森林病虫害防治的基本原则(英文版).ppt

objectives of forest insect management at the end of this section students should be able to: have an understanding of the following ecological processes, concepts and pest management strategies. the dynamic events associated with forest succession and the role of forest insects in the process. the basic differences between forest insect management on federal forest lands versus on private lands. the mortality quotient and the concept of economic damage. the different insect pest management strategies including mechanical and physical control, chemical control, biological control, and some alternative methods of insect control. the kinds of insecticides used in applied control and the different formulations of those chemicals. the basic differences between density dependent and density independent control.,principles of forest insect pest management,hickory horned devil,regal moth - adult of hickory horned devil,philosophy of forest management 1) federal/state/county lands 2) industrial and private forestry,philosophy of forest management federal/state/government lands: focus on ecosystem preservation approaches: establish forest preserves long rotations encourage recreation use protect biodiversity protect endangered species,philosophy of forest management industrial and private lands: focus on intensive forestry approaches: genetic improvement short rotations thinning and pruning new technology in wood utilization and harvesting,long range forest management goals federal forestry: maintaining forest health industrial and private forestry: protecting investments,ecological roles of insects: herbivores defoliators gypsy moth predators checker beetles mantids prey southern pine beetles, aphids detritivores termites, borers vectors elm beetles & ded pollinators,what is a pest? pest status depends on population levels economic factors & objectives of stand. (it is not your younger sibling),some review terms: equilibrium position - the average population level of an insect species (ep). economic threshold - the population level at which management action should be taken to prevent the pest from reaching the economic injury level (et). economic injury level - the lowest number of insects that will cause economic damage (eil). economic damage - the amount of pest-caused damage that justifies the cost of applying pest control measures (ed).,some insects are never economic pests - the equilibrium position (ep) is below the economic threshold (et) or economic injury level (eil) example: eastern tent caterpillar,some insects are occasional pests and must be controlled at et or they will reach eil. example: spruce budworm, douglas-fir tussock moth,some insects are regular and serious pests the equilibrium position (ep) is above eil all the time unless steps are taken to keep them low. example: seed and cone moths in seed orchards,economic considerations in pest management include: value of crop 2) cost of control 3) pest status - depends on point of view,approaches to pest management: mechanical control chemical control biological control integrated pest management,1)mechanical control: fly swatters,1) mechanical control:,fly swatters,salvage logging,sanitation,water treatment of cut logs,kiln drying of lumber,2) chemical control: effects on insects and humans,characteristics of pesticides:,specificity range of action,persistence how long does it last?,toxicity how dangerous?,measures of toxicity,ld 50 dose (mg/kg) lethal to 50% of test population - oral or dermal,pesticides are poisons!,“everyday toxins”,acute oral ld 50s (mg/kg),* for a 170 lb. male,mode of action of pesticides:,stomach poisons bacillus thuringiensis,contact poisons - malathion,systemics - temik,fumigants methyl bromide,repellents n,n-diethyl-meta-toluamide,attractants fire ant baits,insecticide chemical groups:,nicotine tobacco plants pyrethrum - chrysanthemums rotenone tropical derris plants,characteristics: quick knock down short residual time expensive,a) botanicals,b) organochlorines - also called chlorinated hydrocarbons ddt methoxychlor lindane chlordane aldrin, dieldrin, endrin,characteristics: generally have long residue toxicity varies greatly,c) organophosphates - malathion, parathion all are cholinesterase inhibitors,characteristics: generally very effective toxicity varies greatly - (oral ld 50 malathion 1375, parathion 2 mg/kg) short residual,cholinesterase inhibition,d) carbamates: carbyaryl (sevin) or carbofuran (furdan) *cholinesterase inhibitors,characteristics: generally quite effective generally less toxic than op carbofuran is exception - oral ld 50 8 mg/kg residual limited, but longer than op,e) synthetic pyrethroids ambush, warrior t, pounce,characteristics: much more effective than natural pryrethrum used at very low rates relatively safe - ld50 about 250 mg/kg resistance by insects has become a serious problem,formulation and application of insecticides: sprays dusts wettable powders (wp) emulsifiable concentrates (ec) ultra low volume sprays (ulv),pesticide safety keep away from children read the label legal contract between the user, the producer and the state and federal governments remember these are poisons!,insect growth regulators: development juvenile hormone (jh) methoprene. synthetic ecdysone interferes with normal development cuticle formation - diflubenzuron disrupts cuticle formation, inhibits molting process,behavioral chemicals = semiochemicals pheromones = chemicals used for communication within species sex pheromones aggregation pheromones anti-aggregation pheromones,behavioral chemicals = semiochemicals specific insect pheromones collected, analyzed and synthesized. synthetic pheromone impregnated into rubber septum. wendell roel of (cornell university) did much of the pioneering work in this field.,pheromone may be used in insect control and pest management: 1. detection and monitoring 2. trap outs protection 3. attracticides 4. confusants,1. detection and monitoring: turf beetle,2. trap outs /protection: german bark beetles,3. attracticides: pheromone plus insecticide insects are attracted to the material and killed. many ants are killed in this manner; amdro, etc.,4. confusants: german grape berry moth,biological control: a)action of natural enemies b)predators c)parasites (parasitoids) d)pathogens,biological control: usually density dependent - the percentage of hosts killed increases with population density in contrast, natural control factors (like weather) are density independent kill the same percentage of the pests regardless of population density,native and introduced biological control agents predators preying mantids lady bird beetles (ladybugs) lacewing larvae and adults ground beetles,lacewing adult,preying mantid,lady bird beetle (ladybug),larva eating aphids,parasitoids chalcid wasps cynipid wasps ichneumonid wasps numerous diptera,value of parasitoids vs. predators parasitoids generally very host specific well synchronized with host biology predators not host specific, can switch prey when food is scarce populations do not die out when one prey is gone,pathogens bacteria bacillus thuringiensis, bt controls many insect pests fungi entomophthorales spp. infects gypsy moth larva viruses npv nuclear polyhydrosis virus (gypsy moth & other larva). gv granulosis virus (douglas-fir tussock moth) protoza nosema fall webworm,approaches to biological control importation from other countries conservation that protect habitats of any biocontrol agents that may be present enhancement: artificial rearing of agent for release to increase or “enhance” existing biocontrol populations,advantages of biological control control is self-perpetuating control is selective and density dependent does not create new problems - normally,disadvantages of biological control not effective against direct pests where any damage is unacceptable some level of damage occurs and must be acceptable must be implemented over large areas may take years to become effective,other approaches to insect control: host resistance- preference/non-preference antibiosis tolerance -,other approaches to insect control: legislative control: laws made to prevent entry or spread of pests. quarantine against pine shoot borer.,integrated forest pest management,“the combination of all suitable techniques to reduce or manipulate pest populations so that they remain below economically important levels”,questions to for principals of forest insect management: 1) what are the basic differences in management philosophy between those in federal forestry and the private forestry companies? 2) why is control of seed orchard pests so i