Ladybug larvae eating plants?

[Fig3825]

Okay, so everything I've read has always told me ladybugs are beneficial insects. Yesterday, I found some leaf damage and flipped the leaf to find what I would swear was a ladybug larvae eating my leaves! Is this possible? Whatever it was, I killed.

The damage was composed of some of the softer leaf underside being excavated - but not totally through the leaf except in a few locations. Imagine the underside of the leaf being excavated by a tiny excavator and the excavation fully penetrated the leaf to the top side in only a few locations.

From memory, it looked almost exactly like this:
[img]https://www.californiagardens.com/images/Asian-Ladybug-Larvae.jpg[/img]

There are two other possibilities, one is that I've misidentified the pest and the second is that if it was a ladybug larvae, it was eating whatever had made the holes - but I saw no evidence of a second pest.

Is there another pest that looks very similar to ladybug larvae?

[applestar]

What plant was it on?

[Fig3825]

Cucumber.

I'll take a picture of the damage done and will upload this evening. There's a good chance that where there's one, there may be many, and if so, I'll get a snap of the pest also. I didn't see any more and I've been diligent about inspecting daily and using a spray can to rinse the bugs off the leaves that I see. No more pesticides for me - I'm just smashing them or jetting them off with the water bottle.

[!potatoes!]

many beetle larvae look generally like that...could easily be mis-identified (not impugning your skills, but speaking as someone whop studied insects for years)...get a pic, and we'll figure it out.

[gixxerific]

That sounds weird to me but even if they were I would let them. They would do more good than harm after the mature.