Try Amazon for the Spartan tubes
I have one of those as well. We love it, it works great. We've had it for a few years now and it did need a bulb replacement this year(came with a new bulb)
You could also try Spartan Mosquito tubes. We've used them for years and don't have issues with mosquitos in our yard. Follow the directions. Since the mosquitos are so bad, I would start with permethrin like @Wyorp Rock said then put the Spartan tubes up. Double whammy those suckers