Showing 13 results for Life Table Parameter
Hooshang Rafiee-Dastjerdi, Mehdi Hassanpour, Gadir Nouri-Ganbalani, Ali Golizadeh, Somaye Sarmadi,
Volume 1, Issue 3 (9-2012)
Abstract
Habrobracon hebetor Say (Hymenoptera: Braconidae) as an ectoparasitoid of larval stage of lepidopterous pests is widely used in biological control programs. In the present research, the effect of field recommended doses of imidacloprid, indoxacarb and deltamethrin were studied on life table parameters of H. hebetor in pupal stage treatment. One hundred, two-day-old pupae were treated with 1 micro liter insecticide solution using topical method. The pupae were treated with acetone in the control. Thirty emerged adults in each treatment were transferred individually to a Petri dish along with a male for mating. Three last instar larvae of Anagasta kuehniella (Zeller) (Lepidoptera: Pyralidae) were presented to each female wasp daily as host. The numbers of eggs produced per female per day were counted until all of the females were dead. The gross and net reproductive rates in control, imidacloprid, indoxacarb and deltamethrin were 204.6, 207.7, 209.1 and 112.1 and also 75, 41.3, 64.6 and 14.9, respectively. Intrinsic rates of increase were estimated to be 0.215, 0.154, 0.205 and 0.14 female offspring/female/day, respectively. Deltamethrin and imidacloprid had the most adverse effects on life table parameters of H. hebetor. Intrinsic rate of increase was not significantly affected by indoxacarb. These findings indicated that indoxacarb was relatively safe for H. hebetor and could be an appropriate candidate in integrated chemical and biological control.
Khadijeh Madahi, Ahad Sahragard,
Volume 1, Issue 4 (12-2012)
Abstract
Life table parameters of Aphis pomi DeGeer (Hemiptera: Aphididae) were determined on two host plants: apple (Malus pumila L.) and flowering quince (Chaenomeles japonica Lindl.). This study was carried out under laboratory conditions (25 ± 1 ºC and RH of 70 ± 5 % and a photoperiod of 16: 8 h (L: D). The survivorship from first instar nymphs to adult was very close in M. pumila and C. japonica. The longevity of A. pomi was 8.1 ± 0.458 and 9.65 ± 0.412 days and the fecundity of female was 37.25 ± 2.198 and 32.9 ± 1.802 nymphs on M. pumila and C. japonica, respectively. Peaks of reproductive value occurred at ages of 8 and 9 days when reared on M. pumila and C. japonica, respectively. The intrinsic rate of increase (r) on M. pumila was higher than that on C. japonica, as it was 0.396 ± 0.015 on M. pumila and 0.329 ± 0.006 day-1 on C. japonica. The mean generation time (T) was 9.13 ± 0.35 and 10.62 ± 0.18 days, on M. pumila and C. japonica, respectively. The results showed that the two closely related host plants had significant influence on life table parameters of A. pomi and the aphid showed a better performance on M. pumila than on C. japonica. These results indicated that M. pumila is more suitable for A. pomi, resulting in a higher reproductive performance.
Seyedeh Masoumeh Fotukkiaii, Ahad Sahragard, Mohammad Fazel Halajisani,
Volume 2, Issue 1 (3-2013)
Abstract
Demographic parameters of the ladybeetle, Serangium montazerii Fursch feeding on citrus whitefly, Dialeurodes citri Ashmead were determined on two host plants, Page tangerine and Thompson navel orange. This study was carried out under laboratory conditions (25 ± 1 °C and RH of 60 ± 5% and a photoperiod of 16: 8 h (L: D). Total pre-adult periods of the lady beetle were 20.84 ± 0.302, 19.27 ± 0.251days on Page tangerine and Thompson navel orange, respectively. The survivorship from egg to adult were very close to each other on the two host plants. The oviposition periods were 29.64 ± 0.905 and 33.36 ± 0.599 days and the total number of eggs per female (fecundity) were 457.14 ± 11.099 and 528.57 ± 12.369 on Page tangerine and Thompson orange, respectively. Peaks of reproductive value occurred at ages of 31 and 33 days when reared on Thompson navel orange and Page tangerine, respectively. The intrinsic rates of increase (r) on Thompson orange and on Page tangerine were 0.134 ± 0.063 and 0.126 ± 0.006d-1 with no significant differences. The mean generation time (T) on these host plants were 39.03 ± 0.5 and 40.57 ± 0.46 days, respectively. It can be concluded that S. montazerii feeding on D. citri in general showed a slightly better reproductive performance on Thompson navel orange than on Page tangerine.
