Aedes albopictus Wolbachia Suppression: Ecological Dynamics

Okay, here’s a breakdown of the experimental methods described in the provided text, organized for clarity. I’ll cover the two main experiments (mating choice⁢ and mating latency) and the field monitoring of w*Pip infection.

* Goal: To determine if *GUA females show a preference for HC or GUA males.
* Setup:

* ‍ Mosquitoes (350-360 per cage) ⁢were allowed to mate for 24 hours. This high density was used to avoid density-dependent mating effects.
* ⁢ Males were removed after mating.
* Females were blood-fed 3 ‍days later using mice.
* ⁣ Blood-fed females were individually housed for egg-laying.
* Eggs ⁣were hatched after 10 days.
* Key Principle: GUA females‍ mated⁢ with⁣ HC males produce unviable eggs, while GUA females mated with GUA males produce viable eggs (this was validated in control ⁢crosses).
* ⁤ Data Collection: ⁣ The number of females producing viable vs. unviable eggs was counted.
* ‍ Analysis: A Female Mating Choice Index (FMCI) was calculated using the following formulas:
* FMCI to HC ⁢males = (N / R) / (Y + N / R)
* FMCI to GUA males = Y / (Y + N / R)
* Where:
‍ * N* = Number of *GUA females producing unviable eggs.
⁤ * Y* = number of *GUA females producing viable eggs.
* R* = Release ratio of *GUA male vs. HC ⁤ male.

2. Mating Latency Experiment (Assessing Strength of Preference)

* Goal: To assess the strength of female mating preference by measuring how long it takes a male to successfully mate with a female. The hypothesis is that females less interested in a male will take longer for a male to⁣ achieve a ‍stable mating pair.
* Setup:

* ⁤5 virgin males (1-2 days old) were ⁤placed in a 30cm x 30cm x 30cm cage with 10% sucrose water.
* 24 hours later, 1 virgin female (1-2 days old) was introduced.
* The time it took for a male ⁢to‍ seize the female and form a stable mating pair (resting on the cage surface) was recorded.
* Mating‍ Groups Tested:

* szGUA female x HC male
* szGUA female x xhGUA male
‍* xhGUA female x HC male
* ‍ Replication: The experiment was repeated ⁤10 times for each⁤ mating group.

3.Field Monitoring of⁤ w*Pip Infection

* Goal: To monitor the frequency of *wPip infection in mosquito populations in the field.
* Locations: Shazai Island and Dadaosha Island.
* Methods:

⁢ ‍* Larval Sampling (Shazai Island 2018-2020): Approximately 95 ovitraps were used, positioned as in a previous study [reference 21]. Egg-positive ovitraps ⁢were collected weekly and analyzed for w*pip.
* Larval Sampling (Dadaosha Island 2019): Larval samples ⁢were collected from ovitraps via PCR assays to determine if population replacement had occurred (release activity ⁢stopped in 2017).
* Adult Sampling (Shazai Island 2020): Female adults were collected using⁢ human-landing catch methods (3 independent activities) and tested for *wPip infection. Landing locations were‍ consistent with previous studies.

Let me know if you’d like any part of this explained in more detail, or if‍ you have other questions about the methods!