LIVING WITH THE EARTH. THE TROUBLE WITH PESTS - Moore 1

Transcription

1 LIVING WITH THE EARTH THE TROUBLE WITH PESTS - Moore 1

2 Objectives for this Chapter A student reading this chapter will be able to: 1. Discuss and define the term pest. 2. List, differentiate and classify the major arthropod pests to the Order level. 3. Discuss and describe the general structure and development of insects and arthropod pests. THE TROUBLE WITH PESTS - Moore 2

3 Objectives for this Chapter A student reading this chapter will be able to: 4. List and describe the major arthropod and mammalian vectors of disease including kissing bugs, flies, mosquitoes, fleas, sucking lice, ticks, mites, rats, and mice. 5. Describe and provide specific methods for rodent control. THE TROUBLE WITH PESTS - Moore 3

4 Objectives for this Chapter A student reading this chapter will be able to: 6. Discuss and describe the purpose and function of pesticides and the issues of ecological damage, pesticide resistance, and adverse health effects. 7. List and describe the major classes of arthropod and rodent pesticides, their mechanism of toxicity, and some alternatives to chemical pesticides. THE TROUBLE WITH PESTS - Moore 4

5 THE TROUBLE WITH PESTS INTRODUCTION The prospect of hunger and starvation is a powerful motivation in adjusting attitude towards what is food and what is a pest. THE TROUBLE WITH PESTS - Moore 5

6 WHAT ARE PESTS? Pests are unwanted plants and animals. Any living thing that negatively affects human interests. THE TROUBLE WITH PESTS - Moore 6

7 Human Interests (1) a loss of resources such as agricultural crops, food and property damage, and damage to lawns and gardens; (2) agents of disease; and (3) sources of annoyance and discomfort. THE TROUBLE WITH PESTS - Moore 7

8 WHAT ARE PESTS? The most unwelcome pests from a public health perspective tend to include arthropods and rodents. THE TROUBLE WITH PESTS - Moore 8

9 WHAT ARE PESTS The arthropods (phylum Arthropoda) are invertebrate animals with jointed and paired appendages, a chitinous exoskeleton, and segmented bodies. It is the largest animal phylum with over 700,000 species (Fig. 6-1a,b) THE TROUBLE WITH PESTS - Moore 9

10 From the slide collection of Dr. John Edman, Entomology, Fernald Hall, Umass, Amherst Fig. 6-1a THE TROUBLE WITH PESTS - Moore 10

11 From the slide collection of Dr. John Edman, Entomology, Fernald Hall, Umass, Amherst Fig. 6-1b THE TROUBLE WITH PESTS - Moore 11

12 WHAT ARE PESTS Insects, ticks and mites are involved in the majority of important human vector-borne diseases, and most of these diseases cannot be prevented by vaccines or chemotherapy. THE TROUBLE WITH PESTS - Moore 12

13 WHAT ARE PESTS Early success in the control of insect vectors has been met with reversals as: (1) insects have developed resistance to insecticides; (2) insect control programs have been halted or underfunded; THE TROUBLE WITH PESTS - Moore 13

14 WHAT ARE PESTS Early success in the control of insect vectors has been met with reversals as: (3) the use of less expensive pesticides such as DDT have been reduced because of environmental concerns and political pressures; (4) the combination of poverty and overpopulation has lead to poor sanitation with greater opportunity for insect proliferation; THE TROUBLE WITH PESTS - Moore 14

15 WHAT ARE PESTS Early success in the control of insect vectors has been met with reversals as: (5) destruction of forested areas has eliminated natural insect predators; and (6) climate changes, including warming trends, has promoted increases in some insect populations. THE TROUBLE WITH PESTS - Moore 15

16 What Are Pests? In order to develop workable biological, physical, or chemical controls, it is critical to understand the biology and mechanisms for the spread of disease by these organisms. THE TROUBLE WITH PESTS - Moore 16

17 INSECTS AND OTHER ARTHROPODS General Structure and Development Most insects start their life cycle with the fertilization of an egg, and they pass through either a complete or incomplete metamorphosis. THE TROUBLE WITH PESTS - Moore 17

