Biological responses of Tetranychus urticae to five pepper cultivars at two phenological stages of host plants

2021 ◽  
Author(s):  
Samira Khodayari ◽  
Maryam Hashemian Shalilvand
Keyword(s):  
Tetranychus Urticae ◽  
Host Plants ◽  
Intrinsic Rate ◽  
Intrinsic Rate Of Increase ◽  
Adult Longevity ◽  
Phenological Stages ◽  
Rate Of Increase ◽  
Significant Difference ◽  
Before And After ◽  
Important Pest

The two-spotted spider mite, Tetranychus urticae Koch (Acari: Tetranychidae) is an important pest of pepper (Capsicum annuum L.). Control of this pest is usually dependent on chemical pesticides. The use of resistant plant cultivars in conjugation with other control tactics generates more effective and long lasting results in management of many pests. In this study we used two-sex life table to evaluate the performance of T. urticae on five pepper cultivars (11983, ES4, Hashemi, Mahali and USL) before and after blooming of host plants. The results showed that the immature time, adult longevity and fecundity differed significantly among cultivars. Before blooming on 11983, the values for the intrinsic rate of increase (r) and the finite rate of increase (λ) were 0.0645 and 1.066 day-1 respectively, which were significantly the lowest; the highest r and λ values was recorded on ES4 which were 0.1347 and 1.144 day-1 respectively. After blooming there was no significant difference in these values among cultivars except for Mahali in which these values were significantly the highest (0.0751 and 1.078 day-1 respectively). Comparing between the phenological stages of host plants (before and after blooming) indicated that after blooming all of the tested pepper cultivars were more resistant to T. urticae. In summary, among the different cultivars tested, the most suitable was ES4 and the least suitable was 11983 before blooming of host plants. After blooming the suitability of host plants changed and decreased significantly.

The performance of Tetranychus urticae on five melon cultivars is correlated with leaf thickness

2019 ◽  
Vol 24 (4) ◽  
pp. 645
Author(s):  
Dandan Xu ◽  
Ke Wang ◽  
Yating Zhang ◽  
Huaisong Wang ◽  
Qingjun Wu ◽  
...  
Keyword(s):  
Tetranychus Urticae ◽  
Spider Mite ◽  
Stomatal Density ◽  
Morphological Characteristics ◽  
Intrinsic Rate ◽  
Leaf Thickness ◽  
Intrinsic Rate Of Increase ◽  
Adult Longevity ◽  
Trichome Density ◽  
Rate Of Increase

The two-spotted spider mite, Tetranychus urticae Koch (Acari: Tetranychidae), is an important pest of melons. In this laboratory study, we used two-sex life table to evaluate the performance of T. urticae on five melon cultivars (IVF28, IVF118, IVF168, IVF437, and Yangjiaomi). We also evaluated the correlation between mite population growth and morphological characteristics of leaves. The results showed that the total immature time, adult longevity, total longevity, and fecundity of the spider mite differed among the cultivars. On IVF28, the values for the intrinsic rate of increase (r) and the finite rate of increase (λ) were 0.1638 d-1 and 1.1178 d-1, respectively, which were significantly lower than the values on IVF168, IVF118, or Yangjiaomi. Values for r and λ tended to be highest on IVF168. In addition, r values for T. urticae were not correlated with trichome density or stomatal density but were negatively correlated with melon leaf thickness. In summary, the different melon cultivars exhibited distinct levels of resistance to T. urticae and the IVF28 cultivar was considered the least favored for the growth and reproduction of T. urticae mites, and such differences of mite performance might be related to the leaf thickness, instead of trichome density or stomatal density.

Biological responses of Tetranychus urticae (Acari: Tetranychidae) to sub-lethal concentrations of the entomopathogenic fungus Beauveria bassiana

2021 ◽  
pp. 1-8
Author(s):  
Katayoon Kheradmand ◽  
Mahmoud Heidari ◽  
Amin Sedaratian-Jahromi ◽  
Reza Talaei-Hassanloui ◽  
Mohammadreza Havasi
Keyword(s):  
Tetranychus Urticae ◽  
Beauveria Bassiana ◽  
Intrinsic Rate ◽  
Reproductive Rate ◽  
Intrinsic Rate Of Increase ◽  
Adult Longevity ◽  
Net Reproductive Rate ◽  
Targeted Interventions ◽  
Worldwide Distribution ◽  
Rate Of Increase

