From Chao's perspective, the virtues of the silkworms are: they are much larger than cabbage caterpillars; they are amenable to genetic engineering; and they are easily controlled.
趙裕展看中的，除了蠶寶寶體型遠比菜蟲碩大，容易進行基因工程外，主要也是家蠶的易於控制。