (5.0%)

Pyrenone 50

(Aventis)

Caution silverfish
Emulsifiable Concentrate Pyrethrins (1.0%), PBO (5.0%)

Pyrenone 100

(Aventis)

Caution silverfish

Emulsifiable Concentrate

Pyrethrins (2.5%), PBO (12.5%)

Synerol Insecticide

(Aventis)

Caution

silverfish

Indoor Surface Treatment

Aerosol

Acephate

PT Orthene Crack & Crevice Pressurized Residual

(Whitmire Micro-gen)

Caution

booklice, silverfish

Aerosol

Cyfluthrin

PT Cy-Kick CS Pressurized Crack & Crevice Residual

(Whitmire Micro-gen)

Caution

silverfish
Aerosol Pyrethrins and Others

PT Microcare Pressurized Pyrethrum Capsule Suspension

(Whitmire Micro-gen)

Caution

booklice, silverfish

Dust Pyrethrins

PT Tri-Die Silica & Pyrethrum Dust

(Whitmire Micro-gen)

Caution booklice, silverfish

Emulsifiable Concentrate

Bifenthrin

Talstar F Insecticide/Miticide

(FMC)

Caution

silverfish

Emulsifiable Concentrate

Bifenthrin

Talstar Insecticide/Miticide

(FMC)

Caution

silverfish

Emulsifiable Concentrate

Cyfluthrin

PT Cy-Kick CS Controlled Release Cyfluthrin Caution

booklice, silverfish

Emulsifiable Concentrate

Cypermethrin

Cynoff EC

(FMC)

Caution

silverfish

Emulsifiable Concentrate

Cypermethrin

Cynoff Power Spray Insecticide

(FMC)

Warning

silverfish

Emulsifiable Concentrate

Cypermethrin

Cynoff WP

(FMC)

Warning

silverfish

Emulsifiable Concentrate

Cypermethrin

Cynoff WSB

(FMC)

Warning

silverfish

Emulsifiable Concentrate

Cypermethrin

Prevail FT Termiticide

(FMC)

Caution

silverfish

Emulsifiable Concentrate Deltamethrin

Suspend SC Insecticide

(Aventis)

Caution silverfish

Emulsifiable Concentrate

Permethrin

Dragnet SFR Termiticide/Insecticide

(FMC)

Caution

silverfish

Emulsifiable Concentrate Pyrethrins and Others

PT Microcare CS Controlled Release Pyrethrum

(Whitmire Micro-gen)

Caution booklice, silverfish
Emulsifiable Concentrate Pyrethrins (0.5%), PCO (5.0%)

Pyrenone 50

(Aventis)

Caution silverfish
Emulsifiable Concentrate Pyrethrins (1.0%), PBO (5.0%)

Pyrenone 100

(Aventis)

Caution silverfish

Emulsifiable Concentrate

Pyrethrins (2.5%), PBO (12.5%)

Synerol Insecticide

(Aventis)

Caution

silverfish
Wettable/ Soluble Powder Cyfluthrin

Tempo 20 WP

(Bayer)

Caution silverfish
Wettable/ Soluble Powder Tralomethrin

Saga WP Insecticide

(Aventis)

Warning silverfish

Outdoor Barrier

Aerosol Acephate

PT Orthene Crack & Crevice Pressurized Residual

(Whitmire Micro-gen)

Caution silverfish

Aerosol

Cyfluthrin

PT Cy-Kick Crack & Crevice Pressurized Residual

(Whitmire Micro-gen)

Caution

booklice, silverfish

Aerosol

Cyfluthrin

PT Cy-Kick CS Pressurized Crack & Crevice Residual

(Whitmire Micro-gen)

Caution

silverfish

Aerosol Lambda-Cyhalothrin

PT 221L

(Whitmire Micro-gen)

Caution booklice, silverfish
Bait Hydramethylnon

Eclipse

(Zoecon)

Caution silverfish
Bait Orthoboric Acid Niban FG Caution silverfish
Bait Orthoboric Acid Niban Granular Bait Caution silverfish
Dust Deltamethrin

DeltaDust

(Aventis)

Caution silverfish
Emulsifiable Concentrate

Bifenthrin

Talstar F Insecticide/Miticide

(FMC)

Caution

silverfish

Emulsifiable Concentrate

Bifenthrin

Talstar Insecticide/Miticide

(FMC)

Caution

silverfish

Emulsifiable Concentrate Cyfluthrin PT Cy-Kick CS Controlled Release Cyfluthrin Caution silverfish
Emulsifiable Concentrate Cyfluthrin

Tempo SC Ultra

(Bayer)

Danger silverfish

Emulsifiable Concentrate

Cypermethrin

Cynoff EC

(FMC)

Caution

silverfish

Emulsifiable Concentrate

Cypermethrin

Cynoff Power Spray Insecticide

(FMC)

Warning

silverfish

Emulsifiable Concentrate

Cypermethrin

Cynoff WP

(FMC)

Warning

silverfish

Emulsifiable Concentrate

Cypermethrin

Cynoff WSB

(FMC)

