Families: Reduviidae, Geocoridae, Anthocoridae, Pentatomidae, Nabidae
Many species of true bugs are predators of insects and mites. Pests susceptible to attack by predatory bugs include flies, aphids, caterpillars, mites, and beetles. Common predatory bugs include assassin bugs, bigeyed bugs, minute pirate bugs, damsel bugs, and predatory stink bugs. They vary in size and color, depending on species. All predatory bugs feed by piercing their prey with narrow mouthparts and sucking out body fluids.
- Predatory bugs are considered natural enemies of arthropod pests and include assassin bugs, bigeyed bugs, damsel bugs, minute pirate bugs, and predatory stink bugs.
- All predatory bugs are in the order Hemiptera and feed by piercing the exoskeleton of their prey and sucking out body fluids. In addition to feeding on insect pests, many predatory bugs are generalist predators that will feed on beneficial insects such as pollinators.
- To maintain healthy populations of predatory bugs, flowering plants should be incorporated in the garden or field and applications of broad-spectrum insecticides should be avoided.
Minute pirate bug. Image credit: John Ruberson, Kansas State University, Bugwood.org.
Common damsel bug. Image credit: Joseph Berger, Bugwood.org
Assassin bug. Image credit: Louis Tedders, USDA Agricultural Research Service, Bugwood.org
Predatory stink bug attacking a pine butterfly. Image credits: Rob Flowers, Oregon Department of Forestry, Bugwood.org
Example of end-to-end mating between two predatory stink bugs, which is a characteristic mating behavior of all true bugs. The female (bottom) is feeding on the larva of a cottonwood leaf beetle. Image credit: Whitney Cranshaw, Colorado State University, Bugwood.org
Eggs of predatory stink bug. Image credits: Whitney Cranshaw, Colorado State University, Bugwood.org
Life history and habits
All predatory bugs have 3 life stages: egg, nymph, and adult. Nymphs often resemble adults but are smaller with incompletely developed wings. Predatory bugs generally produce several generations each year.
Predatory bugs as biocontrol agents
Some predatory bugs can be purchased for release in cases where immediate knockdown of the pest population is desired, or the resident population of predatory bugs is very low or nonexistent. For example, minute pirate bugs are commercially available and will feed on spider mites, aphids, thrips, psyllids, whiteflies, insect eggs, and small caterpillars. In greenhouses and high tunnels, releasing low densities (inoculative augmentation) of minute pirate bugs can be an effective way to establish a reproducing population that will suppress the pest population as it builds. Releasing high densities (inundative augmentation) is another approach that provides immediate pest suppression. One species of assassin bug, Zelus renardii, is also commercially available for control of leafhoppers, aphids, mealybugs, caterpillars, and thrips.
Some predatory bugs, such as damsel bugs, bigeyed bugs, and predatory stink bugs, are not commercially available but are commonly found in gardens and landscapes where they feed on aphids, mites, caterpillars, insect nymphs, larvae, and eggs. Since predatory bugs are generalists, their role in integrated pest management often involves supporting naturally occurring populations that help suppress the pest population. There are several conservation practices that can aid in supporting resident populations of predatory bugs.
Applications of broad-spectrum insecticides should be avoided to help maintain adequate populations of these important natural enemies. Generally, incorporating flowering plants in gardens and crops throughout the growing season will provide suitable habitat and carbohydrate rich food sources for many predatory bugs. Some predatory bugs, such as assassin bugs, benefit from overwintering shelter in the form of perennial and ornamental grasses. Providing adequate water and shelter will also support populations of predatory bugs and increase the diversity of natural enemies to include dragonflies, damselflies, and vertebrate predators such as frogs.
Hodgson, E., and R. Patterson. 2007. Beneficial Insects: True Bugs. Available https://extension.usu.edu/pests/research/beneficial-insects-true-bugs
Patterson, R., and R. Ramirez. 2017. Beneficial True Bugs: Minute Pirate Bugs. Utah State University – Extension. Available https://digitalcommons.usu.edu/cgi/viewcontent.cgi?article=2816&context=extension_curall#:~:text=are%20generalist%20predatory%20hemipterans%20(true,damage%20caused%20by%20specific%20pests.
Ramirez, R., and R. Patterson. 2011. Beneficial True Bugs: Damsel Bugs. Utah State University – Extension. Available https://digitalcommons.usu.edu/cgi/viewcontent.cgi?article=1859&context=extension_curall#:~:text=Damsel%20bugs%20can%20be%20found,and%20they%20have%20bulging%20eyes.
Toscano, K. 2017. Conservation Biological Control for the Home Landscape. Oklahoma State University – Extension. Available https://extension.okstate.edu/fact-sheets/conservation-biological-control-for-the-home-landscape.html
UMD. 2023. Predatory Bugs. University of Maryland – Extension. Available https://extension.umd.edu/resource/predatory-bugs