Most garden pests have natural predators, but those aggressors don't always come to our gardens when we need them. Sometimes we can tailor our gardens and landscapes to attract the beneficial insects, but not always. That's when mail-order comes into play. A number of companies advertise the sale of beneficial insects and nematodes, as well as organic control methods for invasive weeds or plants. An Internet search on "buy beneficial insects" will bring up a good list of places to research, as does the Garden Watchdog.

The following list covers most of the common pests we see in our landscapes.

Pests & Method of Control
  • Alfalfa weevils: Ladybird beetles (ladybugs), Praying Mantids (Tenodera aridifolia sinensis)
  • Ants: nematodes to kill; diatomaceous earth or spray containing d-Limonene (orange peel oil) to repel; non-toxic traps
  • Aphids: Ladybird beetles (ladybugs), Aphid Parasitic Wasp (Aphidius colemani), Green Lacewing or "aphid lions" (Chrysoperla spp.), Praying Mantids (Tenodera aridifolia sinensis), Whitefly Predator (Delphastus catalinae), Mealybug Destroyer (Cryptolaemus montrouzieri), Beauveria bassiana GHA strain fungus; Neem oil organic insecticide; non-toxic repellent
  • Armyworms: nematodes, moth egg parasites (Trichogramma spp.)
  • Asiatic garden beetles: nematodes
  • Asparagus beetle larvae: Ladybird beetles (ladybugs)
  • Bean thrips: Ladybird beetles (ladybugs) , Praying Mantids (Tenodera aridifolia sinensis)
  • Black flies: bacteria Bti (Bacillus thuringiensis var. israelensis)
  • Black vine weevil: nematodes
  • Bollworms: moth egg parasites (Trichogramma spp.)
  • Borers: nematodes, moth egg parasites (Trichogramma spp.)
  • Cabbage & onion maggots: nematodes
  • Carrot weevils: nematodes
  • Caterpillars: nematodes, larval specific bacteria (Btk), Spined Soldier Bug (Podisus maculiventris); Neem oil organic insecticide;
  • Chinch bugs: Ladybird beetles (ladybugs), Praying Mantids (Tenodera aridifolia sinensis)
  • Citrus weevils: nematodes
  • Cockroaches: nematodes, powdered boric acid with cockroach pheromone to kill; spray containing d-Limonene (orange peel oil) to repel; non-toxic traps
  • Colorado potato beetle larvae: Ladybird beetles (ladybugs), Spined Soldier Bug (Podisus maculiventris)
  • Cucumber beetles: nematodes
  • Cutworms: nematodes, moth egg parasites (Trichogramma spp.)
  • Euopean chafers: nematodes
  • Fall webworms: nematodes, moth egg parasites (Trichogramma spp.); Neem oil organic insecticide;
  • Flea beetles: nematodes
  • Fleas: nematodes
  • Fly larvae: nematodes, fly parasites
  • Fruitworms: moth egg parasites (Trichogramma spp.)
  • Fungus gnats: nematodes
  • Grape root worm: Ladybird beetles (ladybugs)
  • Grasshoppers: grasshopper pathogen Nosema locustae
  • Grubs: nematodes
  • Gypsy moths: Neem oil organic insecticide;
  • Japanese beetles: milky spore powder (Bacillus popillae), nematodes, Neem oil organic insecticide
  • June beetles: nematodes
  • Leafhoppers: Beauveria bassiana GHA strain fungus
  • Leafminers: leafminer parasitic wasp (Diglyphus isaea, Dacnusa siberica)
  • Leafworms: moth egg parasites (Trichogramma spp.)
  • Loopers: nematodes, moth egg parasites (Trichogramma spp.), larval specific bacteria (Bt var. kurstaki), Spined Soldier Bug (Podisus maculiventris)
  • Masked Chafers: nematodes
  • Mealybugs: Mealybug Destroyer (Cryptolaemus montrouzieri), Beauveria bassiana GHA strain fungus; Neem oil organic insecticide;
  • Mites: Ladybird beetles (ladybugs) , Praying Mantids (Tenodera aridifolia sinensis), beneficial mites (Phytoseiulus persimilis, Mesoseiulus longipes, or Galendromus occidentalis), Mealybug Destroyer (Cryptolaemus montrouzieri)
  • Mole Crickets: grasshopper pathogen Nosema locustae
  • Mormon/black field crickets: grasshopper pathogen Nosema locustae
  • Mosquitoes: bacteria Bti (Bacillus thuringiensis var. israelensis)
  • Oriental beetles: nematodes
  • Palmetto bugs: nematodes, powdered boric acid with cockroach pheromone to kill; spray containing d-Limonene (orange peel oil) to repel
  • Plant bugs: Beauveria bassiana GHA strain fungus
  • Psyllids: Beauveria bassiana GHA strain fungus
  • Rose chafers: nematodes
  • Scale: Whitefly Predator (Delphastus catalinae or Eretmocerus eremicus), Ladybird beetles (ladybugs), Red Scale Parasitic wasps (Aphytis melinus); Neem oil organic insecticide; non-toxic traps
  • Scarab beetles: Beauveria bassiana GHA strain fungus
  • Silverfish: nematodes, powdered boric acid with cockroach pheromone to kill; spray containing d-Limonene (orange peel oil) to repel
  • Slugs: non-toxic traps
  • Snails: Decollate Snails (Rumina decollata); non-toxic bait
  • Sod webworm: nematodes
  • Spider Mites: Spider Mite Destroyer (Stethorus punctillum or Neoseiulus californicus)
  • Strawberry root weevils: nematodes
  • Termites: nematodes
  • Thrips: Ladybird beetles (ladybugs), Praying Mantids (Tenodera aridifolia sinensis), Whitefly Predator (Delphastus catalinae), Thrips Mite (Neoseiulus cucumeris or Hypoaspis sp.), Minute Pirate Bugs (Orius sp.), Mealybug Destroyer (Cryptolaemus montrouzieri), Beauveria bassiana GHA strain fungus; Neem oil insecticide; non-toxic traps
  • Weevils: Beauveria bassiana GHA strain fungus
  • Whitefly: Ladybird beetles (ladybugs) , Praying Mantids (Tenodera aridifolia sinensis), Whitefly Parasitic Wasp (Encarsia formosa or Eretmocerus eremicus), Whitefly Predator (Delphastus catalinae), Beauveria bassiana GHA strain fungus
  • Wireworms: nematodes

Information gathered from mail-order companies on the Internet, and catalog for ARBICO Organics, 2008 edition