Well, waterbugs,boatmen,backswimmers all have piercing mouthparts which hurt like a sting, but no true stingers live under water that I know of. Paul.

Thanks Paul. I will check out the info on them. Min

Btw, there are very few spiders in the US that would bite you. Most "spider bites" here are actually from mites, fleas, ticks, etc

:)

Giant water bugs, and water scorpions will also bite you if they think you are food. Use google images to find images of these. These are larger insects, 3-5 inches, so are likely to be seen before being handled, but they do like to hang out in thick algae and weeds to ambush food.

Hi Min! I wonder if it could have been a wasp that had come to get a drink of water out of the pond and went unnoticed as you scooped up the algae.

Hi Roselee - that is certainly a possibility altho I was looking at the small clump of algae as i lifted it and was stung/bitten so instantly that a wasp shouldn't have escaped my notice.

Also I have been stung by different critters before and this was an odd pain-ache-itch sting/bite that I havn't ever experienced. I couldn't ignore it for the first day or two and it was very very tiny! Quite a toxin! That's why I keep thinking, spider.

chuckr - I wonder how young and small those water bugs and scorpions can be and still bite? Thanks for the info.

I just posted about a Tarantula Hawk wasp so now I feel that my little whatever sting wasn't so bad, tho it did ache and itch for a long time. Min