Hi Josh, thanks for commenting.
Yes, you would harvest the whole tray. Let me compile some links and post them, that would probably be helpful to others as well.
Until then, here’s a brief expansion on the operational side of things:
The whole operation is similar to any farming operation out in a field, but the difference is that you’re responsible for keeping and maintaining your “seed crop”, or in this case, the adults that lay the eggs. The operation thus relies on the breeding rate of the beetles.
A reasonable number to consider is about 1-1.5% of your harvest is set aside to pupate and turn into adults (each female lays 200-500 eggs). The adult bins will have screening that is small enough to have the eggs and the newly hatched larvae drop into a bin below. Each week these new bins are brought to the growing area for the larvae to grow to harvest size.
Larvae take about 50 days to grow to “market size”, though this varies, and size is unimportant if they’re being converted to flour.
At harvest time, the entire bin is brought to a screen and dumped to separate the wheat bran (their feed), shed exoskeletons, and the larvae.
They are then cleaned, frozen to kill, flash boiled, and dehydrated for packing or milling.
Hope this helps!