Trehala manna

C,2H220ii,2H20. M.p. 9TC. A non-reducing disaccharide, which forms the principal carbohydrate of insect haemolymph. It comprises about 25% of trehala manna, the cocoons of a parasitic beetle. Trehalose also occurs in fungi, e.g. Amanita muscaria, generally replacing sucrose in plants lacking chlorophyll and starch. 

What exactly was manna Its sweetness, and the fact that it was available in an arid land, suggests it was rich in trehalose. This being so, then there are several possible sources. It may have been the cocoon of a parasitic beetle, called trehala mana, which contains around 25% trehalose. A possible contender is the solidified juice of the flowering ash, also known as the manna ash (Fraxinus omus) which oozes from its bark and solidifies. This too is collected and sold commercially. Another suggestion is that manna is the lichen Lecano-ra which curls up into balls when there is a drought. These can be blown by the wind and are sometimes collected and used to make... 

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