the use of praying mantis egg case as a medicine is described in the "shennong bencao jing", a pharmacological treatise on chinese herbology from circa 100 ad. their medicinal use might originate from their occasional occurrence on the mulberry plant "morus alba". as its leaves were necessary food for the caterpillars that make silk, much of the plant – including branches, fruits, leaves, and root bark – became revered in ancient china as source of herbal medicine. says one source, "it would not be surprising that these egg cases, which appeared on some of the plants, were also collected and considered a valuable medicine."