Water activity-temperature relationships are reported for Yukon soil-isolated strains of Mortierella alpina and Penicillium expansum that are natural enemies to larvae(infestation stage)of the winter tick Dermacentor ...Water activity-temperature relationships are reported for Yukon soil-isolated strains of Mortierella alpina and Penicillium expansum that are natural enemies to larvae(infestation stage)of the winter tick Dermacentor albipictus.Both fungal strains are psychrotrophs,characterized by low thermal growth ranges,consistent with their occurrence in Yukon soil.In contrast to P.expansum,M.alpina is more temperature sensitive,has a higher requirement,and is more virulent to tick larvae.Researchers and Biological Control Officers should note that for tick population control these M.alpina and P.expansum strains grow and sporulate well under moderate temperature and humid conditions.Our experiments used Met52®Bioinsecticide as a positive control,and this is the first study that demonstrates the effectiveness of this commercial product against winter tick larvae.展开更多
文摘Water activity-temperature relationships are reported for Yukon soil-isolated strains of Mortierella alpina and Penicillium expansum that are natural enemies to larvae(infestation stage)of the winter tick Dermacentor albipictus.Both fungal strains are psychrotrophs,characterized by low thermal growth ranges,consistent with their occurrence in Yukon soil.In contrast to P.expansum,M.alpina is more temperature sensitive,has a higher requirement,and is more virulent to tick larvae.Researchers and Biological Control Officers should note that for tick population control these M.alpina and P.expansum strains grow and sporulate well under moderate temperature and humid conditions.Our experiments used Met52®Bioinsecticide as a positive control,and this is the first study that demonstrates the effectiveness of this commercial product against winter tick larvae.