Let me try...
How about, grass, moose(moose eats grass), black fly(when moose dies it's eaten by fly), fish(fish can catch flies sometimes), and then Osprey(birds eat fish).
The second one... How about, grass, deer(deer eats grass), then wolf(eats deer), the mosquito(sucks wolf's blood), I don't know the dragon fly though
HOPE THAT HELPED SOMEWHAT :)
