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!