Phylum Arthropoda, Class Insecta, Order Siphonaptera (fleas) Flashcards
What are the general features of the order Siphonaptera?
Only adults are parasitic - other stages will be in the environment
Adults feed on blood
Mammals and birds are hosts
Fleas can transmit parasites, bacteria, viruses
Wingless
They are laterally compressed
Contain head, body, thorax
They contain one or more combs / ctenidia
- Genal ctenidia = ventral side of head
- Pronotal ctenidia = dorsal side of thorax
Mouthparts are well adapted for piercing and sucking
Thorax contains three legs, third pair is longer and is specialised for jumping
What is the general lifecycle of fleas?
Four stages:
Egg –> larva –> pupa –> adult
Holometabolous development - complete morphological change.
Eggs –> laid in environment or if laid on host, will fall into environment
Larvae –> maggot-like
The larvae will spin a cocoon and turn into a pupa. During this stage, has complete rework of the body.
Adults emerge from cocoons after a couple of weeks.
Under ideal conditions, the lifecycle may be completed in 3 weeks but can be prolonged up to 1 year. The adults will only emerge from the cocoons when they get stimulation that the host is around (vibrations, Co2, etc)
if they are not stimulated, will remain in the cocoon.
The adults move onto the host.
What is the most prominate feature of Genis Ctenocephalides?
Contain genal and pronotal ctenidia.
What is the general features of Ctenocephalides felis?
Prominant in 92% of dogs and 97% of cats
Most important ectoparasite of dogs and cats
Significance for humans –> can bite humans when pets are removed from the environment or the flea population is large.
Adults feed on blood, once on the host, initiate feeding in minutes.
The larvae feed on the adults faeces, each other and egg shells.
The adults are very good parents, they feed on high amounts of blood and the excess blood is excreted with the faeces. The larvae then feed on the faeces.
Contains setae
What is the lifecycle of Centocephalides felis?
Holometabolous development
egg–> larva –> pupa (within cocoon) –> adult
Females lay eggs within 36 hours after their first blood meal. Most eggs fall off the host within 8 hours, mainly accumulate where the pets sleep and rest. Eggs are pearly. Faeces from adults fall into environment –> food for larvae
Larvae develop at the base of carpet. Most larvae are found around were the pets rest or spend most of their time.
Pupae
- L3 spins a silk-like cocoon which turns into a pupa. Is sticky, best protected and is the most resistant life stage. They will not leave the cocoon unless they sense a host around (vibration, Co2) this causes issues for control.
Pre-emerged adults
- Is the waiting-stage, ideal for the survival during the absence of hosts
- Can emerge after 10 days up to 6 months
- Stimuli for rapid emergence is pressure and heat
Adults
- Permanent parasites, once adults move onto the host, will not leave unless forced too (licking, scratching). Will not transfer to another host
- Become infected from fleas within the environment.
What pathology can emerge from the infection of Ctenocephalides felis?
Flea Allergy Dermatitis –> skin condition
What is the general features of Echidnophaga gallinacea?
Infect birds mainly, also can infect dogs, cats, rabbits and humans.
Do not contain ctenidia (combs)
Angular head
Thorax is greatly reduced and dorsally narrow
Longer mouthparts
Not safe to pull off chickens as the mouhparts are so deep - cause major damage.
What is the lifecycle of Echidnophaga gallinacea?
Adults usually attach to the skin of the head, often in clusters of 100 or more.
Can also be found around the comb, wattles, etc.
The skin around the point of attachment may become ulcerated.
Stays attached on the skin of the host for many weeks.
Eggs dropped into the environment, eggs can also be laid within the ulcers –> forms into larva and drops into the environment.
What is the pathology of Echidnophaga gallinacea in humans?
Enter into the skin of the host and can cause severe reaction –> hosts can loose fingers and no longer walk, etc.
Females can increase in size over 100 times during feeding.
common in brazil.
