25. Arthropods (mites) Flashcards
how many legs do the larvae of mites have?
6
how many legs do the nymphs and adults of mites have?
8
how do the leg numbers compare in lice, fleas, bugs and flies vs. mites?
insects - lice, fleas, bugs and flies remain with 6 legs throughout their life
do mites have wings?
no
what are the mites affecting humans?
- clover mites
- itch mites
- rodent mites
- bird mites
- chiggers
- house dust mites
- scabies mites
what is the genus of clover mites?
Bryobia
what are the characteristics of Bryobia spp.?
- This mite does not bite or cause health‐related problems.
- Clover mites can be red, green or brown.
- If smashed when they crawl over carpets, the mites leave a red stain.
- They have front legs that are about twice as long as their other legs.
what is the genus of itch mites?
Pyemotes
what are the characteristics of Pyemotes spp.?
- These mites prey upon insects.
- Humans are bitten when they come in contact with straw, hay, grasses, leaves, seeds or similar materials harboring the mites.
- The mites cannot be seen and the bites are not felt, but leave itchy red marks that can resemble a skin rash.
- The mites cannot live on humans, do not survive indoors, and are not known to transmit disease.
what are the genera of rodent mites?
- Liponyssoides sanguineus
- Laelaps echinina
when would a rodent mite bite people?
when their hosts die
what is the preference of the house mite in terms of host blood?
The house mouse mite (Liponyssoides saguineus) prefers to suck the blood of mice, but also will bite rats and people, often causing a rash around the bite
what temperature do rodent mice prefer?
warm places, pipes and furnaces, where rats live
what is the feeding habit of the spiny rat mite?
feeds on rats at night and hides by day in cracks and crevices around rat nests and resting places
what is the scientific name of the spiny rat mite?
Laelaps echinida
is the rat mite painful?
yes, it can cause skin irritation and itching
what are the bird mites?
- Ornithonyssus spp.,
- Dermanyssus gallinae,
- Cheyletiella spp
when do bird mites bite people?
when their hosts abandon their nest
which mites infest chickens? what do they primarily infest?
The northern fowl mite (Ornithonyssus sylviarum) and chicken mite (Dermanyssus gallinae) primarily infest chickens, but also pigeons, starlings and sparrows
how long can the northern foul mite survive off its host?
not more than a month
how long can the chicken mite survive off its host? what is its life style?
the chicken mite hides in cracks and crevices near bird nests during the day and feeds by night
which mites infect both birds and mammals?
Cheyletiella
what do Cheyletiella cause?
They can cause a mange‐like condition in pets, and itching in people who handle infested pets
do Cheyletiella mites remain long on humans
no
what is the scientific name for the chiggers?
Eutrombicula
which stages of chiggers prey on insects?
the nymph and adult stages
what does the six-legged larval stage usually feed on?
usually feeds on rodents or ground-dwelling birds, but will bite people if available
what color are chigger larvae?
red to yellow and appear as scarcely visible specks
do chiggers suck blood?
no but they cut into the skin and feed for several days on the skin; the bite becomes inflamed, hardens and itches
where are chiggers typically found?
in rural, less distributed areas and spend most of their lives in cracks in the soil
what is the scientific name for house dust mites?
Dermatophagoides
what is the cause of indoor allergies?
dust mites and their feces becoming airborn
what are the forms of allergic disease that house dust mites cause?
several forms of allergic diseases, including hay fever, asthma and eczema and are known to aggravate atopic dermatitis
what does the mite’s gut contain?
potent digestive enzymes that are expelled in their feces and are major inducers of allergic reactions such as wheezing
the mite’s exoskeleton can also contribute to _________.
allergic reactions
do house dust mites live on people?
no but they hitch hike on clothing
what do house dust mites feed on?
organic detritus such as flakes of shed skin that fall from people and animals, and flourish in the stable environment of dwellings
what harbours more dust mites, upholstered furniture (pillows, matresses) or carpets?
furniture
are the European and American house dust mites different species?
yes, but not confined to their names countries
what is the scientific name of scapies mites?
Sarcoptes scabiei
do scabies motes infest mammals? humans?
yes, humans included
how do most human infections with scabies mites arise?
person-to-person contact
what do scabies mites cause in dogs?
mange
what do scabies mites feed on?
believed to feed on skin and secretions
what is the path of infestation of the scabies mites?
The mite transmitted by contact burrows into the skin on the webbing side of fingers, later spreading to the wrists, elbows and the rest of the body
what happens sometimes in individuals have not been exposed to scabies?
the infestation may go unoticed for more than a month, then severe irritation and itching develops, especially at night
where does the life cycle of scabies mites take place? how long is it?
all 10-17 days spent on the host
without a host, do scabies mites survive?
only a few days
what is different for scabies mites?
scabies mites burrow and produce tunnels one centimeter or more in length just below the surface of the skin, in which they lay eggs
what happens if larvae escape the tunnels?
they wonder on the skin and start new burrows and mature to continue the cycle
what are the 4 stages in the Sarcoptes scabiei life cycle?
- egg
- larva
- nymph
- adult
what is the varroa mite?
the varroa mite is a tiny external parasite which attaches itself to the surfaces of honey beed and feeds on the haemolymph (blood)
what is the appearance of the varroa mite?
reddish brown and has a crab-like shape
what are the known hosts of the varroa mite?
Western or European honey bee, and the Asian or Oriental honey bee
where do the adult female Varroamites lay their eggs?
in the brood cells of honey bee hives
what do the Varroa mites feed on?
the bee larvae and pupae
what does Varroa feeding result in?
deformation of the wings and bodies of bees when they develop and emerge as adult bees
what happens to the bee populations as a result of feeding by the Varroa mites?
there is a decline in populations which ultimately reduces pollination necessary for the production of tropical fruits and vegetables
what are the various ways in which the Varroa mite can spread to other areas?
- By hitchhiking on infested honey bees and contacting uninfested bees.
- By honey bees from stronger uninfested hives “robbing” honey from weaker mite‐infested hives.
- By hitchhiking on other flower‐visiting insects.
- By the movement of infested managed hives or recently used beekeeping equipment to other areas.
which is the first mite to mature? (sex)
the male
