Can you define the true abundance of the insect? I can make two traps. One trap the insect cannot see (wrong color, wrong pheromone, etc...). The other trap is repellant. I conclude that the first trap is the best one because it had a higher capture rate. If I knew the true abundance, I could figure out that both traps were bad, only one was worse than the other.

What is trap LOD? I place a trap in the field. There is 1 target insect per square mile. Does my trap catch the insect? I place another trap in the field, but there are now 500,000 insects per square meter. Does the trap catch reflect the difference in abundance?

Accuracy versus consistency: There is one insect per square meter, the trap attracts insects within a 10 meter radius, so the trap catches 314 insects. Same scenario, but the trap only captures 20% of the insects. So I always get 63 insects. Same scenario but the trap catches between 40 and 90% of the insects. I therefore get between 126 and 283 insects in each trap. If the trap is neither accurate nor consistent then it is adding random noise to my data and it will be hard to interpret the results.

What are my needs? I am running a quarantine operation to prevent an invasive insect from entering the safe zone. I consider everyone safe if there are fewer than 1 insect every 1,000 square kilometers.

You could try using many trapping methodologies with the idea that if you try enough of them they can't all be repellant. I like using an insect sweepnet as a sampling tool that is fairly independent of insect behavior (but labor intensive). I might also consider releasing 100,000 marked insects and then try to recapture them. You could then look at the total number recaptured, and look at the ratio of marked to unmarked individuals.