Is this itinerary doable by public transportation?
 

I am thinking of adding Sicily to our Europe trip, but I do not want to rent a car in Italy, if possible. Is the following itinerary doable by public transportation (bus or train).

After flying into Palermo I would like to visit:
Monreale
Erice
Agrigento
Valley of the Temples
Taormina
Siracusa
Plaza Armerina
Fly out of Palermo or Catania

How many days would we need to see the above?

Any itinerary is doable by public transportation if you have enough time (which you failed to specify).

Our time is unlimited as we are retired and have not as yet booked airfare. I was thinking I would like to spend a week to 10 days on the ground in Sicily. I guess my question is whether the itinerary is doable in a fairly efficient way(ie-without needing many bus connections getting from one place to another).

Basically you cover 2/3rd of the perimeter of the Island, avoiding the northern part.
We did the same and did it in about 10 days - with a car.

No idea of the time it can take with trains, sorry.
Just wanting to say that a car is confortable and driving in Sicily is NOT complicated. However, if you have reasons not to take a car, good for me, but don't be afraid.

No problem at all. See my TR Reflection on Revisiting Sicily. The only place I didn't get to was Piazza Armerina and this is certainly doable if you have plenty of time.

Monreale is a short bus-ride from the centre of Palermo. For Erice you need to be in Trapani from where it is 30 mins by bus. Get to Trapani by bus 2 hours from Palermo
Agrigento is a bus or train ride from Palermo and the Valley of the Temples a 5 min bus ride from the station.
You can get to Taormina by bus or train from Palermo. Bus is quicker.
Siracusa is an hour by bus from Catania airport.

Suggest you use 2 bases, one Palermo and one Siracusa. Probably 2 weeks is minimum time. Otherwise concentrate on one end of the island or the other.

Thanks for your input. It is very much appreciated.

There are several good trip reports on the board about visiting Sicily by public transportation -- please seek them out, as I'm sure you'll find the information quite helpful! I'm pretty sure one was by GAC and another by Marija.

And check Rome2Rio and the Rough Guide for great public transportation information.

Hope that helps!

I was also going to suggest rome2rio.com as I find it invaluable.