Parasitic arthropods & parasitoids Flashcards
Arthropoda:
leg number
in insects?
in arachnids?
6 for insects
8 for arachnids
Arthropods make up what % of all the multicellular organisms
Arthropods are about 80% of all the multicellular organisms.
Group of extensive ecological heterogeneity.
Most successful taxonomic group
on the planet Earth.
Classes of arthropods relevant to this course.
Insecta
Arachnida
Mites and ticks belong to what subclass?
Acarines
Mosquitoes
Flies
Sandflies
belong to what order
Diptera
bedbugs belong to what order
hemiptera
mallophaga/chewing lice and lice belong to what order
phthiraptera
fleas belong to what order
siphonaptera
insect and arachnid main differences in morphology
insects have a 3 segmented thorax
arachnids have head, thorax and abdo fused together
insects can have wings (arachnids nah)
insects can pierce, suck or chew; arachnids can only bite or suck
arachnid 4 stages in a life cycle:
egg
larva (3 pairs of legs, no respiratory organs)
nymph (4 pairs of legs, respiratory openings)
adult
Parasitic arthropods
* Feed on:
– blood
– dead skin cells
– hair
– Feathers
- Skin damage
- Secondary infections
Parasitic flies / true flies of order Diptera (two-winged) include:
subsist off bloodsucking and bodily secretions.
– Mosquitoes (Culicidae)
– Biting midges (Ceratopogonidae)
– Flies (Muscidae)
– Botflies (Oestridae)
– Black flies (Simuliidae)
– Horseflies, tabanids (Tabanidae)
Parasitic true flies (Diptera)
* cause energy loss to livestock through:
– flying
– landing
– blood loss via biting
– reduced feeding and feed intake
– stress
- capable of transmitting a variety of pathogens, thereby leading to significant economic loss.
Life cycle of a dipteran fly includes
eggs
larvae
pupae
adults
Describe mallophaga/chewing lice (Phthiraptera)
- Mallophaga (chewing lice) is a group of obligatory ectoparasites mainly of birds and to a lesser extent (only 12%) of mammals.
- They are small (0.5-11 mm), wingless and flat, often with no eyes.
- They become adults at the age of 3-4 weeks.
- Mallophaga mouth parts are biting type.
- They feed (chew) on the surface layer of the host’s skin (epidermis), hair and feathers, less often on blood.
Describe Lice (Phthiraptera)
- Lice (Anoplura) live predominantly on mammals and their mouth parts are of the sucking type, lice feed on blood.
- Inside the wound, they secrete saliva, which prevents blood from clotting but causes uncomfortable itching for the host.
- Lice are small (up to 6 mm) wingless insects that have developed specially constructed gripping legs to hold on the hair.
- Eggs are attached to the hair. Larvae also feed on blood, becoming adult in 20-25 days.
- The largest of the lice living in Estonia, 4–5 mm, is the hog louse (Haematopinus suis). (pictured)
Describe Fleas (Siphonaptera)
- Mouth parts are biting type, directed downwards.
- All fleas are ectoparasites of mammals and birds.
- Adults feed on the host’s blood, biting the skin. The flattened body on the sides of the fleas facilitates movement between
the host’s hairs or feathers. - Fleas specialize in a specific species of bird or animal. If necessary, they also feed on the blood of other animals.
- For example, humans are bitten by a cat flea (Ctenocephalides felis) and a dog flea (C. canis).
Estonian tick species.
Proven 2 hard bodied tick species that are known vectors for infections:
– Sheep tick / castor bean tick (Ixodes ricinus)
– Taiga tick (Ixodes persulcatus)
More studies needed! probably more species
Describe the brown dogtick.
ruskea koirapunkki
(Rhipicephalus sanguineus)
- Came from Northern Africa
- Arrived in Finland in1970-ies
- Everywhere in the country, but only lives indoors! (crazy, right?)
- Active around the year
Itch mite in latin
Sarcoptes scabiei
Parasitoid is …
an organism, usually an insect, that lives on
or in an host organism during some period of its development and eventually kills its host.
A Parasitoid lays it’s eggs into host’ body
where the larvae hatch and eat live tissues of the host.
The host is often specifically an insect. Insects using parasitoid strategy mostly belong to the orders of Hymenoptera and Diptera.
The difference between parasite and parasitoid is that
a parasite is never interested in the
death of its’ host. Parasites gain from the host in order to live on and distribute parasites further.
The development and foraging of parasitoids always ends the life of the host.
Why should a veterinarian care about parasitoids?
Impact on Animal Health
Understanding Parasite Ecology: Parasitoids are integral components of ecosystems and can influence parasite dynamics and transmission patterns.
Parasite Control Strategies: Parasitoids can be used as biological control agents to manage pest populations in animal environments.
One Health Perspective: Parasitoids are part of complex ecological systems thus, in disease ecology, veterinarians can contribute to holistic approaches to disease prevention and control that benefit both animal and human health.
Explain Honey bees (Apis mellifera) and parasitoid Apocephalus borealis (Diptera)
Apocephalus borealis is a species of parasitic fly. A. borealis flies typically lay their eggs in the abdomens of foraging honey bees.
Once the eggs hatch, the fly larvae develop inside the bee, eventually causing the death of the host.
This parasitic behavior can have significant impacts on honey bee colonies, especially when infestations are severe.
Describe Biological control of farm filth flies by using parasitoids.
- Production animal farms use commercial parasitoids to control filth flies. Parasitoids feed on filth flies’ eggs and larvae so they never mature and reproduce further.
- Examples of parasitoids used in farms for biological control:
– mite (Macrocheles muscaedomesticae)
– Coleoptera (Carcinops pumilio)
– Dipteran (Hydrotaea aenescens)
– Parasites of diptera (Muscidifurax raptor, Spalangia cameroni, S. endius)