Hajar Faal-Mohammad-Ali, Parviz Shishehbor,
Volume 2, Issue 4 (12-2013)
Abstract
The effect of host diet on developmental time, fecundity and life-table parameters of Bracon hebetor (Say) (Hymenoptera: Braconidae) against the Mediterranean flour moth Ephestia kuehniella (Zeller) was studied in the laboratory condition at 26 ± 1 °C, 65 ± 5% relative humidity and a photoperiod of 16L:8D h. The diets used were rice, barley, corn and wheat flours. The developmental time (egg to adult) of the first and second generations ranged from 9.00 to 14.00 days on barley flour and wheat flour, respectively. The survival of immature generations 1 and 2 ranged from 27 to 63%. The sex ratio of wasp progeny (females/total) ranged from 36.72 to 57.83% on wheat flour and rice flour, respectively. In the first and second generations, the fecundity of B. hebetor reared on barley and rice flours was greatest. Life table parameters varied significantly with host diets. In generation 2, B. hebetor-parasitized larvae reared on rice flour showed the highest net reproduction rate (R0 = 106.13) and the highest intrinsic rate of increase (rm = 0.269) of parasitoids. Based on the life-table analyses, rice flour was found to be the best diet for rearing the parasitoid. The results of this study can be used to improve mass-rearing programs of B. hebetor.
Gadir Nouri-Ganbalani, Mohammad Shahbaz, Seyed Ali Asghar Fathi,
Volume 5, Issue 2 (6-2016)
Abstract
Tuta absoluta(Meyrick) is a serious pest of tomato throughout the world. The life history and the life table parameters of T. absolutawere studied on 12 different commercial tomato cultivars. The longest larval developmental period (12.92 ± 0.11 days), the longest total developmental time (26.20 ± 0.22 days), the longest total pre-oviposition period (29.31 ± 0.63 days) and the shortest oviposition period (5.08 ± 0.43 days) were recorded on Korral cultivar. The highest pupal mortality was found on Korral (23.53%) and the lowest larval and pupal growth indices were observed on Korral (6.57and 8.87, respectively). The highest and the lowest overall mortalities were observed on Korral (35.00%) and on Valouro (21.67%), respectively. The lowest and the highest intrinsic rate of increase (rm) were found on Korral (0.1046 ± 0.0005 day-1) and on Valouro (0.1584 ± 0.0002 day-1) cultivars. Also the lowest finite rate of increase (λ) (1.1102 day-1) and the highest doubling time (6.63 days) of the tomato leafminer were observed on Korral cultivar. Therefore, it was concluded that among the 12 tomato cultivars that were studied in this research, Korral was relatively unsuitable to T. absolutaand can be used in the integrated control programs (IPM) of this pest.
Maryam Rezaie, Alireza Saboori, Valiollah Baniameri,
Volume 6, Issue 1 (3-2017)
Abstract
Neoseiulus californicus (McGregor) is a predatory mite that can control spider mites. The effect of seven strawberry cultivars (including: ‘Marak’, ‘Yalova’, ‘Aliso’, ‘Gaviota’, ‘Sequoia’, ‘Camarosa’ and ‘Chandler’) on the growth and development of N. californicus was studied in the laboratory conditions (27 ± 1 °C, 70 ± 5% RH and 16L: 8D photoperiod). There was significant difference in the number of trichomes on the leaves of strawberry cultivars. Life table parameters were analyzed based on age˗ stage, two˗sex life table. Egg incubation and protonymphal duration were significantly different when the predator was reared on different cultivars. There was no significant difference of total longevity among different cultivars. The longest preoviposition period was observed on ‘Aliso’ (1.70 days). The fecundity rate on ‘Gaviota’ and ‘Sequioa’ (6.90 and 8.91 eggs, respectively) was lower than other cultivars tested. The highest intrinsic rate of increase (0.20 day-1) and fecundity rates (13.29 eggs) were on ‘Chandler’, which might be due to the higher nutritional quality of Tetranychus urticae Koch reared on it or its low density of trichomes. Among the seven strawberry cultivars ‘Sequoia’, ‘Gaviota’ and ‘Yalova’ were recognized unsuitable for development and reproduction of N. californicus.
