I know of two reports here of cyclops attacking small larvae.
One from Paris:
"since i found out that cyclops were what killed my axolotls"
One from Chris:
"larvae seemed to start disappearing and I just found out that it was cyclops type animals eating them"
"Cyclops are predatory, and fishkeepers have accused them of attacking very young fish fry. It's possible that they could attack very young newt larvae. I have used them as food for newt larvae in the past without any problems- they are useful for larvae that are not big enough to eat Daphnia."
"Cyclops are nearly impossible to avoid in any tank, except one full of small newt larvae because they get eaten. All of my tanks have Cyclops in them. Most Cyclops species you'll encounter are harmless, and the ones that aren't are way too small to harm adult or juvenile newts."
"There are some species of copopods that can and will predate upon larval fish (both fresh water and marine). While keeping this in mind they still make wonderful food for many small newts and salamanders."
"I'm feeding my larvaes pond water which contains the micro organisms and I go out every now and then to catch some cyclops and daphnia." http://www.thekrib.com/Food/cyclops.html
In this link someone is accusing cyclops of attacking fish fry and of being almost as big as Daphnia in the UK.
Finally from what I have gathered from around the web cyclops are very small animals(max. 3mm), people seem to confuse bigger predatory copepods that attack fish fry and newt larvae with cyclops pretty often. However cyclops are omnivores that eat almost anything that they come across like algae, bacteria, dead organic matter etc.
So they probably can attack larvae but if there's other food items I presume they prefer them...
The best advise I have found are that cyclops(not to be confused with other copepods) aren't dangerous to larvae if fed in proper amounts i.e. do not feed huge amounts that will eradicate all food available and then have to go for the larvae: http://fins.actwin.com/live-foods/mo.../msg00016.html
I find it a little difficult to see why feeding cyclops to larvae should be considered a "don't do" even though one should keep an eye open and not add too much.
(Message edited by Jesper on November 08, 2004)