according to the
BitCore GitHub, the format for the send command is:
wallet send 1xxxxx 1000bit "1000 bits to mother"
Why are you using the -f command? Looking at the "send" code... The argument list is fixed:
https://github.com/bitpay/bitcore-wallet/blob/master/bin/wallet-sendamount = utils.parseAmount(args[1]);
Fairly sure you shouldn't be using -f to specify wallet....