Lecture 20 4/23/24

Question 1

What are the general characteristics of insects?

Answer 1

-separate head, thorax, and abdomen
-six legs
-0-4 wings
-simple and/or compound eyes
-antennae
-mouthparts
-striated muscle
-chitinous exoskeleton shed periodically
-complete or incomplete metamorphosis
-most are free-living or ectoparasites

Question 2

What are the general characteristics of lice?

Answer 2

-compressed dorsoventrally
-wingless
-recurved claws for grasping hair/feathers
-small thorax w/ short, stout legs
-eggs laid one at a time
-nits are the eggs; resistant to treatment
-incomplete metamorphosis
-highly species specific

Question 3

What are the characteristics of Mallophaga lice?

Answer 3

-biting/chewing
-head wider than thorax
-hosts include birds and mammals

Question 4

What are the characteristics of Anoplura lice?

Answer 4

-sucking
-head more narrow than thorax
-hosts include mammals

Question 5

Where do all of the lice life stages occur?

Answer 5

on the host

Question 6

What are the characteristics of Anoplura infestation?

Answer 6

-important cause of anemia and hypoproteinemia
-able to treat w/ injectable systemic treatments
-efficient vectors of diseases such as Rickettsia prowazekii, Borrelia spp., and tularemia

Question 7

Which species of lice are seen in humans?

Answer 7

-head lice/Pediculus humanus capitis
-body lice/Pediculus humanus humanus
-pubic lice/Pthirus pubis

Question 8

Why is it important that human lice are not transmitted by animals?

Answer 8

-infected humans must have gotten it from another human
-human lice on animals indicate contact with an infected human

Question 9

What are the characteristics of Haematopinus suis?

Answer 9

-largest louse species
-found in folds of skin behind ears and between legs
-blood-sucking activity leads to discomfort and irritation

Question 10

Which species is the Anoplura species of the dog?

Answer 10

Linognathus setosus

Question 11

What are the characteristics of Linognathus vituli?

Answer 11

-long-nosed cattle louse
-Anoplura of cattle
-treated with ivermectin

Question 12

What are the characteristics of Trichodectes spp.?

Answer 12

-antennae stick out from head
-Mallophaga
-minor intermediate host of Dipylidium caninum

Question 13

What are the characteristics of Bovicola spp.?

Answer 13

-seen in livestock
-Mallophaga
-antennae stick out from head
-easily visible three-segment antennae
-cause irritation

Question 14

What are the characteristics of Bovicola bovis?

Answer 14

-irritation leads to self-barbering
-focal areas of alopecia
-can see nits in fur
-treat with pyrethrin dust

Question 15

What are the key factors of treating lice in livestock?

Answer 15

-treat ALL animals
-dose to appropriate weights
-read labels; some chemicals can be toxic, and some products should not be used in pregnant/lactating animals
-take appropriate environmental precautions
-observe withdrawal times
-retreat ALL treated animals 10-14 days after first treatment

Question 16

What are the general characteristics of fleas?

Answer 16

-complete metamorphosis
-laterally compressed
-wingless
-separate head, thorax, abdomen
-6 legs
-hind legs specialized for jumping
-adults are parasitic; feed on mammals and birds with piercing/sucking mouthparts
-juveniles feed on flea dirt

Question 17

Which fleas are of importance in dogs and cats?

Answer 17

-Ctenocephalides felis (dogs and cats, most common on both)
-Ctenocephalides canis (dogs)

Question 18

What is the life cycle of C. felis fleas?

Answer 18

-eggs appear 2 days after male and female fleas arrive
-eggs accumulate where host rests
-L1 hatch around day 4
-larvae feed on adult flea feces
-L3 larvae spin cocoons and metamorphose into adults 2 weeks later
-after 3-4 weeks, adults emerge from cocoons
-adults can survive up to 2 months without a host
-once host is found, adults will remain on host and repeatedly feed and reproduce; rarely leaves host on its own

Question 19

What are the clinical signs of fleas?

Answer 19

-flea allergy dermatitis
-anemia

Question 20

Which pathogens are vectored by fleas?

Answer 20

-Dipylidium caninum
-Acanthocheilenema (imposter heartworm)
-plague
-Bartonella

Question 21

How are fleas diagnosed?

Answer 21

-visible fleas/flea comb
-flea dirt

Question 22

How are fleas treated?

Answer 22

-vacuuming
-remove bedding
-treatment of carpet
-treatment of all pets

Question 23

Why must adulticide, IGR, and environmental control all be used when treating fleas?

Answer 23

in order to control all stages of the life cycle on the host and in the environment

Question 24

What are the characteristics of hemiptera?

Answer 24

-true bugs
-two pairs of wings
-triangular shield between the wing bases
-four-segmented antennae
-three-segmented beak

Question 25

What are the characteristics of hemipteran life cycle?

Answer 25

-development by simple metamorphosis
-can feed on plants, other insects, or suck blood
-predacious reduviids inflict painful bites

Question 26

What are the characteristics of Reduviidae?

Answer 26

-wings and characteristic three-segmented beak
-Triatominae subfamily is parasitic and feeds on blood of vertebrates
-hide in crevices by day; attack sleeping hosts at night
-incomplete metamorphosis
-transmit Chagas’ disease in the feces

Question 27

What are the characteristics of Cimicidae/bed bugs?

Answer 27

-oval, dorsoventrally flattened bodies
-vestigial wings
-three-segmented beaks
-disagreeable odor
-simple metamorphosis
-nocturnal, secretive bloodsucking parasites
-hide in crevices during day and attack sleeping hosts at night
-can endure starvation for several months
-not confirmed to spread disease

Question 28

What are the characteristics of bed bug behavior?

Answer 28

-shelter in cracks in walls
-prefer rough substrate
-have eyes and will react negatively to light

Question 29

How do bed bugs feed?

Answer 29

-anchor to skin with claws of the legs
-feed from a blood vessel
-completely engorge in 3-10 minutes