Osmia cocoons are indeed "torpedo"-shaped as someone stated. The nipple is the last stages of silk thread that the larva exuded to finish off its cocoon so that is the head end. This is critical in having it oriented to the way out but actually cocoons should not be placed within the condo but instead in a separate container nearby or underneath the condo. Leave a small 5/16" hold in this container for the bees to escape from. The little light brown blobs is meconium, the adult bee's first poop and this will be at the outlet of the container showing evidence of them having left and flown away.
Incidently, the mud layer laid down within each cell by the female, has been "masoned" into position by her face which she has tubercles on the sides used in this process (how they're i.d.'d in fact), and the interior of this cell wall will be rough, where as the outside, or inside of bottom of next cell, will be smooth. This is supposedly useful for the larva(e) to sense its orientation before comencement of it spinning its cocoon. Pretty cool huh?
The very last layer of mud is a plug and the vestibular gap is just that, a gap before the end. The male progeny is laid at the last stages on the outside, and are smaller in size. They emerge sooner/before the females even though they were laid last. Another neat feature of nature's perfection.
