[vecter]

How quickly would the local population of mosquitos adapt to the MosquitoDunks, such that within a few generations, the only surviving ones would be the ones that are unaffected by the dunks? Or is that not a real concern?

[bee_rider]

I wonder…

I don’t know much biology, but is there a general principle where things that have a shorter reproductive cycle tend to “win” these sorts of arms races? I wonder if we will have to occasionally go out and find better copies of the bacteria, haha.

[throwup238]

The arms race might not even be realistically winnable for the mosquito. Most of the time when we talk about resistance it’s to a single molecule or evolutionary adaptation. That mosquitos have not developed a resistance after decades of heavy use (we’ve been using Bt as a pesticide since the 1920s and its the most used pesticide today) implies that the Bacillus thuringiensis used in the dunks/bits is attacking the larvae with multiple different mechanisms of action.

When that happens, natural selection almost always fails to develop a resistance because a resistant organism needs to have a defense against every mechanism of action at the same time. The probability of two beneficial mutations lining up perfectly to create that resistant organism are just extremely unlikely. That’s the basis for modern oncology, which uses combination therapy to prevent tumors from growing resistant to any one drug.

Edit: yep I was right. Against mosquito larvae, Bt produces multiple Cry toxins that bind to specific protein receptors in the microvilli of midgut epithelial cells and Cyt toxins that directly interact with membrane lipids [1]. It’s a triple whammy because there’s six major toxins (Cry4Aa, Cry4Ba, Cry11Aa, Cyt1Aa, Cry10Aa, and Cyt2Ba), Cyt1Aa creates more binding sites for the Cry toxins to attack the cell, and Cyt1Aa itself has two mechanisms of action, one of which disassembles the cell membrane, leading to cell death. That is an incredibly difficult evolutionary hole for an organism to dig itself out of.

[1] https://www.pnas.org/doi/10.1073/pnas.0505494102

[vecter]

I presume so. Here's a great example of it with bacteria: https://www.youtube.com/watch?v=bDa4-nSc7J8