Chromosomal pattern for female silk worm is

Chromosomal pattern for female silk worms is ZW.
In silkworms, the female is the heterogametic sex and has one Z and one W chromosome, whereas the male has two Z chromosomes.
In this system the genetic sex of an offspring is determined by a pair of sex chromosomes, always a Z from the father, and either a Z or W from the mother. The ZW system is opposite of the XY system in that the mother's sex chromosome determines the genetic sex of the offspring.