the life table parameters of schizaphis graminum (rondani) (hemiptera: aphididae) on four commercial cultivars of wheat (kohdasht, pastor, tajan and zagros) were determined in laboratory conditions. fertility life table were constructed using age-specific survivorship (lx) and age-specific fecundity (mx) and subsequently analyzed using jackknife method and anova. there were significant differen...

effects of four pesticides (imidacloprid, dichlorvos, pymetrozine and abamectin) were evaluated on life table parameters of orius albidipennis (reuter). pesticides were used at the concentrations recommended by the manufacturers. the bioassays were carried out using drum-cell method, in a growth chamber at 27 â± 1âºc, r.h. of 65 â± 5% and 16 h photo phase. the net reproductive rate (r0) value f...

the tomato fruit borer, helicoverpa armigera (hã¼bner), is a destructive insect pest of many host crops in iran and worldwide. the effect of different tomato cultivars (sun 6108 f1, rio grande ug, korral, ch falat, hed rio grande and cal jn3) was studied on life table parameters of h. armigera under laboratory (25 â± 1 â°c, 65 â± 5% rh and a photoperiod of 16: 8 (l: d) hours), and on the activi...

due to the limitations of the “life table method” the exponential model was used to estimate the iud termination and retention rate among 1,390 women. since the conditional probability of iud termination during the first month of insertion is considerably higher than the subsequent months, data relating to the first 30 days was considered separately. furthermore a constant termination rate was ...

the effect of eight cucumis l. (cucurbitaceae) genotypes, including native cucumber genotypes (hormozgan, bushehr and gilan), greenhouse cucumber genotypes (girtap, negeen, sepehr and pouya) and armenian cucumber (cucumis melo var. flexuosus) was studied on the life table and population growth parameters of aphis gossypii glover to evaluate antibiosis resistance. the experiment was conducted at...

A method is presented for estimating age-specific mortality based on minimal information: a model life table and an estimate of longevity. This approach uses expected patterns of mammalian survivorship to define a general model of agespecific mortality rates. One such model life table is based on data for northern fur seals (Callorhinus ursinu.r) using Siler’s ( 1979) 5-parameter competing risk...