3/30/2015 Program Overview A review of Beneficial Insects Beneficial roles of insects in a garden ecosystem A little about natural enemies: Predators & Parasitoids Some common & not-so-common beneficial insects Encouraging beneficial insects in the Susan Mahr home garden University of Wisconsin - Madison Most Insects are NOT Bad As Food for Wildlife Over 1 million species worldwide, with over 87,000 species in the U.S. and Canada Only about 1% of all species of insects are serious pests Butterflies Beneficial Activities of Insects Pollinate flowers Many people want to Help decompose dead encourage these insects to visit their plants and animals gardens Kill pest insects 1 3/30/2015 Pollinators Decomposers Bees Break down dead Wasps animals and plants Flies Recycle nutrients Others Natural Enemies Predators Beneficial insects or other organisms that Eat other insects destroy harmful insects Usually larger than their prey Predators eat other insects Parasitoids develop in other insects Consume many prey Pathogens cause diseases in insects Feed as adults and/or immatures Predators Parasitoids Generally fairly mobile Smaller than their host Most have fairly broad host Only the larval stage is range parasitic May be large, conspicuous Immatures develop in/on other insects A single host for development 2 3/30/2015 Parasitoids The Cast of Characters: Some beneficial insects Adults free-living, usually winged and mobile Tend to be host-specific Often small, inconspicuous Praying Mantids True Bugs Order Mantodea Order Hemiptera Generally large Sucking mouthparts Raptorial front legs Simple metamorphosis Many crop pests and some Generalist, opportunistic blood feeders, too Minute Pirate Bugs Big-eyed Bugs Family Anthocoridae Family Lygaeidae 1-2 mm Similar to plant bugs Black and white Feed on mites, small insects Feed on mites, insects eggs and small insects Geocoris spp. Orius species 3 3/30/2015 Perillius bioculatus (twospotted stink bug) Assassin Bugs Stink Bugs Family Reduviidae Family Pentatomidae Relatively large Medium sized Raptorial front legs Green, brown, black Feed on caterpillars, other Produce foul odor when large insects bothered Not all predators; some Includes ambush bugs important pests Feed on caterpillars, beetle Podisus maculiventris larvae and adults (e.g. (spined soldier bug) Colorado potato beetle, Mexican bean beetle), others Beetles Lady Beetles Order Coleoptera Family Coccinellidae Largest group of animals on earth Many species ¼ of all animal species; 40% of all insects Eat soft-bodied insects, especially aphids 30,000 species in North America Complete metamorphosis Larvae often unrecognized Chewing mouthparts Great diversity of lifestyles, includes many predators and a few parasitoids in 40 families Ground Beetles Fireflies Family Carabidae Family Lampyridae 40,000 species worldwide Adults produce light flashes Usually dark colored, nocturnal Larvae feed on slugs Adults feed on caterpillars, grubs, maggots, earthworms Some larvae bioluminescent (= glowworms) Larvae also predaceous 4 3/30/2015 Lacewings and Allies Green Lacewings Order Neuroptera Family Chrysopidae Lacewings, antlions and their relatives Adults have membranous wings Eggs laid on stalks Most are predators Larvae have sickle-shaped mouthparts Mantidflies (Family Mantispidae) are All larvae, some adults predators parasitic within the egg sacs of Feed on aphids, other soft-bodied ground-dwelling spiders insects Adults require honeydew or nectar True Flies Flower or Hover Flies Order Diptera Family Syphidae Complete metamorphosis Adults look like bees Many lifestyles, including predators Larvae look like miniature slugs and parasitoids Larvae eat soft-bodied insects, Predaceous as adults, larvae, or both especially aphids Other Predatory Flies Tachinid Flies Family Tachinidae Bee flies (Family Bombyliidae) 1,300 species in North Longlegged flies (Family Dolichopodidae) America Robber flies (Family Asilidae) All species parasitic Marsh flies (Family Sciomyzidae) Resemble bristly houseflies Most attack caterpillars and beetles Voria ruralis parasitizes cabbage looper 5 3/30/2015 Sawflies, Bees, Wasps, & Ants Order Hymenoptera Predatory Hymenoptera 18,000 species in North America Large wasps in Sphecidae Complete metamorphosis (muddaubers) and Vespidae Various lifestyles, including predators (paper wasps, yellowjackets) and parasitoids Ants The stingless wasps are the largest Feed on caterpillars, various and most important group of natural insects enemies of insect pests Trichogramma Wasps Braconid Wasps Family Trichogrammatidae Family Braconidae Egg parasitoids Small adults with long antennae Very small Attack caterpillars, immatures of Widely used for biological other insects control; several species Many important in agriculture, commercially available especially Aphidiinae Attack eggs of moths and butterflies, beetles, flies, wasps, true bugs Fairyflies (Family Mymaridae) Scelionids (Family Scelionidae) Ichneumonid Wasps Other Important Wasps Family Ichneumonidae Variable in size, but generally larger Family Aphelinidae than braconids Family Pteromalidae Ovipositor often quite long Family Eulophidae Family Encyrtidae Most attack caterpillars and larvae of beetles and sawflies 6 3/30/2015 Other Predatory Arthropods Biological Control Mites Purposeful manipulation of beneficial organisms Spiders – Predators Others – Parasitoids – Pathogens Encouraging Beneficial Reducing Pesticide Impacts Insects in the Garden Learn to recognize pollinators, natural Most insecticides are more toxic to natural enemies, and others and appreciate enemies than to pests their role in the garden ecosystem More selective materials include insecticidal soaps and microbial insecticides Increase garden diversity to provide Many “botanical insecticides” such as alternate food and shelter pyrethrum are directly toxic to natural Incorporate specific flowering plants enemies, but are very short-lived Avoid / reduce broad-spectrum and Use “spot” treatments if possible preventative pesticides Consider cultural controls and other methods besides chemicals as part of IPM Adult Parasitoid Nectar Adult Nectar Resources Resources Various species Annuals, biennials and perennials Small nectaries for small insects! Yarrow (Achillea millefolium) Cilantro (Coriandrum sativum) Large flowers or “platforms” for larger insects Queen Anne’s Lace Alfalfa Yellow rocket Butterflyweed Sweet Alyssum (Lobularia maritima) Dill (Anethum graveolens) Asclepias Daucus carota Medicago sativa Barbarea vulgaris 7 3/30/2015 For More Information For Insect Identification Extension Publications on Biological Control Insect Diagnostic Laboratory – Natural Enemies in Your Garden: A Homeowner’s Guide to Biological Control (MSU) PJ Liesch, Insect Diagnostician – Biological Control of Insects and Mites: An Department of Entomology Introduction to Beneficial Natural Enemies and Their Use in Pest Management. UWEX Pub A3842 1630 Linden Dr. – Alternatives in insect management. NCR Pub 401 (Univ. Illinois) Madison, WI 53706 Articles on the WI MG website (608) 262-6510 wimastergardener.org [email protected] Websites http://www.entomology.wisc.edu/diaglab/entodiag.html – The Pollination Page – pollinator.com/ @WiBugGuy – Pollinator Partnership – www.pollinator.org – Biological Control News website – www.entomology.wisc.edu/mbcn/mbcn.html 8.