Arthropods

Question 1

What are the characteristics of Class Insecta?

Answer 1

Have a head with mouthparts, a thorax, and abdomen

Question 2

What are the characteristics of the the Order Diptera?

Answer 2

Have one pair of wings. Those that are ectoparasites serve as vectors for many pathogens and intermediate hosts for parasites.

Question 3

What is the difference between facultative myiasis and obligatory myiasis?

Answer 3

In facultative myiasis, flies use contaminated wounds to deposit eggs instead of garbage, feces, or carrion. They do not need to use tissue.

In obligatory myiasis, the fly larvae must develop in living tissue, such as organs, uncontaminated wounds, or other soft tissue.

Question 4

What are the characteristics of Anopheline mosquitoes?

Answer 4

Eggs- single eggs with floats

Larva- lay parallel to water surface, no air tube

Pupa- short air tube

Adults- rest at an angle to the host

Question 5

What are the characteristics of Culicine mosquitoes?

Answer 5

Eggs- single eggs on dry surface or rafts on water surface

Larva- at angle to water surface, short air tube

Pupa- variable or long/slender air tube

Adults- rest parallel to host

Question 6

For what pathogen are Anopheline mosquitoes vectors?

Answer 6

Plasmodium spp.

Question 7

For what pathogens are Culicine mosquitoes vectors?

Answer 7

Yellow fever, Dengue fever, and West Nile Encephalitis

Question 8

In what environment would you find larvae from the Family Tabanidae? What is the common name for members of this family?

Answer 8

Aquatic environment

Horse and deer flies

Question 9

Horse and deer flies serve as intermediate hosts for which parasites?

Answer 9

Trypanosoma theileri and *Elaeophora schneideri *

Question 10

Horse and deer flies serve as vectors for which pathogens?

Answer 10

Anaplasma spp., anthrax, equine infectious anemia

Question 11

What is the common name of Stomoxys calcitrans?

Answer 11

The stable fly

Question 12

What are the hosts of Stomoxys calcitrans?

Answer 12

Large domestic animals, dogs, humans

Question 13

Stomoxys calcitrans is a mechanical vector for which pathogens?

Answer 13

Various bacteria, equine infectious anemia, Habronema muscae, Trypanosoma evansi

Question 14

What are the characteristics of lice?

Answer 14

Small, wingless, dorsoventrally flattened body with crab-like legs

Have simple metamorphosis

Permanent ectoparasite, stenoxenous

Question 15

To which order do chewing lice belong? How can you distinguish them from sucking lice?

Answer 15

Order Mallophaga

Head is wider than the body

Question 16

To which order do sucking lice belong? How can you distinguish them from chewing lice?

Answer 16

Order Anoplura

Head narrower than body

Question 17

What are the hosts of lice in the order Mallophaga?

Answer 17

Various species infect either birds or mammals

Question 18

What are the hosts of lice in the order Anoplura?

Answer 18

Various species infect mammals only

Question 19

What is the common name given to organisms within the Order Siphonaptera? What are their characteristics?

Answer 19

Fleas

Laterally compressed, may have genal or pronotal combs

Complete metamorphosis?

Question 20

What are some problems caused by siphonapterosis (flea infestation)?

Answer 20

Irritation and restlessness

Anemia, flea allergy dermatitis

Fleas serve as vectors for plague and tularemia; intermediate hosts for Dipylidium caninum, Hymenolepis nana, and Dipetalonema reconditum

Question 21

How can one microscopically determine if a flea is male or female?

Answer 21

Presence of a spermatheca used to hold sperm in females

Question 22

What is the common name of members of the Order Acarina? What are their characteristics?

Answer 22

All stages feed on blood

Have simple metamorphosis

Question 23

Why can a tick’s life cycle take anywhere from six weeks to three years to complete?

Answer 23

Tick life cycles may require one, two, or three hosts.

Question 24

What are the two methods for disease transmission in ticks?

Answer 24

Transstadial- pathogen is in the larval or nymph stage and remains through molts

Transovarial- adult ticks transfer pathogen to eggs

Question 25

What is tick paralysis?

Answer 25

An ascending, flaccid paralysis caused by a neurotoxin in tick saliva- the toxin disrupts synapses in the spinal cord

Question 27

What is the basic body plan of ticks?

Answer 27

Capitulum- head with mouthparts consisting of a hypostome and palps

Idiosoma- fused cephalothorax and abdomen

May have a scutum that partially or completely covers idiosoma and festoons at the edge of idiosoma.

Question 28

What is the common name of organisms in the Family Argasidae? What are their characteristics?

Answer 28

Soft ticks

Look like puffy raisins

Do not engorge or have visible mouthparts

Question 29

What is the common name of organisms in the Family Ixodidae? What are their characteristics?

Answer 29

Hard ticks

Permanent ectoparasites, engorge, have visible mouthparts

Question 30

What is the common name of Rhipichephalus sanguineus?

Answer 30

Brown dog tick

Question 31

What type of life cycle does Rhipicephalus sanguineus have? What are the hosts it uses?

Answer 31

Three host tick, mainly uses dogs for all three stages

Question 32

Rhipicephalus sanguineus serves as a vector for which pathogens?

Answer 32

Hepatazoon canis, Babesia canis, Ehrlichia canis