a quarantine restriction
... that California and the entire eastern United States are under a quarantine restriction by the U.S. state of Washington designed to protect it from apple maggot infestation?
... that California and the entire <a href="./Eastern_United_States" id="mwBDQ" rel="mw:WikiLink" title="Eastern United States">eastern United States</a> are under <b id="mwBDU"><a href="./Apple_Maggot_Quarantine_Area" id="mwBDY" rel="mw:WikiLink" title="Apple Maggot Quarantine Area">a quarantine restriction</a></b> by the U.S. state of Washington designed to protect it from <a href="./Apple_maggot" id="mwBDc" rel="mw:WikiLink" title="Apple maggot">apple maggot</a> infestation?