18 General Structure and Development Incomplete metamorphosis Refers to insects such as roaches, body lice, and grasshoppers, that go through three developmental stages including egg, nymph, and adult stages. THE TROUBLE WITH PESTS - Moore 18

19 General Structure and Development Complete metamorphosis Mosquitoes, flies, and butterflies go through complete metamorphosis and pass through four developmental stages including egg, larvae, pupa, and adult stages. THE TROUBLE WITH PESTS - Moore 19

20 General Structure and Development Molting Exoskeleton Spiracles THE TROUBLE WITH PESTS - Moore 20

21 General Structure and Development The hardened outer body wall of the exoskeleton may be covered with hairs, scales, or spines, and is normally divided into segments joined by flexible intersegmental structures (Fig. 6-2). THE TROUBLE WITH PESTS - Moore 21

22 Fig. 6-2 THE TROUBLE WITH PESTS - Moore 22

23 General Structure and Development Biological Vector In many instances, the microbial disease agents go through a developmental stage in the vector involving sexual reproduction (i.e., malaria). In these instances, the vector is known as a biological vector. THE TROUBLE WITH PESTS - Moore 23

24 Bedbugs and Kissing Bugs Insects belonging to this category have three pairs of jointed legs, sucking mouth parts, wings or wing pads, a segmented proboscis, and belong to the order Hemiptera. THE TROUBLE WITH PESTS - Moore 24

25 Bedbug Bedbugs hide in bedsprings, mattresses, and cracks in the wall coming out at night to feed on humans and warm-blooded animals (Fig. 6-3b). THE TROUBLE WITH PESTS - Moore 25

26 Kissing Bugs The kissing bug is the arthropod vector for American trypanosomiasis or Chagas disease caused by the flagellated protozoan parasite Trypanosoma cruzi (Fig. 6-3a). THE TROUBLE WITH PESTS - Moore 26

27 From the slide collection of Dr. John Edman, Entomology, Fernald Hall, Umass, Amherst Fig. 6-3a THE TROUBLE WITH PESTS - Moore 27

28 From the slide collection of Dr. John Edman, Entomology, Fernald Hall, Umass, Amherst Fig. 6-3b THE TROUBLE WITH PESTS - Moore 28

29 Flies Flies belong to the same order of insects (Diptera) as mosquitoes, Adult flies have one pair of functional wings and three distinct body parts including the head, thorax and abdomen (fig. 6-4). THE TROUBLE WITH PESTS - Moore 29

30 From the slide collection of Dr. John Edman, Entomology, Fernald Hall, Umass, Amherst Fig. 6-4 THE TROUBLE WITH PESTS - Moore 30

31 Flies The common house fly, Musca domestica, is an important vector of infectious disease organisms and foodborne illnesses. THE TROUBLE WITH PESTS - Moore 31

32 Flies Diseases that may be mechanically transmitted by flies include: cholera, bacterial and amoebic dysentery, typhoid and paratyphoid fevers, salmonellosis, hookworm, pinworm, and whipworm. THE TROUBLE WITH PESTS - Moore 32

33 Flies Lay eggs onto garbage, manure, or organic material Undergo complete metamorphosis THE TROUBLE WITH PESTS - Moore 33

34 Flies Biting flies have been responsible for the transmission of a number of diseases including sandfly fever, onchocerciasis (blinding filariasis), African sleeping sickness, deerfly fever ( a form of tularemia), and loaisis (African eyeworm disease). THE TROUBLE WITH PESTS - Moore 34

35 The Control of Flies Elimination of breeding materials Tight fitting screens Air shields DDVP resin strips THE TROUBLE WITH PESTS - Moore 35

36 Mosquitoes Mosquitoes have one pair of wings with scales, belong to the order Diptera (2 wings). Females are characterized by having piercing/sucking mouth parts with an elongated proboscis. THE TROUBLE WITH PESTS - Moore 36

37 Mosquitoes Depending on the species, the eggs may be deposited in still water such as swamps, wet depressions, or in the collected water of old tires or containers. Mosquitoes undergo complete metamorphosis (Fig. 6-5). THE TROUBLE WITH PESTS - Moore 37

38 From the slide collection of Dr. John Edman, Entomology, Fernald Hall, Umass, Amherst Fig. 6-5a THE TROUBLE WITH PESTS - Moore 38

