Midterm 2

Question 1

Digeneana trematodes - common traits

Answer 1

spined tegument
anterior sucker
hermaphrodites/monoecious (usually)

FW fecal eggs –> miracidia –> DP to snail –> cercariae –> int host 2 –> metacercariae –> trophic def

Question 2

Digenean flukes - life cycle diffs (embryonation? int host 2? def?)

Answer 2

P.westermani - UE, crustacean, human
C. sinensis - UE, fish, human
F. hepatica - UE, plant, humans + livestock/animals
schistosoma - E’d, no int 2, human

schistosoma details - dioecious
- metacerc shed immunogenic tegument + tail
- migrate to heart/lungs to fed on RBC –> mature/sex in liver
- urine/fecal eggs

Question 3

Digenean flukes - symptoms + diagnosis method

Answer 3

Pw - diarrhea, fever, eosinophilia –> ELISA feces for eggs + detection of charcot leyden crystals
Cs - bile duct blockage –> inflammation + metaplasia + abdominal pain –> MRI for blockage
Fh - migrates to bile duct + liver –> abdom pain from enlarged liver + duct inflammation –> microscopy + ELISA for eggs

schistosoma - release of eggs = immunogenic –> formation of granuloma due to surrounding by macrophages
granuloma formation damages liver/spleen, intestinal (depending on species)
schistosomiasis diagnosed by microscopy + ELISA

Question 4

Specific schistosoma + where are the eggs laid + basic symptoms

Answer 4

S. mansoni - intestinal eggs, diarrhea
S. haematobium - intestinal eggs, kidney dmg + bladder cancer
S. japanicum - urinary eggs, katayama fever

Question 5

S. japonicum - How was it eradicated

Answer 5

• Farmers used oxen –> reservoirs –> convince to use horses instead
• Farming waterways = snail breeding grounds (recall snails = int hosts for trematodes) –> concrete dams to minimize/destroy snail breeding grounds

Question 6

hymenoptera overview

Answer 6

parasitic wasps
impact pest populations –> used by farmers as biocontrols (eg T. planipennisi)
2 wing sets + thin pedicel waist

Question 7

hymenoptera T. planipennisi

Answer 7

bicontrol for emerald ash borer
wasp lands on ash trees –> detects viubrations of ashr borer larvae underneath bark
ovipositor lays eggs –> larvae feed on ash borer larvae

therefore protects the ash trees

Question 8

hymenoptera cortesia congregate - life cycle

Answer 8

adult lays eggs inside tobacco hornworm caterpillar –> larvae feed on haemolymph
larvae emerge –> form cocoons on surface
pupate inside cocoons –> adult wasps emerge and caterpillar corpse left

Question 9

Cortesia congregate - how does it change hornworm behaviours

Answer 9

• disables molting signals –> prevents hornworm from pupating
• disabled feeding –> prevents consumption of cocoons
• aggression –> protect C.congregate larvae
• mutualistic virus disables hornworm immune system –> protect larvae
• venom to incapacitate hornworm –> allow injection of eggs

Question 10

SO Nematocera overview

Answer 10

blood sucker flies
1 wing set + filamentous antennae
eg sand flies, mosquitoes, black flies

Question 11

Nematocera - Sand flies

Answer 11

carry Leishmania
night feeders
control: day actvities only + fans (weak fliers, easily deterred)

Question 12

Nematocera - Mosquitoes

Answer 12

carry plasmodium (malaria) + lots of other disesases
eolongated mouth parts –> penetrate deep into skin
control: breed on stagnant water surface –> surfactants + agitation + destroy (eg tip over buckets)

Question 13

Nematocera - Black flies

Answer 13

transmit heartworms
day feeders
control: sprays/repellants. breed in all many water sources –> difficult to reasonably control

