As it turns out, the name “Cydia” has some very interesting etymology, originating from the Latin Cydia pomonella, which is the scientific name for the coddling moth.
The coddling moth is a pest famous for its larva, the infamous apple worm (as depicted by many children’s books). It’s a very fitting name for an application that is designed to plant itself in the nether regions of Apple’s operating systems (this administrative privilege is known as root access—which also has an apt double meaning).
The codling moth (Cydia pomonella) is a member of the Lepidopteran family Tortricidae. They are known as anagricultural pest, their larva being the common apple worm or maggot. It is native to Europe and was introduced to North America, where it has become one of the regular pests of apple orchards. It is found almost worldwide.
Steve Jobs used to work on an apple orchard, and likely had to deal with the annoying Cydia pomonella on a daily basis, much like he has to deal with its software counterpart today. That must really… bug him.