Ask Mr. Smarty Plants

From a previous Mr. Smarty Plants answer:

If all the leaves are gone, we would suspect deer.  We don't know what part of San Marcos you are in but this area of Central Texas has high populations of deer.  Styphnolobium affine (Eve's necklace) is listed as moderately deer resistant but in this time of drought the deer are very likely to eat whatever is available.  You can try some of the deer repellents (chemical or mechanical) that are available at nurseries or you can fence the area to keep the deer out of your garden.  Some people put black plastic netting over or use it to make a barrier around the plants to keep the deer from eating them.  It would depend on how tall your plant is or how big your flower bed is as to whether this method would be a feasible method for your situation.  The Rhode Island Department of Environmental Management has an excellent article, "Reducing Deer Damage to Your Yard and Garden", with descriptions of several methods of control, including homemade repellents.

Unfortunately, if a plant is being relentlessly attacked, sometiimes you must make the choice not to plant it, or to replant in a part of your garden that can be protected. By the way, the flowers and seeds of this plant are poisonous, but it looks like the deer know that.