Vectors Flashcards
Name 4 common categories of vectors
mosquitos, flies, cockroaches, rodents
Most mosquitos (are/are not) harmless. Only the (female/male) is a vector of diseases.
most are not harmless
only females are vectors
Why does the female mosquito need to take in blood of warm blooded animals?
In order to mature her eggs
What attracts a mosquito to a warm blooded animal?
The carbon dioxide
A mosquito inoculates the skin with an _________________ prior to taking blood. What purpose does it serve?
anticoagulant chemical
It desensitizes the area prior to the bite
A mosquito bite is considered an ________________
inoculation
List the names and times of the 4 stages of a mosquito life cycle
- egg laying (typically on stagnant water)
- larval stage 2-3 days eggs hatch, larvae are in water and come up to breath
- Pupa stage 4-10 days still in water, not as active
- Adult stage 48 hours then they sit on the water to let wings dry for 6 hours
The entire mosquito life cycle from egg laying to adult takes approximately _____________ days
11 to 16 days
Anopheles sp. (malaria) characteristics
adults sit at 45 degrees.
larvae don’t have physical breathing tube
Culex sp. (encephalitis) characteristics
adults sit at 45 angle.
larvae have long breathing tubes
Aedes sp. (yellow/dengue fever) characteristics
larvae have short breathing tube
What tool can inspector use for a larval survey
a mosquito dipper
What is a dry ice trap
device that uses CO2 to attract mosquitos and trap them for study
What is the purpose of using petroleum based oils (Tossits) on surfaces of ponds and lakes
it blocks mosquito larvae breathing tubes causing them to drown.
petroleum can’t be used in California so now some detergents are used instead.
Name two natural enemies of mosquitos that can be used to biologically control mosquitos. describe how they control mosquitos
Gambusia affinis (mosquito fish) a minnow species that can consume up to 200 larvae a day.
dragon fly - dragon fly larvae eat mosquito larvae, and adult dragon flies eat adult mosquitos
When mosquito larvae control has failed what are ways to control adult mosquitos?
spraying insecticides
using screens/bed nets
protective clothing
repellents such as DEET, vitamin B 12, garlic
Name 6 diseases transmitted by mosquitos
west nile virus malaria yellow fever dengue fever encephalitis filariasis
Name 18 diseases a fly can cause
onchoceriasis bacillary dysentery hepatitis round worms tapeworm ameobiasis (cycsts) typhoid fever amoebic dysentery fly larvae myiasis whipworm shigella African sleeping sickness paratyphoid fever infantile diarrhea pinworms hookworm salmonella e-coli
describe the body characteristics of a fly
lower abdomen, thorax with single pair of wings, head with large compound eyes, mouth and antennae. three pairs of legs
larvae of flies is commonly known as ___________
maggots
What are two categories of fly species
biting variety
non biting variety
Name 6 types of biting flies
horse fly deer fly stable flesh fly black fly sand fly
Non-biting flies are also known as _____________ flies
Name some common non-biting flies
domestic or synanthropic flies
house fly green bottle fly bronze bottle fly cluster fly blow fly screwworm fly filter fly moth fly lesser house fly
Describe the 4 stages of the fly life cycle
- eggs - sometimes carried with the adult until ready to hatch. need moisture, warmth and nutrients
- larvae - aka maggots, active white worms
- pupa - not mobile, matures in soil
- adult fly
Name 4 things required for a fly to survive
Warm temperature
Moisture
Food Source
Soil
What is the food source of a fly
feces, decaying organic matter, food etc. they are not picky
How does a fly eat?
it regurgitates onto the food source and then consumes it. flies require moist food.
How can a fly cross contaminate?
e.g. would be feeding on dog feces then landing on your food and regurgitating diseases picked up from the dog feces
What time of day are flies active? Where do they typically rest?
active during the day.
Rest on edges and protected areas from wind
the average fly can travel at ____ mph
4 mph
A house fly can travel up to _____ miles in a 24 hour period
6 miles
Most flies usually remain in a vicinity of about _____ square miles
1 square mile
What is the life span of a fly?
ranges greatly.
