It's true that inbreeding of a small population results in deleterious recessive traits becoming more readily apparent. However, this would still normally apply

It's true that inbreeding of a small population results in deleterious recessive traits becoming more readily apparent. However, this would still normally apply only to a small percentage of offspring. As such, I would not expect inbreeding to affect the viability of an insect species at all. If they can produce a viable first generation, the large majority of that generation can produce a viable second generation. Mammals might have a harder time with inbreeding because they produce few children, and as such any problems are less likely to be resolved through another line.