Ebola cannot survive in insects. The only way an insect could transmit is if it landed on someone with Ebola, picked up some on its feet, and landed on an open cut on someone else.
Or landed on their food or drink.
One of the things I remember about Africa was all the flies. They were everywhere. Clouds of them. If there are that many ebola victims walking around in Monrovia there are bound to be puddles of this or that contaminated body fluid lying about. Likely covered with flies of some sort. That then fly off to the market and walk on the veg and fruit there. And buzz around people and walk on them...etc.
Walking, flying fomites!