Vectors Flashcards
General mosquito life cycle
- Eggs laid in water
- Larvae - feeds and moults (lasts 10 days - 12 months!)
- Pupae - undergoes metamorphosis
- Adult mosquito
How to differentiate male and female mosquitoes
Males have plumose antennae (long hairs)
What is a vector species complex
A species complex is a group of closely related species that are morphologically similar or indistinguishable by microscopy. They are important because they may have different host preferences, resting behaviour (indoor/outdoor) feeding behaviours and
breeding habitat requirements.
Why is insecticide based control difficult in house flies?
- Huge range of potential habitats makes covering all these logistically difficult.
- feeding sites may be very distant from breeding sites.
- Multiple emergences of insecticide resistance mechanisms, to different classes of insecticides.
- High reproductive rate and fast life cyclemeans that rebound of population is very fast.
What facilitated the movement of Aedes Egypti out of Africa?
Human movement
- slave trade
- trading vessels
- suez canal
What is the role of climate change in vector born diseases
- affect vector population distribution and density
- increases life span / survival - increases probability that parasite can complete life cycle/ mosquito can bite twice.
- increase in reservoir hosts
- social and environmental drivers (housing, density, human behaviours)
Vector control of Aedes
Source reduction - very difficult as larval sites are millions of induvidual containers. Need community engagement - local removal of containers, cover and treat (larviciding) domestic water sources.
Fogging - used during outbreaks. No residual effects - repeat treatments required once new eggs hatch.
Insecticide residual spraying - has more long-lasting effect in homes
Insect growth regulator - pyriproxyfen - a synthetic version of mosquito hormone - prevent development of larvae into pupae. Safe to humans. May be spread around on the bodies of mosquitos themselves
Genetically modified male release - sterile males or dominant lethal gene (very expensive)
Gene drive - spread of genes that stop virus transmission
Use of Wolbachia - used to drive refractory genes into populations
What does hemimetabolous mean?
No pupal stage - direct from larvae to adult
Sandfly species and location
Phlebotomous - Old world
Lutzomiya- New world