Hello this assignment is not that complicated you just have to find the answers from the slide of week 5 and week 6 that I have attached. I have also attached the assignment question paper . this assi

Copyright © 2017 by Nelson Education Ltd. Chapter 23 Pest Management Copyright © 2017 by Nelson Education Ltd. Key Concepts ▪ Types and uses of pesticides ▪ Advantages and disadvantages of modern pesticides ▪ Regulation of pesticides ▪ Alternatives to conventional pesticides 2 Copyright © 2017 by Nelson Education Ltd. How D oes N ature K eep P est P opulations U nder C ontrol ? ▪ Pest – An organism that interferes with human activity – Situation- and opinion- dependent definition ▪ Natural C ontrols – Predators, parasites, disease 3 Copyright © 2017 by Nelson Education Ltd. What A re Pesticides? ▪ Chemicals designed to kill pest organisms – Insecticides – Herbicides – Fungicides – Rodenticide ▪ Biocide : Kills species other than target ▪ Plants have been making their own pesticides for millennia . 4 Copyright © 2017 by Nelson Education Ltd. First - G eneration Pesticides ▪ Sul ph ur , lead, arsenic, mercury – Nondegradable inorganic toxins ▪ Plant extracts – F o r example, pyrethrum , rotenone 5 Copyright © 2017 by Nelson Education Ltd. Second - G eneration Pesticides ▪ Primarily synthetic organic compounds ▪ Persistence varies from days to years ▪ Some common types – Chlorinated hydrocarbons – Organophosphates – Carbamates – Botanicals – Microbotanicals 6 Copyright © 2017 by Nelson Education Ltd. DDT: The F irst Second - G eneration P esticide ▪ Broad spectrum pesticide ▪ Persistent : Not readily degraded ▪ Water-insoluble, so retained on crops ▪ Fat-soluble, causing bioaccumulation ▪ Genetic resistance in insects 7 Copyright © 2017 by Nelson Education Ltd. ▪ Thinned eggs in peregrine falcons ▪ Killed beneficial insects ▪ Banned in North America in 1972 ▪ Still used in countries to combat malaria 8 DDT: The F irst Second - G eneration P esticide Copyright © 2017 by Nelson Education Ltd. The Case For Pesticides ▪ Save human lives from pest-transmitted disease ▪ Increase food supplies ▪ Increase profits for farmers ▪ Work faster and better than alternatives ▪ Health risks low vs. benefits with proper use ▪ Newer pesticides becoming safer, more effective 9 Copyright © 2017 by Nelson Education Ltd. What I s the I deal P esticide ? ▪ Affects only target pests ▪ Does n ot allow pests to evolve immunity ▪ Rapid breakdown to harmless byproducts after use ▪ Affordable and cost-effective 10 Copyright © 2017 by Nelson Education Ltd. The Case Against Pesticides : What Is the M ajor P roblem W ith U sing P esticides ? ▪ Promotes evolution of genetic resistance by selecting members of population with genetic immunity ▪ Especially a concern for species that reproduce quickly 11 US Department of Agriculture Copyright © 2017 by Nelson Education Ltd. ▪ Wipe out natural predators – Create new pest species – Increase populations of existing pests ▪ Migrate into the natural environment ▪ Harm to other wildlife or human health The Case Against Pesticides: What Are Other Problems With Using Pesticides? 12 Copyright © 2017 by Nelson Education Ltd. How S uccessful H ave P esticides B een in R educing C rop L oss ? ▪ Six percent more of the U.S . food supply is lost to pests today than in the 1940s . ▪ Losses due to insects have doubled since 1942 despite 10x more insecticides . ▪ For every $1 spent on pesticides, there is $ 5–$10 in environmental damages . ▪ Pesticide use can be reduced without affecting yield . 13 Copyright © 2017 by Nelson Education Ltd. How A re P esticides R egulated in Canada? ▪ Federal – 2006 Pest Control Products Act (PCPA) – Regulates manufacture, import, sale, or use ▪ Provincial – Use, storage, and disposal regulations ▪ Municipal – Residential- and cosmetic-use restrictions in 75 municipalities (2006) 14 Copyright © 2017 by Nelson Education Ltd. What S hould B e the P rimary G oal of P est C ontrol ? ▪ Reduction not eradication ▪ Economic T hreshold – Point when losses due to pests outweigh cost of pesticide use – Preferred over insurance threshold or cosmetic spraying 15 Copyright © 2017 by Nelson Education Ltd. Alternatives to Conventional Chemical Pesticides ▪ Adjusting cultivation practices – Crop rotation – Companion planting ▪ Genetic engineering for pest resistance ▪ Biological pest control ▪ Insect birth control, pheromones, hormones ▪ Hot water or insecticidal soaps 16 Copyright © 2017 by Nelson Education Ltd. Biological Pest Control ▪ Spider populations – Kill more insects worldwide than combined insecticides – Can be encouraged when farmers build hibernation huts ▪ Bacillus thuringiensis (Bt) – Occurs naturally in soil, plants, caterpillars – Concentrates the toxins from Bt into a spray • Import natural predators, parasites, diseases specific to the pest 17 Copyright © 2017 by Nelson Education Ltd. Hormones and the Insect Life Cycle ▪ Normal growth and development requires juvenile hormones ( JH ) and moulting hormones (MH ). ▪ Synthetic hormones disrupt this cycle when applied at the correct time . 18 Copyright © 2017 by Nelson Education Ltd. Hormones and the Insect Life Cycle Normal hornworm Hornworm treated to prevent production of MH 19 Agricultural Research Services/USDA Copyright © 2017 by Nelson Education Ltd. Integrated Pest Management (IPM) ▪ Ecological system approach ▪ Reduce pest populations to economic threshold ▪ Field monitoring of pest populations ▪ Preferential use of biological agents before synthetic 20 Copyright © 2017 by Nelson Education Ltd. IPM Examples Spruce budworm control – Natural predators – Biological agents (e.g ., Bt) – Selective harvesting Gypsy moth control – Natural predators – Pheromones – Biological agents – Synthetic insecticides Fig. 23-10 Fig. 23-11 21 Dion Manastyrski © BC Ministry of Forests © Neil Hardwick/Alamy Copyright © 2017 by Nelson Education Ltd. Spotlight : Mountain Pine Beetle s ▪ Removal of infested trees ▪ Trapping using pheromone mimics ▪ Signalling trees as not-worth-invading using beetle pheromone mimics ▪ Controlled burn of badly infested patches ▪ Treat trees with chitosan, an ecofriendly biopesticide ▪ Limited spraying with insecticides. 22 Copyright © 2017 by Nelson Education Ltd. Why I s IPM N ot M ore W idely u U sed ? ▪ Requires expert knowledge ▪ Slower than conventional pesticides ▪ Method development is site-specific ▪ Initial costs may be high . ▪ Gov ernment subsidies favour conventional pesticides . 23 Copyright © 2017 by Nelson Education Ltd. Strategies for IPM P romotion ▪ Tax pesticides to fund IPM research ▪ Government-funded demonstration projects ▪ Send experts onto farms for dialogue ▪ Special crop insurance for IPM ▪ Ecologo labelling ▪ Remove subsidies that favour conventional pesticides 24 Copyright © 2017 by Nelson Education Ltd. Conclusion ▪ Pests are part of an ecosystem . ▪ Controlling them means manipulating ecosystems, with unintended consequences . ▪ Insecticides offer a limited solution . ▪ IPM strategies may yield better results . 25