Yes, this is a klepto. Indeed these are a klepto couple!
And another new species to me.
Say hello to Argyrodes species yet unconfirmed. She is above and he is below. And yes they are kleptos, or to be more precise kleptoparasites.
That is to say they live on other spiders webs and steal their meals when they aren't looking. I found these outlaws (or spongers, its a political call) living on the periphery of the web of a very large Garden Spider around the side of the house. I've convinced Mrs.B that this is sufficiently out of the way they she is NOT going to walk through the web and so successfully stood advocate for the Argiopes. Now while they may be parasites they certainly seem to me to live a very edgy existence. They skitter about the edge of her web which is now well over 2 feet across and as very small and nimble as they are I several times watched her feel their presence and turn that way. But being as she is literally thousands of times their mass I guess they get away with it as seeming ghosts. They are likely too small for prey themselves, there would be more calories expended in the chase and feeding than she could hope to get out of the meal. Kind of diet snacks at best.
Meanwhile these two sneak around the fringes of her huge web taking the prey that are like themselve too small for her to bother with. In fact they probably perform a useful function in keeping the web clear of all those scruffy little gnats and mosquitoes that would otherwise clutter it up without any nutritional value to the owner/builder.
Hopefully later today I can update with a species on these. They are either A. nephilae or A. elevatus. Which ever they turn out to be the common name is, appropriately, the Dewdrop spider