Can't see Micro SD card .

Hi I have an microsd card reader plugged in with usb.
But when i insert my microsd card I can’t see it in Dolphin.
Do I have to mount it first? and how?
and is it possible let it be mounted automaticly when I insert the card?
Thanks in advance.

Check the settings of your device-manager-Plasmoid (or add it if not present yet), it will offer you an option to automount plugged media automatically.

In case this won’t work, remove the card, open a console, become root and

tail -f /var/log/messages

…then plug the card in again. Post the lines which (hopefully) appear then.