39 From the slide collection of Dr. John Edman, Entomology, Fernald Hall, Umass, Amherst Fig. 6-5b THE TROUBLE WITH PESTS - Moore 39

40 Mosquitoes Once a host is found, the female mosquito takes a blood meal during which time it injects saliva into the skin. The time required for digestion of the blood meal, laying more eggs, and then seeking another blood meal may be as little as two days. THE TROUBLE WITH PESTS - Moore 40

41 Mosquitoes Many of the species of public health interest belong to the genera Anopheles, Culex, and Aedes. Aedes aegypti is an important vector for yellow fever. THE TROUBLE WITH PESTS - Moore 41

42 Mosquitoes Aedes albopictus (Asian Tiger mosquito) inadvertently imported from Japan to Texas. Bites severely, survives cold winters, and is capable of transmitting the agents of dengue fever and dengue hemorrhagic fever, the encephalitides group of viruses, and yellow fever. THE TROUBLE WITH PESTS - Moore 42

43 Mosquitoes Aedes Yellow Fever and Dengue Types Anophelene Malaria Culex Viral Encephalitis THE TROUBLE WITH PESTS - Moore 43

44 Mosquito Control Elimination of stagnant water Carbaryl and Malathion Screens Repellants, DEET (Diethyl toluamide) THE TROUBLE WITH PESTS - Moore 44

45 Fleas Fleas are true insects with three pairs of legs and no wings. THE TROUBLE WITH PESTS - Moore 45

46 Fleas Several species of fleas have the ability to bite humans (Pulex irritans), dogs and cats (Ctenocephalides sp.), and rats (Xenopsylla cheopis) (Fig. 6-6). THE TROUBLE WITH PESTS - Moore 46

47 From the slide collection of Dr. John Edman, Entomology, Fernald Hall, Umass, Amherst Fig. 6-6 THE TROUBLE WITH PESTS - Moore 47

48 Fleas The female flea takes a blood meal from its host, mates, and then lays eggs. eggs drop to the nearest surface such as carpet, or furniture, where they undergo complete metamorphosis to an adult stage within 2-3 weeks. THE TROUBLE WITH PESTS - Moore 48

49 Fleas Their ability to take blood meals and move swiftly among and humans makes them important vectors of disease including plague (Yersinia pestis), murine typhus, tularemia, and even salmonellosis. THE TROUBLE WITH PESTS - Moore 49

50 Fleas The rat flea carries the plague bacillus in its intestinal tract, spreading it from rat to rat and from rat to human (Fig. 6-7). THE TROUBLE WITH PESTS - Moore 50

51 Fig. 6-7 THE TROUBLE WITH PESTS - Moore 51

52 Flea Control Usually in domestic animals and domiciles includes: Pesticidal dusts usually containing carbaryl or methoxychlor THE TROUBLE WITH PESTS - Moore 52

53 Lice Lice have no wings, a dorso-ventrally depressed abdomen (flat), and have legs adapted for clasping hairs and undergo incomplete metamorphosis (Fig. 6-8a,b). THE TROUBLE WITH PESTS - Moore 53

54 From the slide collection of Dr. John Edman, Entomology, Fernald Hall, Umass, Amherst Fig. 6-8a THE TROUBLE WITH PESTS - Moore 54

55 From the slide collection of Dr. John Edman, Entomology, Fernald Hall, Umass, Amherst Fig. 6-8b THE TROUBLE WITH PESTS - Moore 55

56 Lice Three kinds of human lice: The head louse (Pediculis humanis capitis) The body louse (Pediculis humanis corporis) Crab louse (Pthirius pubis). THE TROUBLE WITH PESTS - Moore 56

57 Lice In addition to spreading epidemic typhus, lice also cause trench fever (Rickettsia quintana), and relapsing fever (spirochetes belonging to the genus Borrelia). THE TROUBLE WITH PESTS - Moore 57

58 Roaches Cockroaches are true insects having three pairs of legs, one pair of antennae, and chewing mouth parts (Fig. 6-9). THE TROUBLE WITH PESTS - Moore 58

