Acaricidal activities of plant essential oils from three plants on the mushroom mite,Luciaphorus perniciosus Rack (Acari: Pygmephoridae)

Essential oils of litsea cubeba,litsea salicifolia and melaleuca cajuputi were tested against luciaphorus perniciosus by contact and fumigation methods. contact toxicity bioassay was made by dropping essential oils at rates of 0,0.06,0.33,0.66,3.3,6.6,33,66 and 99 μl/cm2 into special mite cages. fumigation was done in a knockdown chamber of 2.5x104 cm 3 in size at the concentrations of 0,0.0012,0.006,0.012,0.06,0.12,0.6 and 1.2 μg/cm3. the essential oil of l. cubeba was found to be the most toxic to l. perniciosus by both contact and fumigation methods with ld50 values equaling to 0.932 and 0.166 μg/cm3,respectively,followed by essential oil of l. salicifolia whose ld50 values of 2.793 and 0.410 μg/cm3 were recorded. essential oil of m. cajuputi demonstrated a low effect on l. perniciosus as compared to those of l. cubeba and l. salicifolia. essential oil formulations were delivered by using citronella grass or black pepper oils as major components and l. cubeba as minor component. mite mortality rate increased when 0.01% l. cubeba oil was added to either citronella grass or black pepper oil at all treatments by contact method. copyright 2010 zoological society of pakistan.