Biology, life table and host specificity of the mushroom pest, Brennandania lambi (Acari : Pygmephoroidea)

Biology and life table parameters of Brennandania lambi (Krczal) were studi ed at different temperatures while feeding on white mushroom (Agaricus bisp orus) mycelium cultured on mushroom compost. The duration of egg and larva development, preoviposition and oviposition period, female longevity, and t he time to 50% mortality declined as temperature increased from 16 to 28 de greesC. The threshold temperature of development (female) was 9 degreesC an d the thermal constant for completion of development (female) was 195 day-d egrees. At 16, 20, 24 and 28 degreesC, the total fecundity (eggs/female) wa s 71, 67, 66 and 57, respectively and the daily fecundity rate (eggs/female /day) was 5.6, 8.7, 8.7 and 9.1, respectively. The sex ratio (female/male) ranged from 1.9 to 2.1 at 16-28 degreesC. At 16, 20, 24 and 28 degreesC, th e intrinsic rate of natural increase (r(m)) was 0.11, 0.18, 0.22 and 0.27, respectively, and the population doubling time was 6.1, 3.9, 3.2 and 2.5 da ys, respectively. All life stages of the mite died when exposed to 35 degre esC constant temperature for 24 h, or to 32 degreesC constant temperature f or 12 days or to 31-35 degreesC (average 32.9 degreesC) ambient temperature for 4 days. Brennandania lambi completed development only when fed on Ag. bisporus mycelium growing on mushroom compost. It could not survive on mush room mycelia of Auricularia auricula, Au. polytricha, Ganoderma lucidum, He ricium erinaceus, Lentinus edodes, Pleurotus ostreatus, P. sajor-caju and T remella fuciformis.