Photo: Adult stink bug feeding on apple fruit; photo-credit: Hamilton.

Photo: Big brown bats inside bat house; photo-credit: MacKenzie Hall.

Cooperative Extension Fact Sheet FS1270

Ecological and Economic Importance of Bats in Integrated Pest Management

Brooke Maslo, Extension Specialist, Wildlife Ecology
Kathleen Kerwin, Coordinator, Department of Ecology, Evolution, and Natural Resources

Agricultural insect pests cost the U.S. agricultural industry $33 billion per year in crop losses, and destroy approximately 25–50% of crops worldwide. This trend continues despite an increased use of pesticides in recent decades on farms throughout the world. Broad-spectrum pesticides are dangerous to human health, degrade ecosystem function, upset carefully optimized integrated pest management (IPM) programs, and devastate natural insect predators and parasitoids. In addition, the World Resources Institute estimates that up to 400 agricultural pest species may have evolved some degree of pesticide resistance.

One effort to limit pesticide includes the use of biological control agents, which are living organisms that prey upon pest species. While proven effective in some cases, biological control comes with significant economic costs and typically offers only partial control. Biological control agents are typically non-native species and may have long-lasting negative effects on native biodiversity.

Native generalist predators can effectively serve as agents of biological control. Temperate insectivorous bats are highly effective generalist predators, and studies have documented the presence of many agricultural pest species in their diet. Especially during the summer months, when bats are raising young, female bats consume a significant proportion of their body weight in insects per day. Because they feed within a few kilometers of their roost site and return to the same roost every day, bats may play an important role in local suppression of agricultural insect pests.

What Do Bats Eat?

Identifying the insect prey of bats is challenging. Historically, biologists analyzed bat fecal and stomach contents, which involved visually identifying undigested insect fragments. Recently, molecular techniques have allowed identification of insect DNA from bat feces (guano), providing much better information about what a bat eats.

We now know that the majority of a bat's diet consists of moths (lepidopterans), beetles (coleopterans), flies (dipterans), cicadas and leaf hoppers, and true bugs (hemipterans). These orders of arthropods include many important agricultural insect pest species. Some prominent examples include corn earworm moth (Helicoverpa zea), cotton bollworm (Helicoverpa zea), spotted cucumber beetle (Diabrotica undecimpunctata), western corn rootworm (Diabrotica virgifera), and three stinkbug species: green stinkbug (Acrosternum hilare), brown stink bug (Euschistus servus), and brown-marmorated stinkbug (Halyomorpha halys). A detailed list of insect pests in New Jersey known to be consumed by bats is included in Table 1.

