Seasonal abundance and feeding efficiency of the false spider mite Tenuipalpus pernicis (Chaudhri, Akbar and Rasool) on guava (Psidium guajava)

Abstract

The false spider mite (Tenuipalpus pernicis) population size was average in November, 2007 – January, 2008 on guava (Psidium guajava) (17.9 ± 0.33 mites / 6.25 cm2 and 15.4 ± 0.43 mites / 6.25 cm2 respectively). It peaked during May, 2008 (32.8 ± 0.28 mites / 6.25 cm2, mean ± SD is calculated) when the mean temperature, RH and rainfall were 31.28 0C, 72.62% and 1.05 mm, respectively. The population density started to decline thereafter with the minimum in August, 2008 (4.5 ± 0.51 mites /6.25 cm2) when the mean temperature, RH and rainfall were 28.910C, 84.50% and 15.53 mm. respectively. Heavy precipitation in June and July probably adversely affected the mite population. Correlation of the mite density with temperature and relative humidity (RH) were positive while that with rainfall was negative.Correlation with RH was non-significant. We quantified the decrease in chlorophyll, proteins, carbohydrates and minerals in guava leaves due to mite infestation.