Moved from unidentified woolly aphids. The "corrugations" shown in your second image are a characteristic sign of spiny witch hazel gall aphids, in their alternate life as fluffy things on the undersides of birch leaves.

Moved from Woolly Aphids.

Sap-sucking insects often deal with sap pressure by releasing some of the liquid (otherwise they might burst!). Mostly it hasn't been processed by their digestive systems, so it still has a lot of sugars and other nutrients in it.

Honeydew has been suggested as a possible non-supernatural explanation for the manna mentioned in the scriptures (I don't buy it). It's true that dried honeydew is still gathered from tamarisk groves in the Middle East- but not enough to live off of for long.

I've actually bought candy in an Iranian market here in the Los Angeles area (some years back) that had this tamarisk manna as an ingredient.