We monitored mite populations in three orchards in Nova Scotia that had been inoculated with pyrethroid-resistant Typhlodromus pyri. Often T. pyri was present in high numbers in tree canopies, whereas Neoseiulus fallacis were at low to undetectable levels, even though present in the ground cover and on tree trunks. The scarcity of N. fallacis in canopies was likewise seen in 11 commercial orchards also surveyed in 2002 and 2003. Sometimes low numbers were due to use of pyrethroids or to scarcity of prey, but the predominant factor was likely the abundance of T. pyri, which competes with N. fallacis and also feeds on its larvae and nymphs. The scarcity of an efficient specialist predator of T. urticae in trees means that control depends mostly on T. pyri, a generalist predator that is not particularly effective in regulating T. urticae. Remedies to the current challenge include minimizing use of pesticides toxic to the phytoseiids and adjusting practices of managing ground cover to enhance the ratio of N. fallacis to T. urticae on the ground.