Warning

silverfish

Emulsifiable Concentrate

Cypermethrin

Prevail FT Termiticide

(FMC)

Caution silverfish
Emulsifiable Concentrate Deltamethrin

Suspend SC Insecticide

(Aventis)

Caution silverfish
Emulsifiable Concentrate Permethrin

Astro Insecticide

(FMC)

Caution silverfish
Emulsifiable Concentrate Permethrin

Dragnet SFR Termiticide/Insecticide

(FMC)

Caution

silverfish

Emulsifiable Concentrate Pyrethrins

Kicker

(Aventis)

Caution silverfish

Emulsifiable Concentrate

Pyrethrins and Others

PT Microcare CS Controlled Release Pyrethrum

(Whitmire Micro-gen)

Caution

booklice, silverfish

Granule Deltamethrin

DeltaGard G

(Aventis)

Caution silverfish
Wettable/ Soluble Powder Cyfluthrin

Tempo 20 WP

(Bayer)

Caution silverfish

Outdoor Broadcast

Bait Hydramethylnon

Eclipse

(Zoecon)

Caution silverfish
Bait Hydramethylnon MaxForce Fine Granule Insect Bait Caution silverfish
Bait Hydramethylnon MaxForce Granular Insect Bait (6 lb) Caution silverfish
Bait Hydramethylnon MaxForce Granular Insect Bait (25 lb) Caution silverfish
Bait Orthoboric Acid Niban Granular Bait Caution silverfish

Emulsifiable Concentrate

Bifenthrin

Talstar F Insecticide/Miticide

(FMC)

Caution silverfish
Emulsifiable Concentrate

Bifenthrin

Talstar Insecticide/Miticide

(FMC)

Caution silverfish
Emulsifiable Concentrate Cyfluthrin

Tempo SC Ultra

(Bayer)

Danger silverfish
Granule Deltamethrin

DeltaGard G

(Aventis)

Caution silverfish
Wettable/ Soluble Powder Cyfluthrin

Tempo 20 WP

(Bayer)

Caution silverfish

Voids/Attics

Aerosol Acephate

PT Orthene Crack & Crevice Pressurized Residual

(Whitmire Micro-gen)

Caution

booklice, silverfish

Aerosol Pyrethrins and Others

PT 565 Plus XLO

(Whitmire Micro-gen)

Caution silverfish
Aerosol

Pyrethrins (0.5%), PBO (4.0%)

PT P. I. Contact Insecticide

(Whitmire Micro-gen)

Caution booklice, silverfish
Bait Hydramethylnon

Eclipse

(Zoecon)

Caution silverfish
Bait Hydramethylnon MaxForce Fine Granule Insect Bait Caution silverfish
Bait Hydramethylnon MaxForce Granular Insect Bait (6 lb) Caution silverfish
Bait Hydramethylnon MaxForce Granular Insect Bait (25 lb) Caution silverfish
Bait Orthoboric Acid Niban FG Caution silverfish
Bait Orthoboric Acid Niban Granular Bait Caution silverfish
Bait Orthoboric Acid

Snuffer

(Nisus)

Caution silverfish
Dust

DeltaDust

(Aventis)

DeltaDust

(Aventis)

Caution silverfish
Dust Disodium Octaborate Tetrahydrate

NiBor-D

(Nisus)

Caution silverfish
Dust Pyrethrins

PT Tri-Die Silica & Pyrethrum Dust

(Whitmire Micro-gen)

Caution booklice, silverfish
Dust Pyrethrins and Others

PT Tri-Die Pressurized Silica & Pyrethrin Dust

(Whitmire Micro-gen)

Warning booklice, silverfish
Dust Pyrethrins, PBO, Silica Gel

Drione

(Aventis)

Caution silverfish

Footnotes

1.

This document is Fact Sheet ENY-225, a series of the Entomology and Nematology Department, Florida Cooperative Extension Service, Institute of Food and Agricultural Sciences, University of Florida. Revised: January 2003.

2.

P. G. Koehler, professor, D. Branscome, graduate assistant, and F. M. Oi, assistant extension scientist, Department of Entomology and Nematology, Institute of Food and Agricultural Sciences, University of Florida, Gainesville.

The use of trade names in this publication is solely for the purpose of providing specific information. UF/IFAS does not guarantee or warranty the products named, and references to them in this publication does not signify our approval to the exclusion of other products of suitable composition. All chemicals should be used in accordance with directions on the manufacturer's label. Use pesticides safely. Read and follow directions on the manufacturer's label.


The Institute of Food and Agricultural Sciences (IFAS) is an Equal Opportunity Institution authorized to provide research, educational information and other services only to individuals and institutions that function with non-discrimination with respect to race, creed, color, religion, age, disability, sex, sexual orientation, marital status, national origin, political opinions or affiliations. For more information on obtaining other extension publications, contact your county Cooperative Extension service.

U.S. Department of Agriculture, Cooperative Extension Service, University of Florida, IFAS, Florida A. & M. University Cooperative Extension Program, and Boards of County Commissioners Cooperating. Millie Ferrer, Interim Dean.


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