Insects, Diseases, and Animals

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Insects, Diseases, and Animals

• Jeffery K. Tomberlin, Ph.D.
• Assistant Professor Extension Specialist
• Texas Cooperative Extension
• Texas AM University

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Insects The Good, The Bad, The Ugly
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Diversity of Life
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Linneaus

• Systema Naturae (1758)
• Kingdom
• Phylum
• Class
• Order
• Family
• Genus
• Species

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Basic Classification of Life

• Kingdoms
• Animalia (multicellular)
• Protista (unicellular eukaryotes)
• Plantae (plants)
• Monera (algae)
• Fungi (mushrooms)

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What are Insects?

• Kingdom Animalia
• Phylum Arthropoda
• Class Insecta
• Species ????

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What are Insects?

• Kingdom Animalia
• Phylum Arthropoda
• Class Insecta
• Species ????

• Characteristics
• Six legs
• Bi-lateral symmetry
• Three body parts
• Exoskeleton

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Insect Diversity

• -33 Orders
• -750,000 species world-wide

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Benefits of Insects

• Food chain

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Benefits of Insects

• Food chain

Start
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Insects Associated with Disease????
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Insects as Direct Agents of Disease and Discomfort

• -Entomophobia Delusory parasitosis

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Insects as Direct Agents of Disease and Discomfort

• -Entomophobia Delusory parasitosis
• -Annoyance

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Insects as Direct Agents of Disease and Discomfort

• -Entomophobia Delusory parasitosis
• -Annoyance
• -Accidental

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Insects as Direct Agents of Disease and Discomfort

• -Entomophobia Delusory parasitosis
• -Annoyance
• -Accidental
• -Envenomization

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Insects as Direct Agents of Disease and Discomfort

• -Entomophobia Delusory parasitosis
• -Annoyance
• -Accidental
• -Envenomization
• -Dermatosis

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Insects as Direct Agents of Disease and Discomfort

• -Entomophobia Delusory parasitosis
• -Annoyance
• -Accidental
• -Envenomization
• -Dermatosis
• -Myiasis

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Insects as Direct Agents of Disease and Discomfort

• -Entomophobia Delusory parasitosis
• -Annoyance
• -Accidental
• -Envenomization
• -Dermatosis
• -Myiasis
• -Allergies

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Insects as Direct Agents of Disease and Discomfort

• -Vectors

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Insects as Direct Agents of Disease and Discomfort

• -Vectors
• -Mechanical
• -Equine infectious anemia
• -Polio
• -Plant viruses

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Insects as Direct Agents of Disease and Discomfort

• -Vectors
• -Mechanical
• -Equine infectious anemia
• -Polio
• -Plant viruses
• -Obligatory
• -Malaria
• -Equine encephalitis

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Insects as Direct Agents of Disease and Discomfort

• -What organisms do they vector?
• -Viruses (arboviruses)
• -Bacteria (Lyme disease)
• -Protozoa (Malaria)
• -Nematodes (Onchocerciasis)

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Insects Associated with Disease

• -Flies (Diptera)

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Insects Associated with Disease

• -Flies (Diptera)
• -Bugs (Hemiptera)

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Insects Associated with Disease

• -Flies (Diptera)
• -Bugs (Hemiptera)
• -Fleas (Siphonaptera)

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Insects Associated with Disease

• -Flies (Diptera)
• -Bugs (Hemiptera)
• -Fleas (Siphonaptera)
• -Lice (Phthiraptera)

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Diptera

• Flies

-120,000 species -Disease transmitters -Aquatic
and terrestrial
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Diptera
-120,000 species -Disease transmitters -Aquatic
and terrestrial -Holometabolism -One pair of
wings halteres

• Flies

Diseases???
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Sites Attacked By Flies
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Three Primary Fly Pests

• House fly
• Stable fly
• Horn fly

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House fly, Musca domestica
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Horn fly, Haematobia irritans
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Insect Life Cycle
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Horn fly, Haematobia irritans

• 1 pest affecting cattle
• Both sexes feed multiple times daily
• Reside on cow
• Consume 10 µl/day 3000/cow30 ml/day
• Bites hurt
• Cosmetic defects

Biology 1
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• Nursing cows
• Metabolism of cow
• Reduce feeding

Economic Threshold250 flies/cow
Biology 2
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Effects on weight gain
Horn fly s in Texas
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Stable Fly, Stomoxys calcitrans
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Insect Life Cycle
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Where Are The Breeding Sites For Stable Flies?
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Stable fly, Stomoxys calcitrans

• More abundant in confined areas
• Attack many areas sides, back, primarily legs
• Both sexes feed once/day
• Do not reside on cow
• Bites hurt result in wound
• Reduced feeding

