Some of the information presented here is sourced - with permission - from High End TFs. Unfortunately eBay won't allow me to link you directly to this fine site, so you'll have to use your imagination (Google) to find it. Many thanks to MightGaine for his help!
In 2005 a company called Zhong Jin in China started manufacturing counterfeit G1 Transformers. These often appeared on eBay with ambiguous descriptions, like "China Reissues" or "KO Reissues", obscuring the fact that they were unlicensed counterfeits. Since then, a slew of counterfeit G1 toys have been released, and a second company, Kidi Toys, started making them as well. Recent copyright and tradermark enforcement attempts by Hasbro seem to have begun to force the counterfeiters to decrease their activity.
Two Ways to Spot a Counterfeit Insecticon
1) Box Colour
Nice and easy this one - the original Decepticon boxes were a cool blue-purple colour, the purple used on the modern counterfeits contains much more red and less blue in the mix, creating a red-violet shade. See below:
2) The Sunburst
Compare the yellow sunbursts in the pictures above. Notice anything? The original is a paler yellow with an aura around it, where as the counterfeit is a richer, brighter yellow ending abruptly with no surrounding aura.
Although I've only used images of Kickback, the differences are the same with all three Insecticons. To the best of my knowledge these are the only differences on the box. I don't know how well the figures compare to the originals, but if or when I find out the guide will be updated accordingly.