Tweening separate enemies defined in the same function

[Jubawub]

I have a function for my enemies (which in this game are bees)

Bees = function(index, game, x, y){
      this.bee = game.add.sprite(x,y,'bee');
      this.bee.anchor.setTo(0.5,0.5);
      this.bee.name = index.toString();
      game.physics.enable(this.bee,Phaser.Physics.ARCADE);
      this.bee.body.allowGravity = 0;
      this.bee.body.immovable = true;
      this.bee.body.collideWorldBounds = true;

      this.beeTween = game.add.tween(this.bee).to({
        y: this.bee.y + 1
      },500,'Linear',true,0,-1,true);

and to add them into the game I have 

Game.World1.prototype = {
      create:function(game){

        //other code.....

        enemy1 =  new Bees(0,game,240,40);
        enemy2 = new Bees(0,game,312,140);

  },

However, once I place these enemies into the game, I have no idea how to make them move independently.

For example:

enemy1 =  new Bees(0,game,240,40);

this.enemy1Tween = game.add.tween(this.enemy1).to({
        x: this.enemy1.x - 40
      },4000,'Linear',true,0,-1,true);

Gives the error "Cannot read property 'x' of undefined" 

x: this.enemy1.x - 40

How can I make each enemy move independently?

Or even better, how can I go about making each enemy move along different length platforms without falling off?

Thank you.

[scheffgames]

The Bees function does not have an x property. The bee property inside the Bees function does have an x property. So write this instead:

game.add.tween(this.enemy1.bee)