Christmas tree pests and weeds required restrictions and requirements to be placed upon Christmas tree growers with plantations in "gypsy moth regulated areas". The restrictions and requirements included ongoing site monitoring, active moth eradication by the grower, accurate record keeping, and government directed moth eradication programs. Failure to abide by the rules could result in revocation of the "approved grower" status from the Canadian Food Inspection Agency. The major types of conifers cultivated, pines, Douglas-firs, true firs, and spruce trees, are all affected by some types of insect pests. Douglas-firs are most vulnerable to the Cooley spruce gall adelgid. The true firs are most susceptible
Knagenhjelm (noble family) Manor ("Kaupanger Hovedgård") in Sogn og Fjordane and are included in the Yearbook of the Danish Nobility ("Danmarks Adels Aarbog"). Before he became noble, Niels Tygesen Knag had only a tree trunk as his arms (Hans Krag. 1942). The coat of arms was received upon the ennoblement in 1721. Description without the heraldic terminology: "On a blue shield a tilted, chopped and knotty silver tree trunk beside or above which there are three golden stars in each of two bends. On the helmet is a six-pointed star between two buffalo horns divided in gold and blue, vice versa, respectively." Some