Bombyx hybrid
The "Bombyx" hybrid is a hybrid between a male "Bombyx mandarina" moth and a female "Bombyx mori" moth. They produce larvae called silkworms, like all species of "Bombyx". The larvae look a lot like the other variations. They are brown in the first half and gray at the bottom half, but they get larger black spots than other variations. Generally, they look like a normal "Bombyx" moth, but a bit darker. Hybrids are not used for silk, but for research. Because "Bombyx mori" males lost their ability to fly, their females are much more likely to mate with  a male "Bombyx mandarina". The reverse is possible, but both species have to be kept in the same container. Since "Bombyx" hybrids are much more common than the other variation, more is known about them. The domestic silkmoth ("B. mori") was domesticated from the wild silkmoth ("B. mandarina") more than 5,000 years ago.