Maggots in pea seed

I would appreciate any advice on this.
My early peas are coming along nicely, notwithstanding attention from pigeons, but I sowed a different variety more recently with very patchy results. The few that came through soon keeled over. Upon investigation I managed to find some remnants of the original seed in the ground and they were infested with small white maggots. Do you think that this could be due to infected seed. I wouldn`t think any local insects would have found the pea seed before it emerged in such a short time?

Pete