Economic Threshold 2-4/leg
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Greene et al. (Kansas State University)
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Greene et al. (Kansas State University)
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Greene et al. (Kansas State University)
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Mosquitoes?
-How do they transmit diseases?
-Practically everywhere -Tropics primarily -100
viruses
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Mosquitoes

• Larvae live in water (standing)
• Can enter diapause
• Adult females bite day or night
• Transmit filarial worms, viruses, and protozoa

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Mosquitoes

• -Major problems
• Malaria -300 to 500 million cases annually
• -1 million deaths annually
• -Colonial time
• Yellow Fever -1905 New Orleans
• Dengue Fever -1995 Texas

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Mosquitoes

• -Major problems
• Malaria
• Yellow Fever
• Dengue Fever
• -How do we treat?

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Methods of Control for our problem aquatic
insects?

• Bt dunks

6.00/packet
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Methods of Control for our problem aquatic
insects?

• Bt dunks
• Dumping containers

Or screen buckets
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Methods of Control for our problem aquatic
insects?

• Bt dunks
• Dumping containers
• Community spray project

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Mosquitoes

• Why are they still a problem?

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Mosquitoes

• Why are they still a problem?
• -secondary hosts
• -sexual transmission
• -diapause

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Blackflies?
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Blackflies

• Larvae live in water (running)
• Adult females are blood-feeders
• Distributed anywhere with running water (even
  frozen)
• Day feeders

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What Pathogens are Associated with Blackflies?

• -Black fly fever
• -River blindness (filarial worm) 17 million
  infected
• -Mansonellosis (tropical)
• -Painful bites (asphyxiation)
• -Bovine onchocerciasis (Africa)
• -Leucocytozoonosis (U.S.) similar to malaria

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Sandflies and Tabanids?
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Sandflies and Tabanids

• -Larvae in moist
• substrate
• -Feed on organic matter
• -Adults are day feeders
• -Females need blood

-Larvae are in muddy or wet areas -Razor sharp
mandibles -Adults are day feeders -Females only
on blood
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Sandflies and Tabanids

• Annoyance
• Transmit filarial worms or anthrax
• Common sandfly species develop in tree holes
  (water source)
• Bluetongue (virus)
• Hemorrhagic disease

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Phthiraptera
-3,000 species -dorso-ventral flattened -Hemimetab
olism -Diseases?

• Lice

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Phthiraptera

• Lice

-Taxonomy Two Groups Anoplura Mallophaga
Anoplura Obligate blood-feeders on
mammals Mallophaga Are more diverse and will
colonize mammals, birds, marcupials Which is
more important?
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Phthiraptera

• Lice

Anoplura -Vessel feeders (solenophages) -Typically
host specific (head vs crotch) -Must have blood
meal -Symbionts present in gut -Transferred
transovarial
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Phthiraptera

• Lice

Mallophaga -Head much broader than Anoplura -Feed
on feathers and fur -Will take in some blood
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Phthiraptera

• Lice

Lice of Livestock (winter problem) -Cattle Biting
Louse -World-wide distribution -Attack all
ages of cattle -Head, neck, shoulders, and
rump -Irritate skin of animal
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Phthiraptera

• Lice

Lice of Cattle -Cattle Biting Louse -World-wide
distribution -Attack all ages of
cattle -Head, neck, shoulders, and
rump -Irritate skin of animal Control Prevent
an infestation (examine new cattle)
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Phthiraptera

• Lice

Lice of Cattle -Cattle Biting Louse -World-wide
distribution -Attack all ages of
cattle -Head, neck, shoulders, and
rump -Irritate skin of animal Control Prevent
an infestation (examine new cattle) Insecticides
Numerous pour-ons available, as well as
feed-throughs
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Phthiraptera

• Lice

Lice of Cattle -Longnosed Cattle
Louse -World-wide distribution -Deposit one
egg/day -Calves dairy stock -Dewlap
shoulders
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Phthiraptera

• Lice

Lice of Cattle -Longnosed Cattle
Louse -World-wide distribution -Deposit one
egg/day -Calves dairy stock -Dewlap
shoulders Control Not any different
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Phthiraptera

• Lice

Lice of Cattle -Cattle Biting Louse -Longnosed
Cattle Louse -Shortnosed Cattle Louse -Little
Blue Cattle Louse -Cattle Tail Louse
present during summer
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Hemiptera

• Bugs

-80,000 species (11 K in NA) -Aquatic
terrestrial -Hemimetabolic -Large
pronotum -Mouthparts originate at
bottom -Forwings ½ scleritized
Diseases?
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Siphonaptera

• Fleas

-3,200 species -Laterally flattened -Usually have
ability to jump -Diseases?