It's frass, the excrement of insect larvae. If you cut the pods open, you'd find little white grubs eating the developing seeds. It may yet be possible to save some of the seeds if you bore the holes open a bit (with the tip of a sharp knife or something similar) and spray insecticide into the pod. There are a lot of holes, though, each one indicates another grub, so it may be too late. What does the other side of the pod look like? Pods are divided into three chambers. I can tell from the picture that two of the chambers have grubs, but you might be able to save the seeds in the third chamber if they haven't gotten in there yet.