Table 1. Insect Pests in New Jersey Known to Be Consumed by Bats
Insect Pest - Latin Name	Insect Pest - Common Name	Bat Species That Consumes Pest	Affected Crops
Abagrotis alternata	mottled gray cutworm	eastern red bat (Lasiurus borealis) northern long-eared bat (Myotis septentrionalis)	potato, tomato, tree fruit, strawberry
Abagrotis ipsilon	black cutworm	eastern red bat	field corn, sweet corn, tobacco, turf grass, wheat
Acleris flavivittana	masked leaf roller moth	big brown bat little brown bat (Myotis lucifugus)	roses, apples, pin cherries
Acleris semipurpurana	oak leaf tier	big brown bat little brown bat	pin cherries
Acrosternum hilare (Chinavia hilaris)	green stink bug	big brown bat (Eptesicus fuscus) eastern red bat hoary bat (Lasiurus cinereus) Indiana bat (Myotis sodalis)	wide variety of vegetable crops, grains, pome fruits, stone fruits
Agnetina capitate	Mediterranean fruit fly	little brown bat	fruit
Agriphila vulgivagellus	vagabond crambus moth	big brown bat little brown bat	corn
Agrotis ipsilon	dark-sword grass moth	big brown bat	vegetables, grains
Ambrosiodmus tachygraphus	bark beetle	big brown bat	peaches, chestnut trees
Ambrosiophilus atratus	ambrosia beetle	big brown bat	hardwood trees
Amphipyra pyramidoides	copper underwing	big brown bat	blueberries
Anagrapha falcifera	celery looper	eastern red bat	celery, lettuce
Apamea amputatrix	yellow-headed cutworm	eastern red bat	grasses, vegetables
Apamea devastator	glassy cutworm	eastern red bat	cereals, corn, grasses
Aptinothrips rufus	thrips	big brown bat	cotton, cereals
Archips cerasivorana	ugly-nest caterpillar moth	eastern red bat	trees (particularly aspen, birch and fruit)
Archips purpurana	omnivorous leafroller	big brown bat little brown bat	apples
Archips semiferanus	oak leafroller moth	eastern red bat big brown bat	oak trees
Astylopsis sexguttata	woodboring beetle	big brown bat	hardwood trees
Automeris io	Io moth	big brown bat	cotton, berries, oak, sassafras, pear, rose
Blastobasis glandulella	acorn moth	big brown bat little brown bat	acorns
Caloptilia coroniella	fall armyworm	little brown bat	birch trees, aspen trees
Chrysoteuchia topiarius	cranberry girdler	eastern red bat	cranberry, cool-season grasses
Clepsis peritana (Ptycholoma peritana)	garden tortrix	northern long-eared bat	strawberry
Conotrachelus anaglypticus	cambium curculio	big brown bat	orchard fruits
Crambus praefectellus	silver-striped webworm	eastern red bat	turf grasses, cereal grains
Culicidae	mosquitoes	Indiana bat	n/a
Curculio proboscideus	primitive weevil	big brown bat	hazelnuts
Cyclocephala borealis	northern masked chafer	big brown bat	turf grasses, corn
Cydia caryana	hickory shuckworm moth	big brown bat	pecans
Cydia latiferreana	filbertworm moth	big brown bat	hazelnut
Cydia pomonella	codling moth	big brown bat	pome fruit, stone fruit, walnuts
Cyrtepistomus castaneus	Asiatic oak weevil	big brown bat eastern red bat Indiana bat	oak trees, chestnut trees
Dermestes lardarius	larder beetle	big brown bat	stored grains
Desmia funeralis	grape leaffolder moth	little brown bat	grapes
Diabrotica undecimpunctata	spotted cucumber beetle	big brown bat Indiana bat little brown bat	cultivated crops, flowers, cucumbers, squash, corn, soybean, cotton, beans
Diabrotica virgifera	western corn rootworm	big brown bat	corn
Dibolia borealis	plantain flea beetle	big brown bat	plantains
Dichomeris ligulella	palmerworm moth	big brown bat little brown bat	apples, cherries
Drosophila spp.	fruit flies	eastern red bat big brown bat little brown bat	fruits, turfgrasses
Drosophila suzukii	fruit fly	big brown bat little brown bat	berries, cherries, grapes, tree fruits
Eucopina tocullionana	white pine cone borer	big brown bat	pine trees, seed orchards
Eumorpha pandorus	pandora sphinx	big brown bat	grapes
Euschistus servus	brown stink bug	big brown bat northern long-eared bat	wide variety of cultivated crops, grains, pome fruits, stone fruits
Euxoa tessellate	tessellate dart moth	eastern red bat	pome and stone fruit, tobacco
Exomala orientalis	Oriental beetle	big brown bat little brown bat	turfgrass, fruits
Frankliniella tritici	eastern flower thrips	big brown bat little brown bat	cotton, vegetables
Grapholita molesta	oriental fruit moth	big brown bat	stone fruit
Gyponana spp.	Homoptera	big brown bat little brown bat	hickory trees, grapes
Halyomorpha halys	brown marmorated stink bug	big brown bat	citrus, pome fruits, field corn, vegetables, soybeans
Harpalus caliginosus	murky ground beetle	big brown bat	strawberries