Narges Eini, Shahriar Jafari, Amir Mohseni Amin, Jahanshir Shakarami,
Volume 6, Issue 3 (9-2017)
Abstract
Aphis gossypii Glover is one of the major pests of cucumber in Iran. The effects of different concentrations of nitrogen (N1 = 0, N2 = 30, N3 = 60, N4 = 90 and N5 = 120 kg/ha), phosphorus (P1 = 0, P2 = 15 and P3 = 22.5 kg/ha) and silicon (Si1 = 0, Si2 = 100 and Si3 = 200 kg/ha) on life table parameters of apterous morph of A. gossypii were studied. This study was conducted as factorial experiment based on RCD with nine replications in a growth chamber at temperature of 25 ± 3 °C, 60 ± 5% relative humidity (RH) and a photoperiod of 16: 8 h (light: dark). The experiments were carried out using clip-cages that were fixed on leaves of cucumber growing in pots. According to the results, total fecundity of A. gossypii significantly was different among treatments and it was the highest on N1P2Si2 (64.33 offspring) and the lowest on N3P2Si1 (22.67 offspring). The lowest and the highest values of R0 were observed on N3P2Si1and N4P2Si2, respectively. The shortest mean generation time (T) was found on N4P1Si3 and the longest was on N5P3Si1. Furthermore, the lowest and the highest values of r were obtained on N5P3Si2 (0.27 day-1) and N5P1Si1 (0.41 day-1). Our results showed that in simultaneous application, the phosphorus had a more impact on life history and performance of cotton aphid.
Seyed Ali Safavi, Milad Bakhshaei,
Volume 6, Issue 3 (9-2017)
Abstract
Efficacy of the neonicotinoid insecticide, Calypso® was studied on eggs, nymphs and adults of Trialeurodes vaporariorum Westwood, using a leaf disc bioassay method. Concentrations from 0.15 to 0.8 ml/l were applied by systemic-contact method. Nymphs were more susceptible than eggs and adults, and LC50 and LC30 values were estimated to be 0.465 and 0.263 ml/l, respectively. Also, the longevity and fecundity of exposed females was reduced compared to control. Moreover, the demographic parameters were adversely influenced compared to control. The intrinsic rate of increase (rm) was significantly decreased to 0.132 and 0.139 day-1 at LC50 and LC30 level, compared to control (0.152 day-1). Other life table parameters (R0, λ, T, and DT) were also significantly lower in the treated insects. Sublethal concentrations of Calypso® may reduce the insecticide residuals on greenhouse crops and reduce the resistance development in greenhouse whiteflies. Therefore, these concentrations may be applicable in the management of T. vaporariorum after complementary studies.
Jabraeil Razmjou, Mahdieh Jafary , Ehsan Borzoui,
Volume 8, Issue 2 (2-2019)
Abstract
The antibiosis, host preference in free-choice situation, and digestive enzyme activity of Brevicoryne brassicae L. (Hemiptera: Aphididae) were evaluated in the laboratory (25 ± 1 °C, 60 ± 5% R. H. with a 14-h day) on nine host plants: broccoli, canola (leaf, flower, and pod), cauliflower, kohlrabi, radish, red cabbage and white cabbage. The antibiosis test was based on life table parameters and the experiment started with 50 replicates for each host plant using clip cages. The immature survival varied from 34% on red cabbage to 78% on cauliflower. The viviparous aphids reared on rapeseed (flower) had the highest GRR and R0 values, and those on red cabbage had the lowest GRR and R0 values. Also, aphids reared on rapeseed (flower) had significantly higher rm value. The lowest rm value was obtained when individuals fed upon red cabbage. In host preference experiment, rapeseed (leaf) attracted the significantly higher number of adults as opposed to radish, which attracted the lower number of adults. Females who came from nymphs reared on rapeseed (flower) were heavier than other hosts. The growth index of nymphs varied from 0.035 to 0.103, with the minimum on red cabbage and the maximum on cauliflower. The amylolytic activity in adults was higher on rapeseed (flower) and the lowest on red cabbage. In addition, the highest and lowest proteolytic activity was on rapeseed (flower) and red cabbage, respectively. The results of this study indicated that red cabbage was an unsuitable host for feeding of B. brassicae.
Yaghoub Fathipour, Maryam Babaei, Abdoolnabi Bagheri, Ali Asghar Talebi, Shima Yazdanpanah,
Volume 10, Issue 2 (2-2021)
Abstract
The cotton bollworm, Helicoverpa armigera (Hübner), is a destructive pest feeding on a diverse array of host plants. We studied the demographic parameters of H. armigera on artificial diets prepared from seeds of 10 corn Zea mays L. hybrids (KSC301, KSC403, KSC540, KSC600, KSC604, KSC704, KSC711, Maxima, NS770, and ZP677) using the age-stage, two-sex life table procedure. The results revealed that except for the incubation period, the Z. mays hybrids-mediated artificial diets significantly affected the length of the other immature stages. They also influenced the adult longevity, adult pre-oviposition period (APOP), total pre-oviposition period (TPOP), and oviposition days of H. armigera. Furthermore, the total fecundity of H. armigera was affected by Z. mays hybrids. Accordingly, the females reared on KSC711 with 503.31 eggs had the highest total fecundity. The highest net reproductive rate (R0) (88.41 eggs/individual), the intrinsic rate of increase (r) (0.109 day-1), and finite rate of increase (λ) (1.115 day-1) were observed on KSC711. Our results provided valuable information regarding the life cycle of H. armigera on an artificial diet substrate prepared from different Z. mays hybrids. It was also revealed that although H. armigera had no significant differences in life table parameters on most hybrids, some of them, such as KSC711, were very susceptible to damage. One of the issues that emerged from these findings is the possibility of using some hybrids, e.g., KSC711, in the preparation of semi-artificial diets for this pest.
