life table of the sugarcane mite oligonychus sacchari mcgregor (acari: tetranychidae) under laboratory conditions

sugarcane mite, oligonychus sacchari mcgregor, is one of the most important pests of sugarcane plant in khuzestan province, southwest of iran. during a two-year study (2007-2008), the biology of the sugarcane mite, o. sacchari, was investigated on three commercial varieties cp48-103, cp57-614 and cp69-1062 under laboratory conditions (temperature 30±1° c, rh% 60±5 and a photoperiod of 16:8 (l:d) hours). the life table and population growth parameters were calculated by using jack knife method. the results showed that the intrinsinc rate of increase (rm) , net reproductive rate (ro), mean generation time (t), finite rate of increase (λ) and the doubling time (dt) of sugarcane mite on cp48-103 variety were 0.253 , 22.02 , 12.2 day, 1.3 and 2.73 day, respectively. these rates on cp57-614 and cp69-1062 varieties were 0.23, 9.7, 9.95 day, 1.3 and 3.03 day, 0.172, 8.25, 12.25 day, 1.2 and 4.02 day, respectively. the longevity of adult female sugarcane mite on three varieties cp48-103, cp57-614 and cp69-1062 were 14.7, 18 and 18.75 days, respectively. there was a significant difference between the longevity of adult female sugarcane mites. the total mean reproductive eggs of sugarcane mite on three varieties were 41.9 , 20.1 and 16.45, respectively. also, there was a significant difference between the total mean reproductive eggs of sugarcane mite.