state_dict is basically a dict. So what you can do is define a mapping dict like:
mapping = {'feature.0.weight': 'conv1.weight', ......}
And load like this
state_dict = net.state_dict()
state_dict.update({mapping[k]: v for k,v in pretrained_state_dict.items()}) # Since you have new parameters, you have to update upon the current state_dict
net.load_state_dict(state_dict)