<Tr> <Td> - Zygentoma <200 </Td> </Tr> <Tr> <Td> - Monura </Td> </Tr> <Tr> <Td> Pterygota </Td> <Td> <Table> <Tr> <Th> (show) Paleoptera </Th> </Tr> <Tr> <Td> - Ephemeroptera - 2,500--<3,000 </Td> </Tr> <Tr> <Td> - Odonata - 6,500 </Td> </Tr> </Table> </Td> </Tr> <Table> <Tr> <Th> (show) Paleoptera </Th> </Tr> <Tr> <Td> - Ephemeroptera - 2,500--<3,000 </Td> </Tr> <Tr> <Td> - Odonata - 6,500 </Td> </Tr> </Table>

An insect is divided into how many parts