General Arthropod introduction, mosquitoes, black flies

Question 1

Define Apolysis

Answer 1

A process which the old cuticle undergoes detachment from the epidermal layer to allow for a new layer of cuticle to be formed

Question 2

What is the importance of neurotransmitters in arthropods

Answer 2

Neurotransmitters in arthropods are Glutamate-gated chloride channels

This allows us to use macrocyclic lactones to attack and cause paralysis to them

Question 3

What is the important Ez which is released into the hemolymph in arthropods that is important in the initiation of molting?

Answer 3

Ecdysone

Ecdysone release in hemolymph –> conversion to 20-hydroxyecdysone –> causing cells of the epidermis to proceed with initiation of molting

Question 4

What process divides the life of the individual insect into instars as part of insect growth?

Answer 4

Ecdysis

Question 5

What do you call the metamorphsis of Egg-Larva-Nymph-Adult where juvenile instars look and act like smaller versions of the adult

Answer 5

Hemimetabolous (incomplete metamorphosis)

Question 6

What do you call the metamorphsis cycle of Egg-Larva-Pupa-Adult. Where juvenile instars are larvae and restructuring to adult form takes place during the pupil stage?

Answer 6

Holometabolous (complete metamorphosis

Question 7

The amount of what hormone within a arthropods system determines the form of the new cuticle?

Answer 7

Juvenile hormone (JH)

*JH prevents metamorphosis but will not interfere with molting

However, if prolonged the larva will not be able to survive and will lead to eventual death of the arthropod

Question 8

The _________ in the species Nematocera (long-horned flies) are ONLY ones responsible for feeding on blood?

Answer 8

Females

Question 9

1. Where are mosquitoes found?
2. What is the name of the mouth part of the mosquito?

Answer 9

1. Every habitat and climate zone
2. The proboscis
3. * Mouth parts within the proboscis contain a piercing stylet (the maxilla and andible contain scissors on them which causes the hole)

Question 10

In mosquitoes what is the job of the labium?

Answer 10

To select a suitable location for the proboscis to be inserted

Question 11

Where are all mosquitoe eggs layed?

Answer 11

In or near expected future water areas

*all larvae are aquatic

Question 12

How many instars or molts do mosquito larva go through

Answer 12

4

Question 13

What is mosquito larval growth dependent upon?

Answer 13

• Temperature
• Presence of food (bacteria, yeast, protozoa)

Question 14

1. The Culex sp. mosquito lays its eggs where?
2. Aedes sp. and ochlerotatus sp.?
3. Anopheles?

Answer 14

1. Eggs laid in rafts on the water
2. Eggs laid in small depressions on dry ground suspected of accumulating water
3. Eggs laid individually, bubble of air trapped by the frill keeps the egg floating

Question 15

Label the subfamilys of the given larval eggs in the photo

Answer 15

1. Anopheles
2. Adedes
3. Culex

Question 16

Each mosquito species has a preference for what three items

Answer 16

• Feeing times
• Blood source
• Water specifications for breeding and egg laying

Question 17

Define what a bridge vector is

Answer 17

the concept of a new vector (new mosquito) or the current vectors behavior changes (from a lack of food, etc.) and it feeding off a host it usually does not feed from.

*This causes disease transfer

Question 18

T or F

Some mosquitos sp. or individuals are better at transmitting a particular pathogen than others

Answer 18

True

Mosquitos availability as a vector is dependent on a large number of factors such as: climate, geography, species, even things such as health status and age of individuals

Question 19

List five possible diseases mosquitos can be a vector for

Answer 19

• Dirofilaria immitis
• Wucheereria bancrofti
• Plasmodium
• West Nile Virus
• Eastern Equine Encephalitis virus
• Western Equine Encephalitis virus

Question 20

In Eastern Equine Encephalitis (EEE) what mosquito keeps the disease in cycle, what species is the dz maintained in, and what is the bridge vector

Answer 20

• Culiseta mosquito keeps it in cycle
• Virus is maintained in birds
• Bridge vector is Culex sp. and Aedes sp.

Question 21

In Western Equine Encephalitis (WEE) what mosquito keeps the disease in cycle, what species is the dz maintained in, and what is the bridge vector

Answer 21

• Unknown
• Birds are the species it is maintained in
• Culex sp. mosquito is the bridge vector

Question 22

In West Nile Virus (WNV) what mosquito keeps the disease in cycle, what species is the dz maintained in, and what is the bridge vector

Answer 22

• Culex sp. mosquito
• Migratory birds maintain WNV
• Culex sp. mosquito is also the bridge vector

Question 23

What does one use to control mosquito populations?

Answer 23

Spraying adulticide

Spraying repellents and mechanical protection

Use of environmental controls: draining or filling breeding grounds

Question 24

T or F

Insecticide resistance in mosquitos is becoming a growing problem

Answer 24

True

Elevated esterases via gene amplification is being selected for –> resistance to organophosphates

Question 25

1. North American mosquitos are perfectly capable of transmitting what major diseases? 2. Why havent they however?

Answer 25

1. Malaria, dengue, and yellow fever 2. The standard of living in the US has resulted in decrease exposure

Question 26

1. Where are black flies, buffalow gnats found? 2. What is the major unique factor of these flies

Answer 26

1. Found worldwide 2. **They must breed in highly oxygenated water** **\*Remember b/c black flies, buffalo gnats are part of the nematocera family ONLY the females feed on blood**

Question 27

Describe other morphological and general features of black flies, buffalo gnats

Answer 27

* Vicious biters * Strong fliers * **Have a characteristic humped thorax** * Eggs are laid near water

Question 28

What is the life cycle of black flies, buffalo gnats

Answer 28

larva hatch and cling to stones (at bottom of the stream)--\> pupate --\> when adult is ready to emerge the **pupa will fill with gas** **and float bobs to the surface in the buble of gas** --\> they will float on surface to catch their breathe then readily fly away

Question 29

What is significant disease which we worry about when talking about black flies, buffalo gnats

Answer 29

We are worried about heavy swarming leading to allergic responses to the bite and **anaphylaxis**

Question 30

What diseases are black flies, buffalo gnats a vector for?

Answer 30

* Onchocerca* * **River blindness** * Onchocerca gutterosa* (in cattle) Viruses - **Vesicular stomatitis virus** *Leucocytozoon*