2-4 weeks
can survive 6 months of hibernation
flies are inactive below ____F and killed below ____F and above ____F
45
32
112F
Phototropism refers to how flies are attracted to _______
light
house fly is scientifically known as ___________ and prefers to lay eggs in ______
musca domestica
feces
Features of the cluster fly/face fly
musca autumalis
cooler climates - attics
fly around faces of cattle
can cause pink eye
lesser house fly
fannia cunicularis
smaller than house fly
rarely lands
Stable Fly
Stomoxys calcitrans sits with rear end up in the air warm areas of the gulf coast vicious biters breeds on horse manure
False stable fly
muscina stabulans
slightly large than house fly
attracted to human foods
Dump Fly
shiny black flies
common in cities near garbage
Tse-tse fly
tropical, Africa
brown colored
African sleeping sickness
Flesh Fly
sarcophagi occidua
red tip on abdomen
larvae used in civil war to debride wounds
bottle fly and blowfly
blowfly is green metallic
bottle fly is blue metallic
breed on dead animal flesh
black blow fly
black shiny thorax with blue/green abdomen
abundant in early spring
Black Fly
second in line to mosquitos for their blood sucking abilities
eggs laid on flowing water
swarm around human eyes, nose, mouth
bites become itchy
Deer Fly
chrysops discalis
also rival mosquitos as they are vicious biters
atlantic coast and salt water/marsh lands
Fruit Fly
drosphillidae
breed on decaying fruit
Mediterranean are very destructive
attracted to fruit liquor bottles and can end up dead inside
_______ are one of the filthiest creatures in the world
flies
The easiest way to eliminate flies is to eliminate their ________
potential breeding environments
pick up feces and control garbage and decaying matter
If proper sanitation fails then fly larvae control can be accomplished by the following
spreading manure to dry
using pesticides
traps
sugar water bowls with oil drops
What are three pesticide spraying types for flies
residual sprays
space sprays/aerosol bombs/space foggers - all for enclosed spaces)
aerial spraying (done by plane)
alternatives to spraying pesticides for flies include
fly baits fly cords resin strips screening air curtains electrocution (zaps) uv light sterile male flies (expensive) biological control (insects, bacteria, fungi)
What can bacillus thuringensis be used for?
fly control
What are three devices use to trap flies for surveying
baited fly trap - set on ground, cheap method
fly cones - similar to fly trap
fly grill - most commonly used - gives faster assessment of population. the grill is placed over natural attractants
___________________ is considered one of the most intelligent in the insect world
the cockroach
cockroaches belong to what family of species?
Blattidae
Do cockroaches bite?
no
Different species of cockroaches can be identified based on markings on their ________________
pronotum (body shell)
Name 4 species of cockroaches which can plague human residences and food establishments
german
brown banded
oriental
american
german cockroach
blatella germanica
can come from potato sacks, onion bags, cardboard
most common
1/2-3/4 inch
pale to light brown with two longitudinal stripes
warm moist dark environments
7-10 months lifespan
brown banded cockroach
supella longipalpa
1/2 ‘’ long
light brown color w/ one dark band
aka radio or TV roach
like warm dry environments
males can fly
3-7 months lifespan
What are ootheca?
eggs of cockroaches
oriental cockroach
blatta orientalis resemble a beetle outdoors, moist dark water areas cannot climb shiny black 1-2 '' long 4-5 month lifespand
American cockroach
periplaneta Americana largest of domestic cockroaches 3-4 '' long red/brown may have dark spots common in sewers they can fly
cockroaches are active at (day/night/both)
night time
What is pyrethrum used for?
can be used to bring cockroaches out of hiding
What does cockroach defecation look like and where can it be found?
small brown specks like ground pepper.
can stain walls
often in cabin doors and other crevices
What does cockroach odor smell like?
can smell slightly sweet and musty
Do cockroaches carry diseases?
no but they can mechanically transfer contamination since they tend to move around from dirty areas to clean areas.
which cockroach species are more likely to cause an infestation inside?
german and brown banded
unless there is a plumbing leak then maybe the American or oriental
What is the best method of cockroach extermination
tenting the premises with fumigation gas
it’s expensive though and required temporary relocation of tenants
when spraying an apartment complex for cockroaches which direction should spray be applied?
from the outside to the inside
after spraying pesticides for cockroaches how long do tenants usually need to stay out of the premises?
4-6 hours
WHy are resprayings for cockroaches required 3-4 weeks after the intial spray?
because the eggs from the prior infestation could hatch
What are the two common tenting gases used for cockroaches?
methylbromide
vikane
What are 4 methods that consumers can use to treat cockroach infestations
home use pest control sprays
roach motel insect traps
combat insecticide baits
glue traps
How does a roach motel work?
it’s a cardboard box with an odor attractant. an adhesive strip traps the roach
How do combat insecticide baits work for cockroaches
black disposable plastic slotted with odor attractant and poisonous bait the cockroach does not die immediately so where you find dead roaches will be where the infestation is
How can boric acid powder be used against cockroaches
they will groom themselves and then be poisoned.
