WSU Extension


Predatory Bugs
Ambush bugs 
Assassin bug 
Big-eyed bugs 
Damsel bugs 
Minute pirate bugs 
Stink bugs 

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Caption: Adult ambush bug (Phymata sp.) (Phymatidae)
Photo by: D.G. James
Predatory Bugs : Ambush bugs
(revision date: 10/3/2018)

Ambush bugs are closely related to assassin bugs but are smaller (1/2 inch) and specialize in preying on insects visiting flowers. Hiding within the flowers they kill unsuspecting wasps, flies, bees and butterflies. Immature ambush bugs, however, live on other parts of the plant and contribute better to garden pest control by feeding on small soft bodied insects and mites. Batches of eggs cemented together by hardened froth may be found on twigs or fences in the fall and winter.

Prey or Pest Targeted
  • Mites, aphids, leafhoppers, thrips, caterpillars, mealybugs, beetles, scale insects, insect eggs
Attracting and Keeping Natural Enemies & Pollinators in Your Yard
  • Avoid regular use of synthetic, broad-spectrum pesticides. Infrequent use of certain narrow-spectrum pesticides is more compatible with some beneficials but generally the less chemical inputs there are, the greater and more diverse the beneficial insect community will be. Extensive lawns are also not conducive to attracting and retaining a diversity of beneficial insects, mites and spiders. Minimize lawn areas and maximize shrub and bush plantings. Many beneficials reside naturally in riparian and other ‘natural’ areas near to many back yards. Natural dispersion from these refuges ensures that some beneficials will visit back yards but they will not stay unless food, host and shelter resources are available. Native plants have closer affinities with native insects and therefore provide most of these resources. A garden with a good diversity of local native flora in and around back yards, will improve the abundance and diversity of local, beneficial arthropods. Native flora also provides natural overwintering sites for many beneficial insects and it is useful to leave at least a small area of native vegetation undisturbed during fall and winter.
  • Some kinds of beneficial insects (e.g. lady beetles, lacewings, predatory mites) are available for purchase from commercial suppliers. However, benefits from introducing these beneficials are usually limited and short-lived. Upon release, commercially obtained lady beetles and lacewings often disperse and may rapidly leave your backyard despite the presence of prey and suitable nectar resources. Generally, it is more effective and sustainable to create a garden habitat that will be colonized by beneficials naturally.


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Caption: Adult ambush bug (Phymata sp.) (Phymatidae)
Photo by: D.G. James
Caption: Ambush bug nymph (Phymata sp.) (Phymatidae)
Photo by: D.G. James
Caption: Egg mass of ambush bug (Rhynocoris ventralis) (Reduviidae)
Photo by: D.G. James