UFO in Duke II's Intro and Name of Duke 3D's Aliens

[Flying Techbot]

After announcing Duke's abduction in the intro to Duke Nukem II, the news reporter announces another story of interest:

In other news, there's a four-mile wide UFO floating over Los Angeles.

Since the Rigelatins never had the opportunity to invade Earth (after Duke destroyed their cities and usurped their spacecraft), is it possible that the UFO mentioned in Duke II's intro belonged to the alien race which appears in Duke Nukem 3D? Since Duke 3D was hinted at the end of the game, and that Los Angeles was invaded during the events of the third game, it seems likely that the UFO was a foreshadowing to what would befall the city during Duke's absence.

On another topic, what is the name of the alien race from Duke Nukem 3D anyway? They're only referred to as Aliens, but since Duke's previous foes had names such as Techbots and Rigelatins, I would think that the third threat was at least deserving of a name. All I know is they're primarily reptilian, with aspects of Alien's aliens, who are sometimes cephalopod-like (Octobrain) and swine-like. They also humanoidish, more so than the Rigelatins (with exceptions to the Blue Guard and Skeletons). The Protector Drones and the Queen seem directly inspired by H.R. Giger's aliens. Their most distinguishable difference from the Rigelatins, of course, is their obsession with human women for entertainment and breeding purposes.

Why did this alien race appear right after the Rigelatins abducted Duke? Were they the Rigelatins' allies or enemies? Could it be that their appearance was not monitored by the Rigelatins? How come Dr. Proton and the Rigelatins never thought of stealing chicks for evil purposes before? Lastly, why did this new alien race decide to invade Shrapnel City, the exact location where Dr. Proton's first secret base was located?

Out of the three antagonistic forces, the nameless aliens of Duke 3D are still rather mysterious.

[Sang]

I've heard some people refer to the aliens from Duke3D as the Cycloids (because of the Cycloid Emperor... Emperor of the Cycloids )