59 Fig. 6-9 THE TROUBLE WITH PESTS - Moore 59

60 Roaches Undergo incomplete metamorphosis The eggs are usually encased in a capsule and carried for a few days Prefer the dark THE TROUBLE WITH PESTS - Moore 60

61 Roaches No specific disease outbreaks have been attributed to roaches but they may serve as vectors and create a level of discomfort for most people. THE TROUBLE WITH PESTS - Moore 61

62 Roach Control Eliminate food sources Borax powders Organophosphate poison, malathion THE TROUBLE WITH PESTS - Moore 62

63 Ticks and Mites Ticks and mites have four pairs of legs, no antennae or wings, an belong to the class Arachnida. A shorter abdomen and the absence of a constriction between the cephalothorax and abdomen place organisms such as ticks and mites in the order Acarina. THE TROUBLE WITH PESTS - Moore 63

64 Mites Mites do not have a clearly differentiated head, thorax, and abdomen (Fig. 6-10). THE TROUBLE WITH PESTS - Moore 64

65 From the slide collection of Dr. John Edman, Entomology, Fernald Hall, Umass, Amherst Fig THE TROUBLE WITH PESTS - Moore 65

66 Mites The mite Sarcoptes scabiei burrows under human skin to lay its eggs. Mites are transmitted through close personal contact with an infected person. THE TROUBLE WITH PESTS - Moore 66

67 Mites Infestations Dogs develop a condition called mange. Humans develop Scrub typhus, certain forms of hemorrhagic fever, and encephalitis. THE TROUBLE WITH PESTS - Moore 67

68 Mite Control Keep area clean Plenty of sunlight Pyrethrum bomb, and malathion THE TROUBLE WITH PESTS - Moore 68

69 Ticks Belong to the class Arachnida They have four pairs of legs, no antennae, and a fused head, thorax and abdomen (Fig. 6-11). THE TROUBLE WITH PESTS - Moore 69

70 From the slide collection of Dr. John Edman, Entomology, Fernald Hall, Umass, Amherst Fig THE TROUBLE WITH PESTS - Moore 70

71 Ticks are particularly adapted to feed on blood by: (1) the use of barbed feeding organs that pierce the skin to reach the blood and also anchor the tick; (2) a flexible leathery body that easily distends when filled with blood: and (3) uniquely adapted pharyngeal muscles for sucking blood. THE TROUBLE WITH PESTS - Moore 71

72 Two types of Ticks Soft (family Argasidae) Hard (family Ixodidae) ticks THE TROUBLE WITH PESTS - Moore 72

73 Ticks Ticks undergo complete metamorphosis and have a fairly complex cycle such as the deer tick, Ixodes scapularis, which is the vector of lyme disease caused by the spirochete Borrelia burgdorferi (Fig. 6-12). THE TROUBLE WITH PESTS - Moore 73

74 From the slide collection of Dr. John Edman, Entomology, Fernald Hall, Umass, Amherst Fig THE TROUBLE WITH PESTS - Moore 74

75 Ticks A tick may transmit disease Mechanically or Transstudial (tick - egg - tick) THE TROUBLE WITH PESTS - Moore 75

76 Disease Transmitted by Ticks (1) Rickettsial diseases including tularemia, Q fever, and Rocky Mountain spotted fever (2) The disease caused by Borrelia sp. including lyme disease and relapsing fever; (3) viral diseases such as Colorado tick fever,; and (4) bacillus diseases such as Pasteurella tularensis. THE TROUBLE WITH PESTS - Moore 76

77 Tick Control Humans Cover skin when at risk to exposure DEET insect repellant Domestic animals Flea and tick collars THE TROUBLE WITH PESTS - Moore 77

78 Rodents and Pests Rodent Characterisitcs Rats and mice are members of the order Rodentia, which include mammals with teeth and jaws adapted to gnawing. THE TROUBLE WITH PESTS - Moore 78

79 Rodents and Pests The Roof Rat, (Rattus rattus) (Fig. 6-13) Lives in attics or barns Pointed snout Tail longer than it s body Weighs between 8-12oz Length with tail 8-17in THE TROUBLE WITH PESTS - Moore 79