Harpalus pensylvanicus	PA dingy ground beetle	big brown bat little brown bat	strawberries
Hypena scabra	green cloverworm	eastern red bat big brown bat	corn, legumes
Japanagromyza viridula	oak shothole leafminer	big brown bat	oak trees
Keiferia lycopersicella	tomato pinworm	big brown bat	tomato
Lacanobia subjuncta	speckled cutworm	eastern red bat	berries, cultivated crops, pome fruit, stone fruit
Lygus convexicollis	plant bug	big brown bat	strawberries, alfalfa
Lygus lineolaris	tarnished plant bug	big brown bat little brown bat	cotton
Lymantria dispar	gypsy moth	eastern red bat	hardwood trees, cranberry
Malacosoma americana	eastern tent caterpillar	eastern red bat big brown bat	various hardwood tree species
Malacosoma disstria	forest tent caterpillar	big brown bat little brown bat	orchards
Mayetoila destructor	hessian fly	Indiana bat	wheat
Megacyllene robiniae	locust borer beetle	big brown bat	black locust tree
Melanotus spp.	click beetle	big brown bat little brown bat	turfgrasses, multiple agricultural crops
Metcalfa pruinosa	citrid flatid planthopper	big brown bat little brown bat	orchards, vineyards
Mompha stellella	momphid moth	little brown bat	seed crops
Mythimna unipuncta (Pseudaletia unipuncta)	armyworm moth	eastern red bat big brown bat little brown bat	hay, barley, corn, oats, grass
Myzus persicae	green peach aphid	little brown bat	vegetables
Noctua pronuba	large yellow underwing	eastern red bat	cultivated crops, grasses, ornamental plants
Orgyia leucostigma	white-marked tussock moth	little brown bat	oak trees, maple trees
Oxidus gracilis	greenhouse millipede	big brown bat	potatoes, sugar, beets, carrots, sweet potatoes, strawberries, peas, beans
Pandemis lamprosana	woodgrain leafroller moth	big brown bat	orchards
Parapediasia teterrellus	bluegrass webworm moth	eastern red bat little brown bat big brown bat	turf grasses
Paria fragariae	strawberry rootworm	little brown bat	apple, peach, soybeans, corn, rye, oats, grapes
Patalene olyzonaria	juniper twig geometer	big brown bat	juniper trees, cedar trees
Peridroma saucia	variegated cutworm	eastern red bat	vegetables, legumes, corn, alfalfa
Philaenus spumarius	meadow spittlebug	big brown bat	clover, alfalfa
Phyllophaga anxia	cranberry white grub	big brown bat	softwood trees, hardwood trees
Phyllophaga spp.	scarab/may beetle	big brown bat little brown bat	hardwood trees, soft wood trees, pome fruit, stone fruit, sweet potatoes
Phytocoris conspurcatus	plant bug	big brown bat	fruits
phytocoris eximius	plant bug	big brown bat	pistachios
Phytomyza gymnostoma	leaf miner	big brown bat	leeks, scallions, onions
Platynota flavedana	black-shaded platynota moth	big brown bat	apples
Platynota idaeusalis	tufted apple bud moth	big brown bat little brown bat	pome fruit, stone fruit, various trees
Plodia interpunctella	Indian meal moth	eastern red bat	stored grain
Prionoxystus robiniae	locust borer	big brown bat	hardwood
Proteoteras crescentana	twig borer moth	little brown bat	box elder maple trees
Proteoteras moffatiana	maple shoot borer	big brown bat	maple trees
Proxenus miranda	glistening rustic moth	big brown bat	cantaloupes, sugar beets, strawberries, sweet potatoes
Sitotroga cerealella	angoumois grain moth	big brown bat little brown bat	grains
Sonia constrictana	constricted sonia moth	big brown bat	maple trees
Sparganothis sulfureana	fruitworm moth	big brown bat little brown bat	cranberries
Stegobium paniceum	bread beetle/drugstore beetle	little brown bat	dried tobacco, dried what crops
Stenolophus lineola	seedcorn beetle	big brown bat little brown bat	corn
Stenotus binotatus	plant bug	little brown bat	grasses, wheats
Sunira bicolorago	bicolored sallow	big brown bat	cabbage, tobacco
Taniva albolineana	spruce needleminer moth	little brown bat	spruce trees
Taylorilygus apicalis	broken backed plant bug	big brown bat little brown bat	hardwood trees, coniferous nurseries
Thermobia domestica	firebrat	big brown bat little brown bat	cereal
Tipula spp.	leatherjackets	big brown bat little brown bat	turf grasses
Tolype velleda	velleda lappet moth	big brown bat	apples, plums, ash trees, oak trees
Tylonotus bimaculatus	ash & privet borer	big brown bat	hardwood trees
Udea rubigalis	greenhouse leaftier	eastern red bat big brown bat little brown bat	vegetables, legumes
Xylesthia pruniramiella	Clemens’ bark moth	big brown bat	fruit
Xylobiops basilaris	red-shouldered bostrichid	big brown bat little brown bat	mango
Zale lunata	lunate zale moth	big brown bat	cherries, apples

