It's on the title. I'm using the latest version of ad astra in 1.19.2 with forge.
The flies drop a large amount of maggots when on the moon (I haven't tested on other planets) generate a large amount of smoke when dying.

I have the same problem with Beyond Earth! ( similiar mod or even exactly like Ad Astra )
I tried use fly_spawns.json to disable fly spawn at moon

{
  "biomes": [
    [
      {
        "type": "BIOME_TAG",
        "negate": true,
        "value": "minecraft:is_end"
      },
      {
        "type": "BIOME_TAG",
        "negate": true,
        "value": "minecraft:is_nether"
      },
      {
        "type": "BIOME_TAG",
        "negate": true,
        "value": "minecraft:is_ocean"
      },
      {
        "type": "REGISTRY_NAME",
        "negate": true,
        "value": "beyond_earth:moon_desert"     <------    
      },

But no matter which combination with negate, biome tag etc i used - fly keep spawning!
Pls fix that!

@RejectFrontendEmbraceBackend I did the same as you, and flies really stopped spawning on the moon. It looks like you are changing the wrong config