Abstract Tetranychus urticae (Acari: Tetranychidae) is one of the most important pests of agricultural crops with worldwide distribution causing considerable damage to different products. Application of chemical acaricides is one of the most important strategies used for the control of this pest. Entomopathogenic fungi, however, have been proposed as alternative control agents. In this study, sub-lethal effects (LC10 = 6.76 × 102, LC20 = 8.74 × 103, and LC30 = 55.38 × 103 conidia ml−1) of Beauveria bassiana strain TV on the life table parameters of T. urticae were evaluated under laboratory conditions. The results demonstrated that by increasing the concentration, a significant decline was observed in adult longevity of both male and female individuals. Total fecundity of T. urticae was calculated as 45.16, 36.28, 23.98, and 18.21 eggs in control, LC10, LC20, and LC30 treatments, respectively. Sub-lethal concentrations drastically affected the population parameters of this mite pest. The intrinsic rate of increase (r) ranged from 0.1983 to 0.1688 day−1 for the mites treated with distilled water and LC20 treatments, respectively. The net reproductive rate (R0) was affected by the sub-lethal concentrations (lower value at LC30 concentration: 11.19 offspring/individual). Considering the detrimental effects of B. bassiana on some biological parameters of T. urticae, it can be concluded that this product can be used to develop targeted interventions aimed at integrated pest management of this pest.

scholarly journals Sublethal effects of bifenazate on life history and population parameters of Tetranychus urticae (Acari: Tetranychidae)

2017 ◽  
Vol 22 (1) ◽  
pp. 148 ◽  
Author(s):  
Ya Ying Li ◽  
Xiao Fan ◽  
Guo Hao Zhang ◽  
YI QING LIU ◽  
HAN QIU CHEN ◽  
...  
Keyword(s):  
Life History ◽  
Tetranychus Urticae ◽  
Sublethal Effects ◽  
Sublethal Effect ◽  
Intrinsic Rate ◽  
Lethal Effect ◽  
Intrinsic Rate Of Increase ◽  
Population Parameters ◽  
Rate Of Increase ◽  
Two Spotted Spider Mite

Traditional estimating only by measuring the lethal effect of acaricides may underestimate the total effects of acaricides on the pest mites. In order to investigate the sublethal effect of bifenazate on life history and population parameters of the two-spotted spider mite, Tetranychus urticae Koch, the newly emerged females were treated with two lethal concentrations of bifenazate: LC10 (4.92 μg/mL) and LC20 (8.77 μg/mL). Subsequently, the development and fecundity of the progeny generations were observed. Compared to the control, exposure to the 10% lethal concentrations (LC10) and LC20 of bifenazate severely affected the parental generation of T. urticae, including survival rate (reduced 9% and 13%), oviposition period (reduced 77.6% and 83.1%), fecundity per female (decreased 89.2% and 76.9%) and longevity (decreased 79.2% and 83.1%). Besides, the population parameters of the progeny generation from the treated females were also investigated. The results showed that the progeny generation had lower intrinsic rate of increase (rm) and finite rate of increase (λ), longer mean generation time (Tc) compared to the control. The results suggested that the sublethal effects of bifenazate on population growth of T. urticae were significant, and the results of this study could be used as a guide for the rational use of bifenazate in the field for better managing pest mites.

The effects of Spiromesifen on life history traits and demographic parameters of predatory mite Neoseiulus californicus (Acari: Phytoseiidae) and its prey Tetranychus urticae Koch (Acari: Tetranychidae)

2019 ◽  
Vol 24 (8) ◽  
pp. 1512-1525
Author(s):  
Niloufar Sangak Sani Bozhgani1 ◽  
Katayoon Kheradmand ◽  
Aliasghar Talebi
Keyword(s):  
Life History ◽  
Tetranychus Urticae ◽  
Life History Traits ◽  
Sublethal Effects ◽  
Predatory Mite ◽  
Neoseiulus Californicus ◽  
Intrinsic Rate Of Increase ◽  
Adult Longevity ◽  
Demographic Parameters ◽  
Rate Of Increase

Estimating sublethal effects of acaricides on phytoseiid mites and their prey as a reliable approach in predicting the acaricides impacts is mandatory for IPM programs. The aim of this study was to evaluate the effects of spiromesifen on life history traits and demographic parameters of the offspring of Neoseiulus californicus and Tetranychus urticae under laboratory conditions [25 ± 2ºC, 70 ± 5% RH and 16:8 (L:D) h]. The experiments were conducted based on the leaf-dip technique. The crude data were analysed based on age-stage, two-sex life table analysis. The pre-adult and adult longevity of both sexes significantly reduced for N. califonicus and T. urticae with the concentration enhancing from LC20 to LC35. In addition, the oviposition period for both species significantly decreased as a consequence of treatment with LC25 and LC35 of spiromesifen. The minimal values of the total fecundity for N. califonicus and T. urticae were 16.58 and 19.35 (offspring/individual), respectively, which was related to LC35 concentration. Further, the lowest values of R0 and GRR of N. califonicus and its prey were 48.88 and 31.14 (offspring/individual) in LC35, respectively. However, the intrinsic rate of increase (r) and finite rate of increase (λ) were not significantly influenced by sublethal concentration in N. californicus while the r and λ were significantly reduced in T. urticae treated by LC20, LC25 and LC35. Therefore, spiromesifen could profoundly decrease the population growth rate of T. urticae but can not be considered as a compatible acaricide with N. califonicus because of its negative effect on the longevity, total lifespan, and reproductive periods and should not be used with this predatory mite in integrated pest management programs.

