So, I'm curious, how does this work, exactly? Because, to my reading, what you would do is basically "take up" a female moth for a mating season, as she would produce inviable offspring (so, basically, take her out of the gene pool, I think. I don't know how long moths live). Wouldn't you have to re-introduce the modified moths every season, as they self-eliminate from the gene pool?
The article doesn't shed a lot of light on the mechanism. i think your assumption is essentially correct, that if you flood an area with moths that produce sterile females, then the productivity of the area will decrease in the second generation, since conceivably, there's a maximum amount of carrying capacity for a given plot of land, and a sterile female takes up as much resources as a fecund one. They mention that the gene tends to be selected away in several generations, so yes, it sounds like this would be something that you would have to constantly maintain, unless you were able to get enough penetration that the population collapsed, an unlikely event, I'm sure.