The response of common bean (Phaseolus vulgaris L.) to salinity and drought stresses and life table parameters of Tetranychus urticae Koch reared on it

2021 ◽  
Vol 26 (1) ◽  
pp. 62-74
Author(s):  
Samira Khodayari ◽  
Narmila Nematollahi ◽  
Fatemeh Abedini ◽  
Farzad Rasouli

Plants in nature are constantly exposed to various stresses resulting from fluctuating environmental conditions which adversely affect their growth and development and may affect the performance of herbivores feeding on them. Drought and salinity are the most serious problems of agriculture due to climatic changes. According to global warming and drying of Urmia salty lake in Northwestern Iran which could result in salinization of agricultural lands nearby, the focus of this study was to examine the effect of two above mentioned stresses on a host plant and its pest population. Three levels of salinity (50 (low), 100 (intermediate) and 150 (high) mM NaCl) and water deficit (40–50% the amount of water given to control plants) were induced to common bean (Phaseolus vulgaris) as stress factors and the following characteristics were measured: fresh and dry weight, leaf area, chlorophyll, carotenoid, proline and protein contents and CAT, APX and GPX enzyme activities. The life table parameters of two-spotted spider mite, Tetranychus urticae Koch, reared on stress-induced plants were measured and compared with control. The high saline condition caused plant defoliation and was deleted from results. The low saline condition caused an increase in fresh weight and decrease in chlorophyll and protein contents of plant. Intermediate saline condition caused an increase in APX and CAT enzyme activities and decrease of dry weight, chlorophyll, protein and proline contents. Drought condition caused an increase of APX and GPX enzyme activities and proline content and decrease of dry weight and chlorophyll content. Analysis of life table data of T. urticae showed a significant decrease of net reproductive rate (R0), mean generation time (T) and gross reproductive rate (GRR) of mites reared on plants under both of stresses. The intrinsic rate of increase (r) and finite rate of increase (λ) decreased significantly only for mites reared on plants under intermediate saline condition.

2018 ◽  
Vol 23 (8) ◽  
pp. 1627
Author(s):  
Atefeh Dahmardeh ◽  
Malihe Latifi ◽  
Rohollah Saberi Riseh

In this study the effects of soil application of potassium phosphite, amino acid complex, and biolog siderophoric on the life table parameters of Tetranychus urticae have been investigated on bean plants, under laboratory conditions. The results revealed significant differences in the total developmental times, oviposition periods, and fecundity of T. urticae among the treatments. The shortest total developmental time and longevity was observed in biolog siderophoric treatment. The intrinsic rate of increase, the net reproductive rate, the finite rate of increase and the mean generation times of T. urticae were remarkably different among the treatments and lower than in the control. The lowest values of these parameters were observed in the biolog siderophoric treatment, which suggests that this inducer could be employed toward a sustainable management of T. urticae.


2017 ◽  
Vol 22 (10) ◽  
pp. 1698 ◽  
Author(s):  
Sahar Saemi ◽  
Hasan Rahmani ◽  
Aurang Kavosi ◽  
Hsin Chi

To better understand the effect of individual- and group-rearing conditions on predator performance, we studied the life table and predation rate of the predatory mite, Phytoseiulus persimilis Athias-Henriot, after the mites had been individually- or group-reared on two-spotted spider mites, Tetranychus urticae, eggs at 25±1°C, 65±5% RH and a photoperiod of 16: 8 (L:D) h. The net reproductive rate (R0), intrinsic rate of increase (r), net predation rate (C0), finite predation rate (ω) in the individually-reared predators were 40.61 offspring, 0.2594 d-1, 437.3 T. urticae eggs, and 4.8668 preys/d, respectively. Similar values were obtained when the predators were reared in groups (R0 = 43.10 offspring, r = 0.2837 d-1, C0 = 420.9 T. urticae eggs, and ω = 5.9054 preys/d). Mean adult longevities were 28.42 and 25.29 d for group-reared male and female predators, respectively; these values were significantly shorter than those of individual-reared mites (49.87 d for male and 36 d for female). Our results showed that P. persimilis mites could be group-reared in biological control programs without negative effect on their growth and predation potential. 