the powder can be applied to crevices and other areas
What is an illegal cockroach treatment
insecticide chalk from china
List 8 rodent-borne diseases
rat bite fever murine typhus leptospirosis plague salmonellosis rickettsial pox trichinosis lymphocytic choriomeningitis
describe the common victims of rat bats
sleeping children with food debris near the mouth. poor socio-economic environments
Name 3 domesticated rodents of concern to environmental health
Norway rat
roof rat
house mouse
Norway rat
rattus norvegicus adults 1 - 1.5 feet in length about 1 lb thick tails shorter than body length stocky body grayish red, brown, black small eyes female litters of up to 8 rats as many as 7 times a year "sewer rat" prefer subground environments do not like to climb vicious
roof rat
rattus rattus aka "laboratory rat" smaller and less vicious slender body and tail is 1/3 longer than body 1.5 ft lgnth fur varies, brown, gray, black (light on underside) large eyes and ears litters of 6-8 up to 6 times a year very good climber lives in warmer climates, sourthern US and subtropical live in higher elevations pickier eaters
house mouse
mus musculas smallest 2.5 to 3.5 inches long tails are 2-4 inches longer than body weight under an oz gray brown fur pointy nose and large eyes under houses, between walls, cabbinets can survive dry environments they like cereal grains
describe the senses and physical abilities of rodens
eyes - poor sight, color blind
excellent hearing, sense of smell and taste
great balance and agility, can jump up to 2 feet
great swimmers
they run along walls because their hairs have a strong sense of touch
they are weary of strange things which prevent traps from working sometimes
rodent dropping identification
Norway rat - large up to .75 inches long shaped like a capsule
roof rat - .5’’ droppings with banana shaped ends
house mouse - .25’’ droppings are very small and pointy rod shaped
How can you tell fresh rodent droppings from old ones
fresh will be soft, moist, dark and shiny
grey or crumbly can be a few days or many weeks old
how is tracking powder used in rodent identification
can be laid along walls and looked at by flash light to see if an infestation is present
rubmarks
a dirty and oil mark left on wood beams often where rats infest
Why do rodents gnaw?
because their front incisors grow 4-6 inches a year so they have to grind them down
results in wood being destroyed
electrical wires etc.
which rodent burrows?
Norway rat
What is a concrete L used for?
under housing and buildings to prevent Norway rats from burrowing into homes
how can a home be rodent proofed?
vents should be screened
pipes should be no greater than 1/4 ‘’
bushes and trees should be cut back from building
make sure doors are flush
What is the purpose behind ectoparasite control in rodents?
because rodents are an excellent vector to other organisms such as fleas.
powdered pesticides such as sevin, malathion and diazinon should be used.
Name the 4 routes of absorption for pesticides
stomach poisons (baits) contact poisons (dusts) fumigant poisons (inhaled) dessicants (dries out the pest)
a highly toxic substance would have an LD50 of \_\_\_\_\_\_\_ mg/kg toxic moderately toxic slightly toxic non toxic
5-50 highly 50-500 500-1000 1000-5000 5000 and up non toxic
pyrethrum
botanical
LD50 of 1500
chrysanthemums
What is allethrin
a synthesized form of pyrethrum with a higher toxicity level
what is an example of pesticides with chlorinated hydrocarbons
DDT and lindane
lindane
low doses are used for head lice
ddt
dichlorodiphenyltrichloroethane
BANNED!
LD50 of 500
very effective pesticide but remains stable for too long
bad for birds and other species in the environment because DDT does not break down
Aldrin
LD50 of 60
soil poison for termites
Chlordane
worked well on crawling insects but studies showed it vaporized and harmed people
Methoxychlor
LD50 of 5000
flea, flies, moths
relatively non toxic
can be used around dairys
organophosphaste -carbamates
extremely toxic affects CNS
Name 6 anticoagulants used as rodenticides
prival warfarin fumarin diphacinone chlorophacinone PMP
how do anticoagulants work as rodenticides (bait)
intake causes internal bleeding
however some rodents are resisting bait with anticoagulants
Name 10 toxic poisons - only applied by license pest control
red squill 1080 1081 ANTU nor-bromide strychnine zinc phosphide - garlic smelling gray powder) vacor organophosphates and carbamates - CNS paris green (mainly arsenic)
What are vermin
noxious or objectionable insects or animals that pose a human health risk, damage or contaminate food or property or create annoyance. common e.g. include flies, cockroaches, rats and mice
the most common cockroach found in the food establishment is ____________
german cockroach
rats typically stay within ______ ft from their nests while mice stay within ______ ft from theirs
rats 150 ft
mice 30 ft
