Steve/Joe, from your description, it sounds like the anode rod is part of the drain plug. On my drain plug it's just a plastic drain plug, and there's no anode. Most of my trips will be a couple days in length, perhaps another longer 2 week trip out of the year. When stored at home I could easily drain the tank. So I'm not sure if it's worth putting in a anode rod if it's harder to get in and out to drain. Right now I have the plug out but it's a good idea to screen it against insects as you suggest Joe.
That plastic plug you have is just that..... a plug to replace the anode rod. If you only use it for say two days at a time and then drain it you could get by with that plastic plug (a week or more put the anode back in in my opinion)..... or you could get the petcock kind like i have and drain it after each use but at the end of the year take it out and put the screen in....... I learned a little trick from this forum a few years back that i use at the end of the year and that is to put a 18" piece of all cotton clothsline rope into the hot water tank and let it hang outside the open door and all the water on the bottom will "wick" out in a few days...... there are many ways to do things but this works for me.