2013 ◽  
Vol 2013 ◽  
pp. 1-7 ◽  
Author(s):  
Soodeh Davoodi Dehkordi ◽  
Ahad Sahragard ◽  
Jalil Hajizadeh

Life table gives the most comprehensive explanation of the survivorship, development, and reproduction of a population. The life table parameters of ladybeetle, Hippodamia variegata (Coleoptera: Coccinellidae), on different densities (20, 40, 60, 80, and 100) of third instar nymphs of Aphis gossypii were studied in a growth chamber (°C, % RH, and a photoperiod of 16L: 8D h). The adult preovipositional period and the total preovipositional period of female H. variegata were reduced as the prey density increased. The oviposition period was longer when prey density increased. Female longevity also increased significantly with increasing prey density. Fecundity was dependent on prey density. The lowest fecundity was obtained at density of 20 prey () and the highest at density of 100 ( eggs). Intrinsic rate of increase was dependent on prey density and ranged from to  d−1 (female/female/day) with increasing prey density. Net reproductive rate and gross reproductive rate were also increased with increasing prey density. The peak reproductive values were dependent on prey density. However, mean generation time decreased as prey density increased. It was concluded that the increase in the density of A. gossypii nymphs had positive and significant effects on reproductive parameters of H. variegata.


Acarologia ◽  
2017 ◽  
Vol 57 (3) ◽  
pp. 571-580
Author(s):  
Maryam Ghadim Mollaloo ◽  
Katayoon Kheradmand ◽  
Reza Sadeghi ◽  
Ali Aasghar Talebi

The sublethal effect of spiromesifen on life table parameters of Neoseiulus californicus McGregor (Acari: Phytoseiidae) was evaluated under laboratory conditions 25±1 °C, 65±5% RH and 16:8 (L:D) h. To take both sexes and the variable developmental rate among individuals into consideration, the raw data were analyzed based on the age stage, two sex life table. The estimated values of LC5, LC10 and LC15 for N. californicus are found to be 5.834, 9.529 and 13.267 ppm, respectively. The total preoviposition period of N. californicus treated with sublethal concentrations of spiromesifen was not significantly longer than for the control treatment. The minimum total fecundity was recorded for the LC15 concentration of spiromesifen (19.37 eggs/female) that was significantly different to the LC5 and control treatments. Compared with the control, the intrinsic rate of increase (r), finite rate of increase (λ), net reproductive rate (R0) and gross reproduction rates (GRR) of mites treated by the dose of the LC15 concentration, decreased significantly but the mean generation time (T) was not affected by this sublethal concentration. Our results indicated that increasing concentrations of spiromesifen had significant negative effects on life table parameters of N. californicus.These quantities should not be used in combination with N. californicus in integrated pest management programs in order to obtain optimal of biological control conclusions.


Insects ◽  
2021 ◽  
Vol 12 (7) ◽  
pp. 629
Author(s):  
Ya-Ling Wang ◽  
Qi-Nian Jin ◽  
Xiang-Ping Wang

