1、Biorational Insecticides in the Landscape and Options for Turf Insect Pest Management,Eileen A. Buss, Ph.D. Associate Professor 352-273-3976,Learning Objectives,Define “biorational insecticide” Know the differences between conventional & biorational insecticides Know the strengths / weaknesses of th
2、e different biorational insecticides Be able to give a range of control options to your clients,Traditional Insecticides (Organophosphates & Carbamates),Broadly toxic Affect systems common to both insects and vertebrates (e.g., nervous system) Risk to non-target organisms (e.g., beneficial insects,
3、fish, birds, humans) Secondary pest outbreaks Pest resurgences and resistance,What is a “Biorational” Insecticide?,An insecticide of natural origin that has little or no adverse effects on the environment or non-target organisms,How are Biorationals Different from Conventional Insecticides?,Differen
4、t modes of action Low use rate More selective Short residual activity Low risk to humans, wildlife, and environment,Types of Biorational Insecticides,Botanicals Azadirachtin/neem, rotenone, sabadilla, pyrethrins/ pyrethrum, nicotine Microbials Bacteria, fungi, nematodes Protozoa and viruses not comm
5、ercially available Others Insect growth regulators, molt accelerating compounds, soaps, oils,Natural plant products extracted from commercially-grown plantsExamples: azadirachtin/neem, rotenone, sabadilla, pyrethrins/pyrethrum, nicotine,Botanical Insecticides,Azadirachtin / Neem,From seeds of the tr
6、opical neem tree Broad spectrum (e.g., caterpillars, leafminers, thrips, whiteflies, mealybugs) Active by contact or ingestion Feeding deterrent, interferes with molting in young insects, Trade names: Margosan-O, Azatin, Bio-neem (used in greenhouses, landscapes),Rotenone,Toxic alkaloid extracted fr
7、om roots of a tropical legume Used in garden dusts, flea powders Very toxic to fish,Sabadilla,From seeds of the sabadilla lilly Trade names: Red Devil, Natural Guard No residue; breaks down quickly in light Target pests: caterpillars, leafhoppers, stink bugs, squash bugs, thrips Crop: vegetables, ci
8、trus, avocado, mango,Pyrethrum, Pyrethrins,Derived from chrysanthemum flowers Low mammalian toxicity Rapid “knockdown” of flying insects; paralyzes CNS Synergized by piperonyl butoxide (PBO) Breaks down quickly in sunlight; no residual Expensive, but widely used,Pyrethroids (Group 3),Synthetic versi
9、ons of pyrethrum, but with enhanced properties Fast-acting, good knockdown Low mammalian toxicity; target selective for insect nerves Broadspectrum contact insecticides used against surface-feeding insects and mites (not systemic) Usually applied at low rates on foliage or as root drenches in nurser
10、ies,Pyrethroids,Pyrethroids are generally not compatible with biocontrol programs (toxic to hymenopterans) Pyrethroids have been associated with secondary pest outbreaks (e.g., spider mites), which results in more pesticide use to control those outbreaks Pyrethrins and older pyrethroids exhibit grea
11、ter toxicity at cooler temperatures; newer pyrethroids are more toxic at higher temps,Movement of Pyrethroids,Not very water soluble Pyrethroids will bind to surfaces rather than run off However, with their widespread use, several pyrethroids have been detected in California surface waters (Weston e
12、t al. 2004),Microbial Insecticides,Products that contain pathogens or microbially-derived toxins or by-products that kill insects Bacteria Fungi Nematodes (not really a microbe) Protozoa Viruses,Bacterial Insecticides,Spore-forming, rod-shaped bacteria in the genus Bacillus Commonly occur in soils M
13、ust be eaten to be effective,Bacillus thuringiensis (Bt),Bt var. kurstaki - used since 1950s to control leaf-eating caterpillars Produced commercially by fermentation Very low vertebrate toxicity Short residual in sunlight Works better against small larvae than vs. larger ones,Other Bt strains are a
14、ctive against insects other than Lepidoptera (e.g., M-one for Colorado potato beetle control Bt var. san diego; Bt var. israelensis to kill mosquito, fungus gnat, and black fly larvae),Milky Spore Disease (Bacillus popilliae),Diseased (left) and normal (right) grubs,Dan Potter, Univ. of KY,Conserve
