Exam 2: Biting gnats, mouthparts, horse & deer flies

Question 1

describe how biting gnats/midges eat

Answer 1

long, cutting mandibles - make a cut on the skin and a pool of blood will come up and they feed on the blood that wells up “pool feeders”

Question 2

what is culicoides hypersensitivity in horses and what is it caused by?

Answer 2

intense dermatitis; occurs in the late summer; crusty areas on underbelly and back where hundreds of gnats come and feed
Saliva that they inject when they feed is where dermatitis and sensitivity comes from

Question 3

chronic seasonal dermatitis in horses

Answer 3

severe itching, welts, crusting; tail and mane; ventral midline; during warmer months in temperate areas; pastured horses

Question 4

biting gnats breeding sites

Answer 4

wet, seepage areas

Question 5

most important infectious disease of white-tailed deer

Answer 5

epizootic hemorrhagic disease (EHD) virus or bluetounge (BTV) virus

Question 6

Bluetongue and Epizootic Hemorrhagic Disease viruses are transmitted by

Answer 6

Culicoides gnats - late summer to early fall

multiplies in gnats and mammals

Question 7

consequences to BTV and EHD

Answer 7

major obstacle moving ruminants to other countries because they don’t want BTV and EHD

Question 8

blue-tongue in sheep

Answer 8

exhibit symptoms of infection - become lame and listless; ulcers around mouth, nose and eyes
can be high mortality rate in some sheep breeds due to bacterial infection

Question 9

factors that contribute to BTV and EHD

Answer 9

drought, animal density

focus deer into smaller areas where they come in contact with gnats (near water); when infected they get more thirsty

Question 10

gnat management practices

Answer 10

breeding site reduction; grazing times and sites (reduce exposure); insecticide applications (animal protection); reduce stress (antibiotics); vaccines (for strains); fans

Question 11

what type of gnat is a day biter and only females are blood feeders

Answer 11

buffalo gnat, black flies

Question 12

black flies, buffalo gnats how do they transmit disease

Answer 12

mechanically

Question 13

mass come out in spring and have painful bites

Answer 13

black flies, buffalo gnats

Question 14

strong fliers

Answer 14

buffalo gnat, black flies

Question 15

buffalo gnat larvae require what type of environment

Answer 15

flowing water - riffles firm smooth substrates
filter organic debris, on rocks with fast flowing water which act together to oxygenate
6-9 instars
1 wk pupal stage
1 to multiple generations

Question 16

black fly attacks

Answer 16

eyes, ears, nose exposed skin
painful bite
anaphylactic shock
blood loss
pathogens
sometimes get bacterial infections from bites

Question 17

black fly management

Answer 17

access to shelter-barns, sheds, etc.

repellents - insecticides

Question 18

mouthparts of adults

Answer 18

chewing - primative
sucking
blotting
none

Question 19

chewers

Answer 19

grasshopper, biting lice, beetles, cockroaches

Question 20

piercing-sucking

Answer 20

mosquitoes, stable flies, horn flies, sucking lie, mites, ticks

Question 21

cutting/slashing

Answer 21

pool feeding horse and deer flies, black flies, biting gnats

Question 22

piercing sucking tend to have what? unlike the slashers

Answer 22

something to numb the pain

Question 23

stable fly - horn fly are what kind of feeders

Answer 23

blood feeders

have bayonet - like mouthpart pierces skin, sucks blood

Question 24

horse and deer flies are what kind of feeders

Answer 24

cutting/slashing - pool feeders

Question 25

horse and deer flies rely heavily on their sense of

Answer 25

sight

Question 26

sponging / blotting insects feed on what? how?

Answer 26

liquids - tears, mucous, - face fly | dissolves solids/blots up liquids - house fly

Question 27

suborder nematocera include

Answer 27

``` primitive flies - biting and non-biting mosquitoes black flies ceratopogonids (biting gnats) long antennae --> 8 segments, males fuzzy females blood feeders, males nectar larvae with distinct head, often filtering mouthparts larvae usually aquatic ```

Question 28

mosquito vs. biting gnats vs. black flies larvae

Answer 28

mosquitoes: always moving, standing water, filter feeder biting gnats: long and threadlike black flies: filter feeder/brush mouthparts, found in flowing water

Question 29

have spots on wings

Answer 29

biting gnats

Question 30

scales on wings

Answer 30

mosquitoes

Question 31

horse and deer flies are also known as

Answer 31

green heads

Question 32

horse and deer fly adults form

Answer 32

fewer antennal segments (4-8) | larval head withdrawn into 1st thoracic segment -aquatic, semi-aquatic - pond streams and banks

Question 33

horse and deer fly larvae feed on

Answer 33

worms, insects (they're predators)

Question 34

dark pattern on wings, more likely to attack people than a horse fly

Answer 34

deer fly

Question 35

black horse fly

Answer 35

1 in long blue black painful bite typically lay eggs on vegetation about moisture

Question 36

black horse fly life cycle

Answer 36

egg masses on vegetation over water pupate in drier soil dispersed sensitive environments

Question 37

female vs male horse and deer flies

Answer 37

females are blood feeders males are pollen and nectar feeders

Question 38

strong fliers - disperse 2 to 20 miles

Answer 38

horse flies deer flies

Question 39

horse and deer fly feeding patterns

Answer 39

slash skin/pool feeder 25-30 flies on animal over 6 hours b/c painful bite cant eat full meal at once increases their importance as a mechanical transmitter

Question 40

impact of horse and deer flies

Answer 40

reduced weight gain; nuisance/behavior; dermatitis; mechanical transmission of disease (amt of blood on mouthparts; interrupted feeding)

Question 41

anaplasmosis

Answer 41

destroys RBC, causes severe anemia cattle, sheep, goats, wild ruminants anything that carries blood -insects, ticks, needles, etc appears following stress - transport processing august - october (end of the time that insects are active) 4-6 week incubation period survivors are carriers

Question 42

arthropod spread vs human contamination of anaplasmosis

Answer 42

human contamination would be more cows all at once faster flies more gradual over time ad less cows at once

Question 43

equine infections anemia "swamp fever"

Answer 43

persistent viral disease - no vaccine 2 strains -equid reservoir transferred by blood

Question 44

equine infectious anemia prevention

Answer 44

reduce biting fly populations, 200 yd buffer between negative and untested horses coggins test-tests for EIA antibodies

Question 45

horse and deer fly feeding behavior

Answer 45

wait in shady areas for hosts to pass | calm sunny days

Question 46

most important sense for horse and deer flies

Answer 46

sight - shape, contrast, 3-d co2 also important movement of host

Question 47

horse and deer fly traps

Answer 47

big black beach ball type thing and they get directed up into cone mostly black "wings" give 3-D look hit palstic and fall in soapy water, attracted by warmth and shape

Question 48

tabanid catches on horse models

Answer 48

black- most by a lot brown - 2nd most white - a little zebra - nearly none

Question 49

tabanids do not respond strongly to

Answer 49

strips | thinner and more numerous stripes deter flies

Question 50

flies react to

Answer 50

polarized light | dark animals - strong reflection of polarized light

Question 51

deer and horse fly management

Answer 51

source reduction usually not practical because usually treating rivers/streams (sensitive areas you can't treat with insecticide animal protection/repellents selective grazing or confinement inhibition of food intake in arthropods-sulfakinins (produced when they get full to stop them from eating)