missing /usr/local in startup.sh files

[David Banning]

All of a sudden I notice that whenever I install a package from the
ports, the startup file in /usr/local/etc/rc.d requires that I
put /usr/local in - for instance, the most recent install of 
clamav I had to change

. /etc/rc.subr

to 

. /usr/local/etc/rc.subr

there must be a variable or setting for this that went missing for me.
Could someone be kind enough to direct me here?