15、SC (Spinosad),Soil-dwelling bacterium, Saccharopolyspora spinosa Contact and stomach poison Residual up to 2 weeks Caterpillars, thrips, fire ants Labeled for use on greenhouses, nurseries, and all turfgrasses,Avid (Avermectin),Produced from Streptomyces avermitilis Slow acting Low mammalian toxicit
16、y Leaf systemic Mites and leafminers,Fungi,Spores grow on the insect cuticle, then hyphae penetrate the cuticle and grow inside the body, soon killing the insect,Fungus infected chinch bug (left) & whiteflies (right),Metarhizium anisopliae,Called “green muscardine disease” The cadavers cuticle becom
17、es red. In high humidity, a white mold grows on the cadaver, which turns green as spores are produced. Fungus is naturally in soil & infects insects Infects 200 arthropod species (used for ticks, beetles, flies, gnats, thrips), but is safe for use around mammals,Beauveria bassiana (Naturalis T, Bota
18、nigard),Called “white muscardine disease” Used for aphids, whiteflies, mealybugs, mealybugs, ticks, beetles, flies, gnats, thrips Greatest mortality in hot and humid conditions Fungi do not need to be ingested to work Infected insects die within a few days to a week Avoid tank-mixing with fungicides
19、,Improving the Chance of Infection,Use of an abrasive (e.g., diatomaceous earth) along with Beauveria may increase insect mortality by weakening the insect cuticle,Entomopathogenic Nematodes,Microscopic, unsegmented worms Attack various insects (e.g., soil insects, wood borers) Enter hosts body thro
20、ugh mouth and spiracles, release and feed on bacteria, reproduce inside insect body Dont damage plants have different mouthparts,Entomopathogenic Nematodes,Several species (Steinernema spp., Heterorhabditis spp.) occur naturally in the soil, but some can be purchasedSome insecticides, like imidaclop
21、rid (Merit), may slow grub behavior down and make them more susceptible to nematode infection,Molt-Accelerating Compounds,Mimic the action of the insect molting hormone, ecdysone (Mach 2, Confirm)Low vertebrate toxicityIngestion forces a premature, lethal molt of turf grubs and caterpillars,Chitin S
22、ynthesis Inhibitor,Talus IGR (buprofezin) Active by contact, ingestion, or vapor Target pests: mealybugs, whiteflies, scales, leaf- and plant hoppers Sites: greenhouse, nurseries, ornamentals, fruit and nut trees,Horticultural Oils,Highly refined petroleum-based oils Useful vs. small or slow-moving,
23、 soft-bodied pests, (aphids, leafhoppers, scales, overwintering eggs, mites) May prevent gas exchange through egg membranes, clog insect mouthparts, deter feeding or egg-laying,Horticultural Oils,Advantages: Non-toxic to vertebrates No resistance Disadvantages: Must contact insect with spray No resi
24、dual Potential for phytotoxicity,Phytotoxicity,Insecticidal Soaps,Made from salts in the fats and oils of animals and plants (very safe)Kill by disrupting insect cuticleContact toxicity only no residualGood vs. small, soft-bodied insects (aphids, caterpillars, crawlers)M-Pede, Rose and Flower Insect
25、 Control, and Safer Yard & Garden,Insecticide Options for Turf Pests,Caterpillar Control Options,* Trade names are only used as examples and are not intended as endorsements. Other products may be labeled against this pest group.,Chinch Bug Control Options,* Trade names are only used as examples and
26、 are not intended as endorsements. Other products may be labeled against this pest group.,Grub Control Options,* Trade names are only used as examples and are not intended as endorsements. Other products may be labeled against this pest.,Mole Cricket Control,Preventive: Treat young nymphs in May/Jun
27、e, soon after peak egg hatch Chipco Choice/TopChoice, pyrethroids, neonicotinoids, combination productsCurative: Treat after damage occurs, usually summer, fall, or spring Baits (Dursban, Advion) Spot treatments (Orthene, others),If a tree falls in the forest and no one is around to hear it, does it
28、 make a sound?,Do insecticides work if there are no insects present to control?,What should we recommend?,Determine the clients goals and any site limitations (e.g., proximity to water, lack of irrigation, steep slope) Rule out or consider non-chemical options first Several products may have similar efficacy against certain pests Product cost is a major factor,