Economic Importance of Bats

Bats provide an important ecosystem service through pest consumption, which is valued at $22.9 billion annually in the United States. The economic benefits of bats are usually estimated by examining the reduction of pesticide use and avoided costs of crop damage. For example, bats in south-central Texas eliminate the need for at least one application of insecticides on cotton fields, and reduce larval damage to crops, resulting in a net benefit of $741,000 per year. However, bats also contribute more subtle indirect benefits. For instance, bats reduce fungal infections of corn, which in turn, reduces negative impacts on the livestock that consumes it. Pesticide reduction also limits environmental damage and human health risk.

Bat-friendly Agricultural Practices

Modifying habitats to support natural insect predators like bats, termed "conservation biological control," has become a valuable component of integrated pest management (IPM) programs. Big brown bats (Eptesicus fuscus) and little brown bats (Myotis lucifugus) are the two species of bat most commonly found roosting in bat houses and man-made structures in New Jersey. Installing bat houses throughout a farm provides quality bat habitat for these species and can attract large maternity colonies if installed correctly.

Another bat-friendly agricultural practice is to support non-crop habitat such as woodlands, ponds, and meadows on the farm. While big brown and little brown bats do well in man-made structures, other species rely heavily on forested habitat. Maintaining tree lines and forest patches with a diversity of vegetation can help provide habitat for forest-dwelling species. Each bat species consumes a slightly different group of insects; therefore, supporting a diversity of bat species will help increase pest control benefits. In addition, avoiding deconstruction of old structures (i.e., barns) in which bats might be roosting, and keeping standing dead trees in place, can help maintain habitat availability for bats.

Conclusion

Researchers continue to use innovative methods to explore the role of bats as biological control agents. Increasing bat habitat on agricultural lands and in residential areas could promote insect suppression, as well as help to conserve these beneficial animals. For further information, please visit our website at wildlife.rutgers.edu or email us at wildlife@njaes.rutgers.edu.

References

Boyles, J.G., P.M. Cryan, G.F. McCracken, and T.H. Kunz. 2011. Economic importance of bats in agriculture. Science 332: 41-42.
Clare, E.L., E.E. Fraser, H.E. Braid, B. Fenton, and P.D.N. Hebert. 2009. Species on the menu of a generalist predator, the eastern red bat (Lasiurus borealis): using a molecular approach to detect arthropod prey. Molecular Ecology 18: 2532-2542.
Cleveland, C.J., M. Betke, P. Federico, J.D. Frank, T.G. Hallam, J. Horn, J.D. Lopez Jr, G.F. McCracken, R.A. Medellin, A. Moreno-Valdez, C.G. Sansone, J.K. Westbrook, and T.H. Kunz. Economic value of the pest control service provided by Brazilian free-tailed bats in southcentral Texas. Frontiers in Ecology and the Environment 2006 4(5): 238-243.
Dodd, L.E., E.G. Chapman, J.D. Harwood, M.J. Lacki, and L.K. Rieske. 2012 Identification of prey of Myotis septentrionalis using DNA-based techniques. Journal of Mammalogy 93(4):1119-1128.
Kunz, T.H., E.B. De Torrez, D. Bauer, T. Lobova, and T.H. Fleming. 2011. Ecosystem services provided by bats. Annals of the New York Academy of Sciences 1223:1-38.
Maine, J.J., and J.G. Boyles. 2015. Bats initiate vital agroecological interactions in corn. PNAS 112 (40):12438-12443.

December 2020

For more information: njaes.rutgers.edu.

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