جستجوی مقالات مرتبط با کلیدواژه « گیاهان میزبان » در نشریات گروه « کشاورزی »

In this study, the effect of five host plants on the biology and food consumption of the fall armyworm Spodoptera frugiperda (Smith) (Lepidoptera: Noctuidae) was evaluated in Egypt. Developmental periods and weight of different growth stages, percentages of pupation and adult emergence, survival, and nutritional indices were evaluated on maize, castor oil, clover, broad bean, and lettuce. The results showed that the developmental period of S. frugiperda was significantly longer on the broad bean. The pupation percentage of S. frugiperda was significantly affected by the host plant. In contrast, the adult emergence was not significantly different on host plants. Our result also showed maximum weights in food consumption, and frass occurred in the larvae fed on lettuce. While the lowest weights for consumption were observed in larvae on maize and broad bean resulting in minimum frass weights. The highest percentage of approximate digestibility (AD) of the larvae was on broad bean and clover, and the lowest AD was by larvae fed on maize. The highest percentages of conversion of ingested food (ECI) and conversion of digested food (ECD) were observed for larvae fed on maize leaves. The lowest values of ECI and ECD were observed on larvae fed on broad bean leaves. Based on the results, it seems that lettuce, castor, and maize were preferred for S. frugiperda.

In this study, the nutritional indices of the larval stages of Helicoverpa armigera were determined on four vegetable crops under laboratory conditions (25 ± 1 °C, 65 ± 5% RH, with a 16:8 (L: D) h photoperiod). The third instar larvae reared on potato showed the highest value of efficiency on the conversion of ingested food (ECI) and efficiency of conversion of digested food (ECD) (8.281 ± 0.767% and 11.016 ± 1.142%, respectively). The highest (0.129 ± 0.014 mg/mg/day) and lowest (0.069 ±0.012 mg/mg/day) relative growth rate (RGR) of the fourth instar larvae were obtained on potato and tomato, respectively. Data indicated that the highest value of (ECI) and (ECD) for fourth instar larvae were on tomato (12.361 ± 2.258% and 18.588 ± 3.834%, respectively). The lowest value of the relative consumption rate (RCR) and approximate digestibility (AD) of the fifth instar was recorded on tomato (0.592 ± 0.063 mg/mg/day) and potato (51.85 ± 4.607%), respectively. The ECI and ECD values of the fifth larval instar were the highest on tomato (12.477 ± 1.333% and 17.624 ± 1.609%, respectively). Overall, among different host plants tested, the highest ECI and ECD of all the larval instars were observed on tomato (9.813 ± 0.692% and 12.506 ± 0.882%, respectively), and the lowest values (3.735 ± 0.201% and 5.463 ± 0.426%) were on artichoke. Tomato and artichoke were the most nutritionally suitable and unsuitable host plants, respectively, for H. armigera.

Lady beetles are the most important predatory species among arthropods, so studying their population parameters gives a clear picture about their life span. The life histories of variegated lady beetle, Hippodamia variegata (Goeze), fed on the English grain aphid, Sitobion avenae Fabricius, on different host plants were studied under laboratory conditions, at 25 ± 1 °C, 65 ± 5% Relative Humidity and a photoperiod of 16:8 (Light: Dark) h. Developmental, survival and fecundity data were analyzed using the age-stage, two-sex life table method. According to the age-stage, two-sex life table, the net reproductive rates (R0) of ladybird fed on S. avenae reared on Triticum aestivum var. tajan, Hordeum vulgare var. Dasht, Zea mays var. single cross 704 and Sorghum durra var. Speed feed were estimated to be 235.38 ± 36.15, 190.74 ± 33.37, 293.54 ± 46.66 and 137.46 ± 23.66 female offspring / female, respectively. Based on the results, the intrinsic rate of increase as an index of population increase of H. variegata, was 0.181 ± 0.006, 0.179 ± 0.006, 0.163 ± 0.006 and 0.162 ± 0.006 h-1 preyed on host reared on T. aestivum var. tajan Z. mays var. single cross 704 S. durra var. Speed feed and H. vulgare var. Dasht, respectively. Our findings demonstrate that by using the age-stage, two-sex life table we can accurately describe the growth, survival and development of the predator. Our finding may provide basic information for developing aphid biological control programs.