Seriously, that is the single most creative post I've ever read on any forum so far. I have no answers for you but thanks for the laugh.

I'm also trully sorry about your Koi whatever happened to it.

Creative?? Possibly but concerned is a better word. The loss of a 24 inch Koi is distressing to many ponders.

Montalvo, Wiki states in it's first paragraph on the Pipevine Swallowtail that the butterfly is absolutely poisonous due to the diet it had as a Caterpillar. I had no idea! Thanks for the warning even though I doubt I have any in this area. I wonder what other surprises Mother Nature has like this.

" The Pipevine Swallowtail (Battus philenor)[1][2] is a swallowtail butterfly found in North and Central America. The butterflies are black with iridescent blue hind wings. They are found in many different habitats, but are most commonly found in forests.[3] The black or red caterpillars feed on Aristolochia species, making them poisonous as both larvae and adults, while the adults feed on the nectar of a variety of flowers."

It is doubtful the large butterfly could manage to get inside the surrounding grid to get zapped. I remember being very concerned about a Luna Moth that clung to a Zapper all night and the next day. It flew away only after I unplugged the Zapper. Zappers don't usually attract much during the day and for mosquitoes you have to add on a bait packet.

Another thing to consider is that butterflies don't fly at night the way moths do. Or am I mistaken? I've never seen one or heard of one that does.

Thanks for the reply, sleepless. I could kick myself for tossing that caterpillar into the pond because when I picked it up, I said to myself, "Whoa, look at this guy...black with bright orange spines. This looks like the kind that try to keep animals from eating them because they're poisonous." And then I stupidly ignored my insight and tossed it into my pond.

I hadn't thought about the fact that the grid on the zapper would make it difficult, if not impossible, for the butterflies to get near the zapping grid. I'm feeling much relieved so I'm going to hang it up. We're leaving Sunday for an African safari (24 days) and while I have an automatic feeder, I'll feel more comfortable with the zapper as a back-up. The auto-feeder has malfunctioned in the past and that's a long time for my koi to go without food, especially right before winter sets in.

No bugzapper! They kill too many good/beneficial insects. Would your zapper just drop them into the water? Wouldn't they be burned? No offense, but I think its a really bad idea.

I was saying the bugzapper was creative (dead bug fish food maker.)
I thought the dead Koi was sad and I'm sorry he lost the fish no matter if it was the caterpillar or something else.

We have a friend with a pond stocked with trout and when it was really hot he hung an old large satellite receiver over the pond for some shade. Next thing we know he hung a bug zapper from it and when he turns it on the fish start jumping.

LOL! Does he have pictures?

We did one year at our farm pond.