Biological Studies on Two- Spotted Spider Mite, Tetranychus urticae, Reared on Nine Tomato Cultivars during Fruiting under Laboratory Conditions



Biological reactions of the two-spotted spider mite (TSS), Tetranychus urticae, were studied on nine cultivars of tomatoes. The spider mites were reared on leaf discs, taken from fruiting stages of the host plants. The effects of feeding on some tomato cultivars, namely: Long shelf life, Meran (greenhouse cultivars), Redclude, Western red, Imperial, Yazd, Mazandaran, West Azarbaijan and Khorasan (cultivated cultivars) were evaluated for the traits of: incubation period, total number of eggs produced, number of eggs per day, percentage of egg hatching, oviposition period, pre oviposition period, post oviposition period, larval period, percentage of larval mortality, duration of protonymph development, percentage of protonymph mortality, duration of deutonymph development, percentage of deutonymph mortality, female life span, male life span, sex ratio (female/total) for two generations. The experiment was performed as split plot, using a randomized complete block design (RCBD) with three replicates. Statistical analysis indicated that Meran, Yazd, Mazandaran, Khorasan, Imperial, Western Red, Long Shelf Life, West Azarbaijan and Redclude were the undesirable cultivars to TSSM respectively. According to cluster analysis for the two generations of mite, Mazandaran, Yazd, Imperial, Khorasan and Meran cultivars appeared to be the unsuitable hosts to TSSM while Long shelf life, Western red, Redclude, West Azarbaijan regarded as suitable.