I don't remember the name or year or studio, but I'll give all the info I know.
The first one started off with lower class individuals at the DMV in I think New York, the main characters were random strangers who started talking to each other and noticed that others at the DMV weren't coming back out into the lobby, and then the main character got called back and went through a decontamination shower before going back to what looked like a human meat grinder, he survived and escaped, one of the other characters had a mail truck they escaped to and got away in. The main villain was a white woman, seductive 20s maybe. The larvae barely fit down people's throats and people were killed for food or turned bug, the bugs have taken over the police, politicians, etc. The main characters can't trust anyone and are limited by their low class status. Main character was a white guy, but the others were diverse.
In the sequel or 3rd movie (can't remember) the cold open starts with a flashback of astronauts being taken over by the bugs. One survives, a young white guy who isn't sure if he's a bug now or not, he tells the main characters that if they kill the queen, all the bugs die. They don't trust him, but they do the plan. They end up burning up the entire nest while the astronaut gets a larvae down his throat, they use a grenade in the nest and the nest is in a sewer/the subway station. The main characters barely make it out and in the end of the 3rd movie one larvae is showed to be still alive.
I think the trilogy was made by Sci-fi, and I found the full set in a Walmart $5 bin in probably 2012, so it wasn't a big hit. Please help me find the name of it, I loved the movies.