Henosepilachna vigintioctopunctata (F.) is a serious pest of numerous solanaceous crops in many Asian countries. The purpose of this study was to clarify the effects of delayed mating on mating success, fecundity, fertility, pre-oviposition period, oviposition period, adult longevity, and population life table parameters (including net reproductive rate, intrinsic and finite rates of increase, doubling time, and mean generation time) of H. vigintioctopunctata. Beginning three days after emergence for both sexes, mating was delayed an additional 0, 2, 4, 6, or 8 days. We compared the data when mating was delayed for males only with the data when mating was similarly delayed for females only. Reproductive and life table parameters were calculated from the two data sets and compared. The results showed that the preoviposition and oviposition period of adults was significantly reduced by delayed mating, while the preoviposition period was not significantly different in adults mated at older ages. The mating success rate, fecundity, and proportion of hatching eggs decreased with increasing mating age. Longevity was not affected by the age at mating. Mating delay also affected the life table parameters of H. vigintioctopunctata, with a similar trend observed in the net reproductive rate and intrinsic and finite rates of increase, all of which decreased gradually as the number of delay days increased. The population doubling time increased with increases in mating age. The results also showed that delayed mating was an effective measure to consider in controlling H. vigintioctopunctata. It is hoped that our data will provide a scientific basis and contribute technical guidance for forecasting and integrated management of this pest.


Acarologia ◽  
2018 ◽  
Vol 58 (1) ◽  
pp. 52-61
Author(s):  
Samah Ben Chaaban ◽  
Brahim Chermiti ◽  
Serge Kreiter

The old world date mite Oligonychus afrasiaticus is an important spider mite pest of the date palms Phoenix dactylifera L. mostly in North Africa and the Middle East. A population of the predaceous mite Typhlodromus (Anthoseius) athenas has been recently found in Tunisia in association with a decrease of O. afrasiaticus densities. The objective of this paper was to assess the development and reproduction abilities of T. ( A.) athenas on O. afrasiaticus under laboratory conditions at two temperatures: 27 and 32 °C. The results obtained show that females of T. (A.) athenas develop in 5 days at 27 °C and 4.1 days at 32 °C. The mean fecundity of T. (A.) athenas was 32.1 and 23.2 eggs per female at 27 and 32 °C, respectively. Life table parameters were stimated: the net reproductive rate (Ro) 27.9 and 17.9 eggs/female, the intrinsic rate of increase (rm) 0.322 and 0,344 female/female/day and the mean generation time (T) 10.3 and 8.4 days at 27 and 32 °C, respectively. At both temperatures tested, T. (A.) athenas intrinsic rate of increase was greater than that of O. afrasiaticus (rm = 0.213 at 32 °C,against rm = 0.166 day1 at 27 °C). Typhlodromus (A.) athenas would be able to develop at a wide range of temperatures feeding on O. afrasiaticus and seems to be able to potentially control it.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Muhammad Rizwan ◽  
Bilal Atta ◽  
Muhammad Arshad ◽  
Rashad Rasool Khan ◽  
Asli Dageri ◽  
...  

AbstractThe non-persistent impact of biocontrol agents can be revealed for pest control when associated entomopathogenic fungi (EPFs) negatively affect the natural enemies. In this assay, impacts of Beauvaria bassiana (Balsamo) Vuillemin, and Metarhizium anisopliae (Metschnikoff) Sorokin were studied for their compatibility or side effects on life table parameters of an important generalist predator, Coccinella septempunctata L. The results indicated non-significant impacts of both EPFs on life table parameters of C. septempunctata. The development time (egg-adult) was not significantly different in control (69.79 days) and EPFs treated C. septempunctata (69.35–80.07 days). Both fungi did not induce any significant changes in the fecundity, adult pre-oviposition period (APOP), total preoviposition period (TPOP), and mean generation time (T) as compared to control treatment. Similarly, no difference in fecundity rate of C. septempunctata was observed after EPFs treatment (287.7–288.5) compared to control (290.0). The highest net reproductive rate (R0) occurred in control (87.05 offspring individual−1) and M. anisopliae (86.31 offspring individual−1) as compared to B. bassiana treated beetles (76.97 offspring individual−1). The age-specific fecundity curves indicated that the C. septempunctata had a similar fecundity rate in both EPFs treatments and control. This study demonstrates no significant side effects of B. bassiana and M. anispoliae on the performance and biology of C. septempunctata. Considering the compatibility of both EPFs with C. septempunctata, their combinations can be recommended in various integrated pest management programs.


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