Volume 15, Issue 4 (7-2013)
Abstract
Development, reproduction and life table parameters of Tetranychus urticae Koch were determined on leaves of peach (G. H. Hale cultivar) at different temperatures, ranging from 13 to 33°C under laboratory conditions. No development was observed at 13°C. Egg-to-adult developmental time decreased gradually from 17 to 27°C and increased at higher temperatures (27 to 33°C). An average of 136.43 degree-days was required to complete development above the lower threshold temperature (13.79°C). Mean total egg productions per female were 40.09, 18.74, 8.03 and 21.33 at 25, 27, 30 and 33 °C, respectively. Mean longevities of the females were 12.91±1.65, 5.92±0.55, 3.56±0.54 and 6.53±0.56 days, respectively at the above mentioned temperatures. The intrinsic rate of increase (rm) at different temperatures ranged from 0.108 to 0.213 day -1, with the highest value recorded at 27 °C. The highest and the lowest values of the net reproductive rate (R0) were obtained at 25°C (16.87) and 30°C (4.18), respectively. Doubling time (DT) varied significantly at different temperatures and the shortest and longest values of this period were obtained at 27 and 30°C, respectively. The results suggested that T. urticae was able to develop and reproduce within a wide range of temperatures, and that temperatures from 27- 30°C are the most suitable conditions for the development, survivorship and reproduction of the mite.
Volume 17, Issue 1 (1-2015)
Abstract
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 green house conditions. Nitrogen fertilization treatments were 0, 75, 150, and 225 kg N. ha-1. The results showed that increased nitrogen fertilization resulted in enhancing plant nitrogen content and decreasing of C/N ratio of leaves. Based on N-content and C/N ratio, Zarfam had the highest nutritional quality for herbivore among the tested canola cultivars. Fertilization generally increased the susceptibility of plants to mustard aphid. Therefore, aphids feeding on plants receiving higher nitrogen levels had shorter nymphal developmental time, longer adult longevity as well as greater fecundity. The highest and the lowest values of aphids’ intrinsic rate of increase (rm) were calculated on Zarfam and Modena cultivars, respectively. Moreover, nitrogen fertilization positively affected rm of aphids on all canola cultivars. According to our results, management of nitrogen fertilization and cultivation of resistant cultivar could be suitable eco-friendly strategies to manage mustard aphid population.
Volume 18, Issue 7 (12-2016)
Abstract
Demographic parameters of the pink stem borer, Sesamia creticaLederer (Lepidoptera: Noctuidae) were estimatedon its two main host plants, maize and sugarcane. The present studywas conducted under laboratory conditions at 27±1˚C, 50±10% Relative Humidity (RH %), and a photoperiod of 0:24 (L:D) hour for the larval stage and 16:8 (L:D) hour for the other life stages. The raw data were analyzed based on the age-stage, two-sex life table theory. For estimating the SE of the population parameters, the bootstrap technique was applied. Total pre-adult developmental periods of the pink stem borer were51.95 and 39.51 days on maize and sugarcane, respectively. The oviposition periods were 5.03 and 5.38 days and fecunditywas 118.04 and 142.88 eggs on maize and sugarcane, respectively. Peaks of reproductive value occurred at ages 49 and 38days when reared on maize and sugarcane, respectively.The net Reproductive rate R0, intrinsic rates of increase r and finite rate of increase λ of S. cretica were 53.58 offspring, 0.0937 day-1 and 1.0983 day-1 on sugarcane and 39.54 offspring, 0.0672 day-1 and 1.0695 day-1 on maize, respectively. Themean generation Time (T) of the pink stem borer was 42.41 and 54.57 days on sugarcane and maize, respectively. There was significant difference between demographic parameters of S. cretica on maize and sugarcane. The results showed that there was higher reproductive performance and population growth of S. cretica on sugarcane than on maize.