Question 14

SO Bradycera overview

Answer 14

Bite + licking blood flies
reduced antennae
eg Tse Tse, stable flies, bot flies

Question 15

Bradycera - Tse Tse fly

Answer 15

carries T.brucei
blue/black clothing attraction –> wear lighter colours
eggs laid in shaded vegetation soil –> clear land to destroy breeding grounds
blue/black insecticide nets

Question 16

Bradycera - Stable flies

Answer 16

problematic to dairy farms –> swarms cause mass blood leaching to livestock
eggs laid in manure –> control = good cleaning

Question 17

Bradycera - Bot flies

Answer 17

eggs laid on transport host flies –> land on mammal
body heat causes eggs to hatch –> larvae burrow into skin
larvae feed under skin –> fall onto ground –> molt –> mature

control by covering holes to suffocate –> tweezers to remove

Question 18

Bradycera common controls

Answer 18

insecticides/larvicides
sterile male release (eg screw worms)
change behavior to avoid contact

Question 19

Pthiraptera order

Answer 19

lice/louse –> ectoparasites + large claws
no wings, nymphs (incomplete metamorphasis)
dorsally flattened
body + pubic/crab + head lice

Question 20

Phiraptera - the 3 lice

Answer 20

body lice
- can survive on clothing –> move to skin for feeding
- exccess body lice = pediculosis (yeast infection of bites causes skin thickening)

head lice
- requires constant body heat –> cannot survive on clothing
- limited to head hair only

pubic/crab lice
- enlarged claws
- sexual transmission

Question 21

hemiptera order

Answer 21

ventrally flattened
bed bugs –> wingless
night feeders
incomplete metamorphasis (nymphs)

Question 22

checking for bed bugs

Answer 22

do not toss luggage on bed
check:
- under sheets
- bed seams
- headboard
- furniture directly next to bed

Question 23

phylum chelicerata overview

Answer 23

ticks/mites
- no body segmentation –> unlike arthropoda
- head + idiosoma (bulbous body)
- egg, larvae, nymph, adult –> hybrid metamorphasis

Question 24

ticks overview and life cycle

Answer 24

lack wings –> climb onto vegetation and brush against hosts
adult –> blood meal –> lay soil eggs
eggs hatch –> larvae hibernate #1
larvae find host –> grow –> fall off –> hibernate –> repeat a few times until reaching adult

Question 25

common tick symptoms

Answer 25

infestation = anemia
bites –> bacterial infections
biting base of skull may cause temporary paralysis
ripping tick off –> leave mouthparts in skin –> dermatosis skin inflammation

Question 26

ixodidae ticks

Answer 26

hard ticks
transmit lyme disease (25-50%)
48hr feeding times

lyme disease –> bullseye rash + nerve pain + mild paralysis –> prevent with constant checks for tick removal

Question 27

argasidae ticks

Answer 27

soft ticks
do not carry lyme disease
short feed times

Question 28

Aquatic parasites

Answer 28

Crustacean
- penillidae (cod worms)
- ergasilids (gill lice)
- caligids (sea lice)
Branchurians (fish lice)

Question 29

penillidae

Answer 29

aquatic parasite - cod worms
adult binds gills –> burrow into fish –> head extends into heart to feed on blood
not ecto or endo parasite -adults. Juvies are exclusively ectoparasitic

Question 30

ergasilids

Answer 30

aquatic parasite - gill lice
antennae binds gills –> lay eggs on gills
juveniles hatch –> swim and mature in water
only females feed on fish

Question 31

caligids

Answer 31

aquatic parasite - sea lice
use mouth to bite and latch to fish (anywhere on body)
eggs retained on female while bound to fish –> juveniles hatch
juvies swim to new host –> feed and mature

MARINE ONLY –> cannot tolerate FW –> infects salmon when they migrate

Question 32

branchurians

Answer 32

aquatic parasite - fish lice
Bite to adhere to fish
survives marine and FW
adults lay eggs on rocks/substrata –> direct metamorphasis –> juvies hatch ready to bind host –> mature