Mystery objects

Can anyone suggest what these are, please?  They're stuck to the house wall, and are about 1 cm from top to bottom of the group.  

I have discovered that they are probably the cocoons of the parasitic wasp Cotesia glomerata, "that lays eggs inside the body of the large white caterpillar. The larvae consume the caterpillar from the inside out, but avoid vital organs so the caterpillar can continue to grow. The larvae then spin yellow cocoons and emerge from the caterpillar."