80 Fig THE TROUBLE WITH PESTS - Moore 80

81 Rodents and Pests The Norway Rat, (Rattus norvegicus) (Fig. 6-14) Lives under foundation, along river banks, sewers, between walls Blunt snout Tail shorter than it s body Weighs up to 16oz Length with tail 12-18in THE TROUBLE WITH PESTS - Moore 81

82 Fig THE TROUBLE WITH PESTS - Moore 82

83 Rodents and Pests The House Mouse Lives in close contact with humans (commensal) The Deer Mouse (Peromyscus maniculatis) is a vector of the hanta virus. THE TROUBLE WITH PESTS - Moore 83

84 Importance as Pests and Vectors (1) they harbor a variety of organisms that can produce diseases in humans; (2) they produce crop damage throughout the world; THE TROUBLE WITH PESTS - Moore 84

85 Importance as Pests and Vectors (3) they eat and contaminate food produce and cause structural damage; (4) afflict harm directly by biting humans; and (5) cause extreme discomfort in some people by their visible presence. THE TROUBLE WITH PESTS - Moore 85

86 Rodent Control Establish presence (Fig. 6-16) Rodent Proofing Poisoning or trapping THE TROUBLE WITH PESTS - Moore 86

87 Source: Training materials from HEW Fig THE TROUBLE WITH PESTS - Moore 87

88 PESTICIDES History Pests compete with humans for food, serve as vectors of disease, destroy crops or depress their market quality, cause structural damage to buildings and homes, and attack people directly causing annoyance, injury, or even death. THE TROUBLE WITH PESTS - Moore 88

89 PESTICIDES History 1800s Copper arsenate compounds (Paris Green) and lead arsenate (Bordeaux mixture) were introduced as fungicides and pesticides. WWII DDT THE TROUBLE WITH PESTS - Moore 89

90 PESTICIDES History 1970s Realization of detrimental effects on ecology and human health. THE TROUBLE WITH PESTS - Moore 90

91 PESTICIDES Present Day Problems (1) the resistance of vectors to pesticides; (2) the adverse health and ecological effects of pesticides; and (3) the proliferation of pesticides globally. THE TROUBLE WITH PESTS - Moore 91

92 Insect Resistance From 1970 to 1980, the number of arthropods resistant to insecticides nearly doubled from 224 to 428 while the numbers of resistant species of rodents, bacteria, fungi, and weeds are increasing as well. THE TROUBLE WITH PESTS - Moore 92

93 Insect Resistance Physiological Resistance 1) enzymatic detoxification of pesticides into a less harmful form: (2) reduced permeability of exoskeleton to pesticides; and (3) storage or excretion of pesticides without harm. THE TROUBLE WITH PESTS - Moore 93

94 Insect Resistance Behavioral Resistance (1) landing less frequently or changing landing areas: or (2) avoidance of baits such as fly-paper. THE TROUBLE WITH PESTS - Moore 94

95 The Health and Ecological Effect of Pesticides Humans are exposed to pesticides through: (1) contaminated drinking water; (2) eating foods contaminated with pesticides; (3) pesticide use in the home, garden or lawn: (4) exposure on transcontinental flights; THE TROUBLE WITH PESTS - Moore 95

96 The Health and Ecological Effect of Pesticides Humans are exposed to pesticides through: (5) use in agriculture; (6) in the production of pesticides; and (7) in other occupations. THE TROUBLE WITH PESTS - Moore 96

97 Effects of Pesticide Poisonings Most Acute or one-time exposures Headaches, dizziness, muscular weakness, and fatigue Chronic or low-level pesticide exposure Uncertain, but cancer and/or reproductive are possible problems associated with organochlorine pesticides. THE TROUBLE WITH PESTS - Moore 97

98 Children at Risk Children are exposed to pesticides through: (1) prenatal maternal exposure; (2) food and water sources; (3) presence in agricultural, fields with parents, or working the fields themselves; THE TROUBLE WITH PESTS - Moore 98

99 Children at Risk Children are exposed to pesticides through: (4) contact with residues on parents clothing; or (5) exposure to common household pesticides while in the home (Table 6-1). THE TROUBLE WITH PESTS - Moore 99

