If we have to consider the pain of a lobster, then we have to consider the pain of its close cousins -- insects. Are you arguing that using a bug zapper is equivalent to the holocaust?
Yes, in my opinion we do in fact need to consider the existence of all biomass on earth, which includes the pain that any life experiences.
I would not say that a bug zapper is equivalent to the holocaust, but it is a tool that is often unnecessarily used. Killing bugs with a zapper is sometimes a symptom of a problem that can be prevented. I'm not a pest expert, but I do know that eliminating standing water in your yard will hinder mosquitos from breeding. There are other things that can be done to mitigate all pests. But alas, the bug zapper does have its role in areas where mosquitos are a serious problem.
This is about living in harmony with the planet we have inherited. It is irresponsible to callously maime and slay life just because we are going to eat it. If we are to take nourishment from life, then that life should be treated with respect.