billrussell42
There is no reason to insulate the ends. The center, there are two legs, connected to the two wires of the feedline. If you connect them together, you will short across the connector and get no signal. ,

Technobuff
In the word dipole, "di" means 2. A dipole is a 2- element antenna, each 1/4 wavelength long. So they need separation at the centre, which is the feed point for a balanced transmission line. The end insulators are necessary to allow electrical separation from metal or even timber or tree supports, as the ends of a dipole used for transmission are at a high voltage level. It is hardly an expensive exercise to supply end insulators, even if the antenna is only used for receive functions. A very cheap type "egg" insulator can be found in retailers of electric fence components, or you could use ceramic ones scrounged or bought, but they are relatively expensive. The centre insulator also provides a good anchor for a balun if used with coax cable feedline, and a firm attachment for it.