Gonotrophic cycles and behaviour rhythms Flashcards
How long does a blood meal take to be converted into eggs?
About 3 days
How is swarming behaviour controlled?
Circadian rhythms. Timing is species-dependent and segregation of timing may play a role in reproductive isolation within species complexes e.g. An gambiae stops swarming earlier than An coluzzi.
Strong peak of circadian activity in the evening.
What equipment is used to measure mosquito activity by sound?
Acoustic actograph
How can one artificially suppress circadian activity?
Continuous light –>phase resetting effect
How long do mosquitos swarm for before resting?
Max 2 hours
Why do mosquitos usually mate before blood feeding?
May be a change to host-seeking behaviours to get a blood meal to produce eggs. Reprogramming following taking up of the spermatozoa and sperm of the male
What is matrone? What are its effects on females?
A peptide produced by the male accessory glands (MAG). Reprograms females to behave as if they have mated even if they have not as they believe they are “inseminated”.
It causes the secretion of the ecdysone hormone by the ovaries.
What are the things which affect circadian activity?
- Blood feeding
- Ecdysone hormone
- Male accessory gland (hormone matrone)
- Moonlight (simulated) dim light (causes phase resetting)
What is mosquito activity relative to moonlight?
Activity concentrated in the early phase of the moon (in its first quarter) and flying throughout the night when the moon is full.
Describe the activity of A aegypti?
Males have a bimodal pattern of activity peaking in the morning and afternoon.
Why does blood-feeding and egg-laying of Aedes aegypti occur in a small range?
Have a short dispersal range, unlike An gambiae.
How long does it take for malaria parasites to mature in a mosquito?
About 10 days
Describe the activity of mosuqitos when infected with plasmodium.
- Downregulates activity early in infection (minimises mortality risk while developing, makes mosq less responsive to host)
- Sporoziotes developed- engages in more risk taking behaviour e.g. probing, more persistent blood feeding. also causes production of ASPARASE enzyme which causes blood to clot in proboscis so full bloodmeals are not taken, takes more blood meals
Describe the activity of mosquitos when infected with plasmodium.
- Downregulates activity early in infection (minimises mortality risk while developing, makes mosq less responsive to host)
- Sporoziotes developed- engages in more risk taking behaviour e.g. probing, more persistent blood feeding. also STOPS production of APYRASE enzyme which causes blood to clot in proboscis so full bloodmeals are not taken, takes more blood meals
Describe changes in activity of mosquitos when infected with filarial worms
-L3-more likely to feed than when infected with L1 or 2
