to provide reliable information concerning reproductive potential of hippodamia variegata goeze and its prey (aphis fabae), their related life tables were studied under controlled laboratory conditions (at 23?c). the unprocessed data of life tables were analyzed taking the euler-lotka as the basis model. standard error of population growth parameters was calculated using the jackknife re-sampli...

a castanea crenata agglutinin (abbreviated as cca) was extracted and purified from bitter apple, citrullus colocynthis l., to determine its effects on the demographic parameters of apomyelois ceratoniae zeller. two groups of first larval instars were reared on an artificial diet containing 2% (w/w) of cca and control diets until emergence of adults. two sex ms-chart life table software was used...

melon ladybeetle, epilachna chrysomelina (f.), is one of the key insect pests of cucurbit crops in asia and north africa. the development and reproduction of e. chrysomelina were studied on watermelon, snake cucumber, cucumber and melon under laboratory conditions. mean total life cycle from egg to adult female was 21.3, 21.7, 26.0, and 21.3 days on the mentioned host plants respectively. mean ...

background: previous studies indicate a high incidence of digestive cancers along southern parts of caspian sea including ma­zandaran province. the present study was conducted to further investigate time to occurrence, age distribution and pos­sible risks associated with the incidence time of digestive cancers in the above regions. methods: for this purpose the data of digestive cancer incidenc...

spodoptera exigua (hübner) was studied in laboratory (25±1ºc, 60±5% rh, and 16:8 l:d h) exploring the antibiotic effects of 10 canola cultivars (sarigol, slm046, hayula420, rgs003, opera, okapi, licord, modena, zarfam and talaye) on its demographic parameters. the age-stage, two-sex and the traditional female age-specific life tables were constructed by using the demographic data. the larval pe...

increased nitrogen applications to crops influence plant-herbivore interactions and potentially increase herbivore population growth.in this research, the impact of nitrogen fertilizations on nutritional quality of three canola (brassica napus l.) cultivars (zarfam, okapi and modena), and, consequently, the performance of mustard aphids, lipaphis erysimi kalt., on them were investigated under g...

Abridged life tables centred on 1991 were produced from the 1991 Canadian census, net census undercoverage estimates, and death data from 1990 to 1992. The sensitivity of life table values to differing methods of estimation and population estimates was investigated. The results from four methods by Greville, Chiang, and Keyfitz were compared, and population estimates, both adjusted and unadjust...

502 are reproduced in Table 2, with EDR converted to a decimal annual rate, and mean annual values ofq and q’ calculated as d/E and d’/E, respectively.

Life expectancy is a useful indicator of mortality for policy-makers, though its calculation for small populations is problematic. In the UK, two technical reports, one from the Office of National Statistics (ONS), and the other from the South East Public Health Observatory (SEPHO), were commissioned to investigate life table methods applied to small populations. As a result, the ONS published ...