Simplify the following text for a Grade 9 native English-speaking person.
Original: Like the Papilionidae , Pieridae also have their pupae held at an angle by a silk girdle , but running at the first abdominal segment unlike the thoracic girdle seen in the Papilionidae .
Simplified: Like the Papilionidae , Pieridae also have their chrysalids held at an angle by a silk girdle . The girdle runs around the first abdominal segment unlike the thoracic girdle seen in the Papilionidae .