vsftpd block problem in deny.hosts

In deny.hosts

# finally, the command to execute the blockhosts script, based on
# connection to particular service or services:

sshd, vsftpd: ALL: spawn /usr/bin/blockhosts.py --verbose --ipblock=iptables \
--echo "%c-%s" --check-ip "%h" >> /var/log/blockhosts.log 2>&1 & \
: allow

sshd works fine, but vsftpd isnt blocked, why?

vsftpd tcp wrappers enabled?

Is vsftpd setup to work with TCP wrappers?
Doa search for vsftpd at this site, there are multiple postings about it.

For example: vsftpd and tcpd wrappers