josieskid said:
But, I'm catching adult fungus gnats on the yellow traps. What I have found some information on is that there is no correlation between damp soil and the proliferation of fungus gnats. They don't care about that - they'll eat your cactus roots too.
Can you tell me where you found information that there's no correlation between damp soil and fungus gnat proliferation? It's a general recommendation that managing moisture levels can influence their population, including this in an article by an entomologist who specializes in fungus gnats:
"Moisture management and sanitation are important in reducing problems with fungus gnats in greenhouse production systems. The use of well-drained growing media and not over-watering plants may avoid issues with soil-borne plant pathogenic fungi, thus diminishing the possibility of disease transmission by the larvae and adult. The accumulation of water and presence of algae may lead to abundant populations of fungus gnats and thus damage to greenhouse-grown crops"
https://www.mdpi.com/2075-4450...
If you read further down the article there's an interesting comment about Bounce dryer sheets!
There's also this: "Substrate Water-Holding Capacity
We noticed that some substrates in our trial held more water than others with consistent watering. The soil moisture of the organic mixes was generally higher than in the conventional mixes, perhaps due to the use of compost and fewer aggregates (such as perlite) in some of them. In general, substrates that held more water produced more fungus gnats (Figure 4); however, this was not a hard and fast correlation with every substrate. Our assumption is that wetter substrates encourage the growth of the microbes on which the larvae feed."
https://www.greenhousegrower.c...