100 Adapted from USEPA. 24 Table 6-1 THE TROUBLE WITH PESTS - Moore 100

101 Exposures in LDCs Reasons for higher incidence of pesticide poisonings in LDCs (1) failure to use protective clothing when applying pesticides; (2) workers may be in the field during pesticide spraying; (3) pesticides are being used in LDCs that are banned or severely restricted in the developed countries; THE TROUBLE WITH PESTS - Moore 101

102 Exposures in LDCs Reasons for higher incidence of pesticide poisonings in LDCs (4) pesticide containers are often recycled to store food, milk, or cooking oil; and (5) pesticide products are labeled in languages not readable to the native populations THE TROUBLE WITH PESTS - Moore 102

103 Ecological Concerns Much more than 1.1 billion pounds of pesticides are used in the United States each year with more than five times that amount used globally. THE TROUBLE WITH PESTS - Moore 103

104 Ecological Concerns Pesticide residues, especially of the persistent organochlorines, are now detected in the tissues of animals in virtually every location on earth from the Antarctic to the everglades, small new England streams, to the deepest ocean trenches. THE TROUBLE WITH PESTS - Moore 104

105 Ecological Effects Disrupted the endocrine system of bird, fish, mammals Decreased fertility Increased abnormal behaviors Feminization and Masculinization THE TROUBLE WITH PESTS - Moore 105

106 Types of Pesticides Insecticides (1) act as contact poisons by penetrating the foot pads or body wall; (2) enter the insect breathing pores as a fumigant; (3) act as a stomach poison after ingestion: or (4) desiccate (dryout) the body wall causing it to crack or break. THE TROUBLE WITH PESTS - Moore 106

107 Insecticides Organochlorines Organophosphates Carbamates THE TROUBLE WITH PESTS - Moore 107

108 Organochlorines Dichlorophenylethanes DDT (Fig. 6-19) Bioaccumulation Caused thinning egg shells in fish eating birds THE TROUBLE WITH PESTS - Moore 108

109 Fig THE TROUBLE WITH PESTS - Moore 109

110 Organochlorines Hexachlorocyclohexanes Lindane (Fig. 6-20) Treatment for ectoparasites. THE TROUBLE WITH PESTS - Moore 110

111 Fig THE TROUBLE WITH PESTS - Moore 111

112 Organochlorines Chlorinated Cyclodienes Chlordane (Fig. 6-21) Stomach poisons, fumigants, contact poisons Used against roaches, silverfish ants, and termites. Most were suspended by the EPA in the 1970s THE TROUBLE WITH PESTS - Moore 112

113 Fig THE TROUBLE WITH PESTS - Moore 113

114 Organochlorines Chlorinated Cyclodiene Kepone (Fig. 6-22) Neurological damage among workers in Virginia Chesapeake Bay THE TROUBLE WITH PESTS - Moore 114

115 Fig THE TROUBLE WITH PESTS - Moore 115

116 Organophosphates Parathion (Fig. 6-23) Most likely to be involved with human fatalities. Cholinesterase inhibitors (Fig. 6-24) THE TROUBLE WITH PESTS - Moore 116

117 Fig THE TROUBLE WITH PESTS - Moore 117

118 Fig. 6-24a THE TROUBLE WITH PESTS - Moore 118

119 Fig. 6-24b THE TROUBLE WITH PESTS - Moore 119

120 Carbamates Derivatives of carbonic acid are contact poisons that inhibit cholinesterase in a manner similar to organophosphates. THE TROUBLE WITH PESTS - Moore 120

121 Botanical and Biological Insecticides and other Alternatives Naturally derived alkaloids Bacteria Fungal Spores Integrated Pest Management (IPM) THE TROUBLE WITH PESTS - Moore 121

122 Herbicides Atrazine, alachlor (Fig. 6-25) Destroy the plants by stimulating abnormal growth and interfering with the transport of nutrients. THE TROUBLE WITH PESTS - Moore 122

123 Fig THE TROUBLE WITH PESTS - Moore 123

124 Rodenticides Warfarin (Fig. 6-26) Inhibits prothrombin synthesis. Animal bleeds to death THE TROUBLE WITH PESTS - Moore 124

125 Fig THE TROUBLE WITH PESTS - Moore 125