Good Bug? Bad Bug? Biocontrol of Insects and Weeds Dr. Meredith Shrader Entomology Extension Agent Tri-River Area Meredith.shrader@mesacounty.us 970.244.1834
Biological Controls Predators Parasitoids Pathogens Nematodes
Good Bugs Lady beetles Ground beetles Lacewings Flower flies Robber flies Mantids Assassin bugs Predatory stink bugs Minute pirate bugs Predatory thrips Predatory mites All spiders
Bad Bugs Aphids Caterpillars Squash Bugs Borers Beetles Earwigs Lygus Stinkbugs Fruit Flies
KNOWLEDGE IS HALF THE BATTLE!!! GO JOE!!!!
Characteristics of Insect Predators Immature stages actively hunt prey Several prey are consumed Adults may or may not have similar food needs as immature form Can only eat so many May not be able to see immediate impact
Adults Eat the Same Thing As Young
Adults and Young Eat Different Food
Hover fly larvae
Adults and Young Eat Different Food
Green lacewing eggs are available from many suppliers that rear/distribute insects
Predatory Mites Female two spotted spider mite and its eggs along with adult predatory mite, Phytoseiulus persimilis. (Photo by Jack Kelly Clark)
Mites Attack
Order Mantodea Mantids
European mantid life stages
European mantid egg cases
Chinese Mantid Tenodera sinensis
Egg cases of the Chinese mantid are sold by some nurseries and in some garden catalogs
Collect egg cases, but keep outside to avoid hatching
European mantid mating pair, 2:30 PM, Mon. Sept. 29, 2008.
European mantid male as lunch, 4:00 PM, Mon. Sept. 29, 2008.
Characteristics of Insect Parasitoids Larvae develop inside their hosts One or more larvae develop in a single host They are invariably lethal to the host parasitoids Adults often have different food needs Nectar, honeydew Pollen
Common Insect Parasitoids Parasitic Hymenoptera Braconid wasps Ichneumonid wasps Chalcid wasps Eulophid wasp Trichogrammatid wasps Parasitic Diptera Tachinid flies
Host evaluation Oviposition Photographs courtesy of Brian Valentine
Tachinid fly eggs on caterpillars and squash bugs
Photograph courtesy of Jim Kalisch
Cabbage looper supporting six developing tachinid fly larvae Tachinid fly pupae within killed cabbage looper larva
Pathogens / Nematodes Fungi Bacteria Viruses Nematodes
Pathogens / Nematodes Advantages Specificity No toxic residues Slower resistance? Compatible with pesticides Applied with pesticide technology Easily modified genetically
Pathogens / Nematodes Disadvantages Specificity Short shelf life and field persistence High population density optimal for spread Affected by weather Slow acting Cadaver residues contaminate produce Commercial development difficult
Some Important Fungi and Common Hosts Entomophthora muscae* - flies Erynia neoaphidis - aphids Beauveria bassiana - many insects Metarhizium anisopliae many insects Coelomomyces spp. - mosquitoes, bugs Hirsutella thompsonii - mites Verticillium lecanii - aphids Nomurea rileyii - caterpillars Paeciliomyces fumosaroseus - bugs
Nematodes steinernema and heterorhabditis Peach Tree Borer White Grubs Caterpillars 10 Acres (500 mill)- $270.00 Crop(s) Targeted Pest Common Name Efficacious Nematodes2 Artichokes Artichoke plume moth Sc Vegetables Armyworm Sc, Sf, Sr Turf Billbug Hb,Sc Turf, vegetables Black cutworm Sc Berries, ornamentals Black vine weevil Fruit trees, ornamentals Borer Hb, Sc, Sf Home yard, turf Cat flea Sc Pome fruit Codling moth Sc, Sf Vegetables Corn earworm Sc, Sf, Sr Vegetables Corn rootworm Hb, Sc Cranberries Cranberry girdler Sc Turf Crane fly Sc Citrus, ornamentals Diaprepes root weevil Hb, Sr Mushrooms Fungus gnat Sf, Hb Grapes Grape root borer Hz, Hb Vegetables, Leafminer Hb, Hd, Hm, Hmeg, Sc, Sg Sc, Sf ornamentals Fruit trees Plum curculio Sr Turf, ornamentals Scarab grub3 Hb, Sc, Sg, Ss, Hz Ornamentals Shore fly Sc, Sf
Conserving and Enhancing Natural Enemies Don t kill them Limit use of broad spectrum insecticides Provide foods that the adults need Often need nectar, pollen Good Bug Power Blend is a combination of yellow, red, crimson, rose, and white clovers, grizzly alfalfa, white alyssum, nasturtium, white yarrow, carrot, dill, daikon radish, and celery seeds. Provide foods that the immature stages need Allow there to be some hosts, prey available
Some Plants Useful for Providing Food for Adult Predators Umbelliferae/Apiaceae - (dill, fennel, etc.) Yarrow Many sedums Spurges* Alyssum Basket-of-gold Thyme, several herbs
What to Release?? Inundate Acts like a spray No long term beneficial populations Fast results in pest population decline Inoculate Small amount released Biocontrol population increases, feeds slowly on pest Residual population to control pest
What to Release and When Lots of biocontrol agents can be purchased online May be expensive Biocontrol may be specialized; egg vs larvae Release before pest population reaches damaging levels
Plan Ahead!! USPS Tracking page should not be a bookmark May take time to arrive or hatch Feed 1-3 weeks before pupation Adults may not eat target pest Initial release followed by additional releases 3-4 weeks later
Two-Year-Old Effect Can t make them stay where you released them Your house!! Neighbors house!!
Plant Refugia Within Fields Insects Don t Move Far *Research on beneficial insect movement
Movement??
-Planning -Planting -Flowering when pest present Can do in orchards, gardens and large acreage commercial row crops
Cons to Refugia Planting Attracts ALL bugs, not just good ones Plants may move outside of planting area Water requirements increase Some seed maybe costly Variety of seeds needed to keep adult beneficial insects around- prolonged flowering period
Weed Control Palisade Insectary
Palisade Insectary Call to purchase Only for Colorado residents Can be in high demand Can be expensive Proper release for beneficial organisms May not give 100% control; puncturevine weevil May take several years; Tamarisk beetle
Alternatives To Conventional Herbicide Burning Vinegar (20%) Hoeing Discing Mowing Manual hand removal Plant competition Cover crop
Thank you