well, books tell me that females have spots on the upper wing...
I don't think that quite right
Males have One spot on their wings while on the other hand females have multiple.
They are simply called a male or a female butterfly.
The pelvis is a key indicator for determining the sex of a skeleton. In general, male pelvises are more robust and narrower, while female pelvises are wider and have a broader pubic angle. Additionally, other indicators such as skull features and long bone dimensions can also be considered.
A young butterfly is called a caterpillar, larva, chrysalis or pupa
The eggs would not hatch if not fertilised by a male. A female butterfly will lay her eggs only after being fertilised by a male butterfly.
You can tell the difference between a male and female Monarch butterfly by examining their wings. The male Monarch butterfly has two black spots on its wings while the female does not. The male also has thinner vein lines through its wings than the female.
the male is bigger than the female
The eggs would not hatch if not fertilised by a male. A female butterfly will lay her eggs only after being fertilised by a male butterfly.
The color is Blue
The male Monarch has a black spot on each wing the female does not.
To attact the female for mating
Butterflies do not fall in love. Male butterflies are attracted to female butterflies through scent and sight. They pair/mate and the male goes to search for another female soon after. They have an instinct to pair/mate but never stay around one specific butterfly.
One way is that a male has two small dots on their bottom wing, while a female doesn't.