The Good, the Bad & the Ugly

Good bugs, like lady bugs, are well known to most gardeners as a helper in the garden who eats soft bodied bad bugs like aphids. But there are quite a few good bugs in the garden that are not as familiar to us like assassin bugs, just the name sounds ominous. Many of these natural enemies are not well known to most gardeners, but it is important to know who your "friends" are out there.

Natural Enemies...Who are They?

There are basically 3 groups of natural enemies – parasites, pathogens, and predators. Parasites live and feed in or on a host but doesn't always kill the host. An example of a parasite is the Fly parasite. It is a tiny wasp that parasitizes the pupae of many species of flies. The tiny wasp does not bother humans but watch out if you are a fly. Pathogens are microscopic organisms like bacteria that can infect and kill an insect. A common pathogen is Bacillus thuringiensis or Bt that once ingested will kill bad insects like mosquitos. Predators are insects (varying life stages) that feed on other insects. These are our friends out in the garden like the well known lady bug (or lady beetle) or the green lacewing. But there are many other predators that help us get rid of the bad bugs, so be on the lookout for them; we don't want to squish the wrong bug.

Predator Friends of the Garden - Don't Squish Me!

Predator bugs are out in our yard and garden feeding on the bad bugs but we may not recognize them and know much about them. They are great for the garden but many are not commercially available.
  • Assassin bugs - eat a wide variety of small to medium-sized insect prey including caterpillars, leafhoppers, other bugs, aphid, Glassy-winged sharpshooter, but will also eat lacewings.
  • Bigeyed bugs - mostly found on low-growing row or field crops, their prey includes small caterpillars, flea beetles and mites, insect eggs and other bugs.
  • Mealybug destroyer - both the adults and larvae feed on mealy bugs and some scale.
  • Syrphid flies - adults are good pollinators, feeding on nectar and pollen, but it is the larvae that feeds on aphids and other soft-bodied insects.
  • Soldier Beetle - with over 100 species in California alone, this is a large group of predator bugs. Adults feed on aphids.
  • Minute pirate Bugs - they are generalist predators and appear early in the spring. The adults and the nymphs feed on insect eggs and also on small insects like psyllids, thrips, mites, aphids, whiteflies and small caterpillars.
  • Multicolored Asian Lady Beetle - there are more than 100 variations in spot patterns and color of Asian lady beetles, but the bottom line is that the adults and the larvae are predators of aphids, psyllids and scale.
  • Spider Mite Destroyer Lady Beetle - has the distinctive ladybug shape but has a shiny black surface. The adult and the larvae feed almost entirely on mites.
  • Twicestabbed Lady Beetle - has the common lady beetle half dome shape but is all black with two red dots. The adult and the larvae feed on many species of scale on found on fruit, nut and ornamental trees.
  • Vedalia Beetle - both the adult and larvae feed exclusively on cottony cushion scale in citrus and ornamentals. An introduction of the Vedalia beetle in the 1888 to combat the outbreak of cottony cusion scale in California citrus groves is thought to be the beginning of the use of biological controls in agriculture.
  • Damsel Bug - generalist predators that appear later in the season that prey on thrips, mites, aphids, small caterpillars and leafhoppers. The nymphs look similar to the adults, just smaller and darker color.
  • Spiders - most people cringe when they see a spider, but they are probably more scared of you. This is a HUGE group, but there are some common spiders that are found in the garden that eat a variety of insects and other spiders. Some spiders lay in wait for their prey and some build webs to catch their dinner. Here is a link to some common spiders you might encounter in the garden. Just leave them alone and they will leave you alone.
Lesser Known Beneficial Predators

 

Photo Credits

1. Assassin Bug, Zelus longipes, photo by Gerald J. Lenhard, Louisiana State University, Bugwood.org 2. Bigeyed Bug, Geocoris punctipes, Russ Ottens, University of Georgia, Bugwood.org 3. Mealybug Destroyer, Cryptolaemus montrouzieri, Whitney Cranshaw, Colorado State University, Bugwood.org 4. Syrphid Fly Larva, David Cappaert, Bugwood.org 5. Syrphid Fly Adult, Whitney Cranshaw, Colorado State University, Bugwood.org 6. Soldier Beetle, Peaceful Valley Farm & Garden Supply 7. Colorado Plains Soldier Beetle, Chauliognathus basalis, Whitney Cranshaw, Colorado State University, Bugwood.org 8. Minute Pirate Bug, Orius spp., Whitney Cranshaw, Colorado State University, Bugwood.org 9. Multicolored Asian Lady Beetle-Adult, Harmonia axyridis, Scott Bauer, USDA Agricultural Research Service, Bugwood.org 10. Spider Mite Destroyer, Stethorus punctum picipes, F.C. Schweissing, Bugwood.org 11. Twicestabbed Lady Beetle, Chilocorus stigma, Clemson University - USDA Cooperative Extension Slide Series, Bugwood.org 12. Vedalia Beetle, Rodolia cardinalis, Jeffrey W. Lotz, Florida Department of Agriculture and Consumer Services, Bugwood.org 13. Flower Crab Spider, Misumena vatia, Edward L. Manigault, Clemson University Donated Collection, Bugwood.org 14. Damsel Bug, Nabis spp., Whitney Cranshaw, Colorado State University, Bugwood.org 15. Multicolored Asian Lady Beetle, Harmonia axyridis, Gerald J. Lenhard, Louisiana State University, Bugwood.org

Resources

Biological Control and Natural Enemies of Invertebrates Beneficial Predators

2 comments

  • Patricia, I do not think that ladybugs or lacewings would bother the monarch eggs or caterpillars if there are a bunch of aphids available to eat.

    Suzanne
  • Hi, I raise Monarch caterpillars in mesh cages during the summer months to help increase their population. I have a major problem with tachinid flies that are attacking the monarch caterpillars in my garden. I now have to find the monarch eggs & put them in the cages. Just about any caterpillar that I find on the milkweed in my garden has been parasatized by the fly. I realize the flies are considered beneficial. But is there any way that I can remove them just from my garden so the monarchs there have a chance to become a butterfly? Also I have a problem with aphids on the milkweed. Are there natural remedies for the aphids on the milkweed? I understand that ladybugs & lacewings eat aphids. Will they also eat the monarch eggs & caterpillars? Any advice you can provide will be appreciated.

    Patricia Wyzykowski

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