Temperature-dependent development and life table parameters of Schizotetranychus smirnovi (Acari: Tetranychidae) on Almond

2020 ◽  
Vol 25 (8) ◽  
pp. 1373-1383
Author(s):  
Zarir Saeidi ◽  
Alireza Nemati ◽  
Elham Riahi
Keyword(s):  
Life Table ◽  
Intrinsic Rate ◽  
Mite Species ◽  
Reproductive Rate ◽  
Intrinsic Rate Of Increase ◽  
Adult Longevity ◽  
Offspring Production ◽  
Temperature Regimes ◽  
Rate Of Increase ◽  
Different Temperatures

In the current study, development, reproduction, and longevity of Schizotetranychus smirnovi Wainstein concerning seven different temperatures including 13±1, 15±1, 20± 1, 25±1, 27±1, 30 ±1 and 35 ±1°C, relative humidity 50 ± 10 % and a photoperiod of 14:10 (L:D) h. were investigated. Due to mite inability to settle on leaf disk, almond young branches were used for conducting life table experiments. Our results indicated that higher and lower temperatures caused a steeper decline in survivorship. The highest survival rate was observed at 25 and 27°C. The mean total development time was significantly decreased with increasing the temperatures; while adult longevity for both female and males significantly decreased. Furthermore, offspring production did not occur at 35°C. The highest values of the intrinsic rate of increase (r) and finite rate of increase (λ) were 0.2563 and 1.2922 d-1 at 27°C, while their lowest values were obtained at 13°C. Again high temperature (30°C) caused a decline in both the reproductive rate and growth rate of this mite species. The longest mean generation time (T) (58.55 d) was at 13 °C and it declined significantly with increasing temperature. The most striking result emerging from our data is that 27°C is the most desirable temperature for not only development but also the reproduction of S. smirnovi. Finally, our obtained information provides a better understanding of the life history of S. smirnovi and its ability to survive and reproduce under different temperature regimes which can be used in the management of this pest.

Acaricidal activity and sublethal effects of the microbial pesticide spinosad on Tetranychus urticae (Acari: Tetranychidae)

2017 ◽  
Vol 22 (10) ◽  
pp. 1748 ◽  
Author(s):  
Irena Međo ◽  
Bojan Stojnić ◽  
Dejan Marčić
Keyword(s):  
Population Growth ◽  
Tetranychus Urticae ◽  
Sublethal Effects ◽  
Intrinsic Rate ◽  
Intrinsic Rate Of Increase ◽  
Instantaneous Rate ◽  
Leaf Discs ◽  
Rate Of Increase ◽  
Female Longevity ◽  
Microbial Pesticide

Laboratory bioassays were conducted to evaluate the toxicity of the microbial pesticide spinosad to different life stages of the two-spotted spider mite, Tetranychus urticae Koch, as well as its sublethal effects on reproduction and population growth of this important mite pest. The biopesticide was applied to bean primary leaves or leaf discs carrying spider mites using a Potter spray tower (2.7 mg/cm2 aqueous deposit). The following LC50 and LC90 (mg/L) estimates for motile stages were obtained in acute toxicity bioassays: 27.52 and 116.72 (larvae), 36.55 and 136.20 (protonymphs), 82.76 and 721.28 (female deutonymphs), and 61.47 and 457.21 (adult females). Spinosad showed no significant ovicidal action: toxic effect observed after spraying eggs (LC50 = 105.78 mg/L, LC90 = 596.95 mg/L) was the result of its residual action on larvae that hatched from the treated eggs. The effects of spinosad on life history traits and population growth of adult female survivors from treatments with 240, 120 and 60 mg/L were evaluated in two successive 7-day bioassays on untreated leaf discs. In the first bioassay, females that survived treatments as 24 h old eggs and completed their juvenile development on treated leaves had significantly lower gross fecundity, net fecundity and instantaneous rate of increase (ri) but the reduction was merely 4–6%, 9–11%, and 2–3%, respectively. Female longevity was significantly reduced (approximately by half a day) only after treatment with 240 mg/L. In the second bioassay, in which females were treated during their pre-ovipositional period, the treatments with 240 and 120 mg/L significantly reduced their gross fecundity (16–17%), net fecundity (28–31%), ri values (8–9%) and female longevity (approximately by one day). Spinosad effects on the intrinsic rate of increase (rm) and other demographic parameters were evaluated in two successive bioassays in which life tables were constructed for females that survived treatment with 120 mg/L at the egg stage (first demographic bioassay) or pre-ovipositional period (second demographic bioassay). In the first bioassay, the intrinsic rate of increase was significantly higher in treated (rm = 0.278) than control mites (rm = 0.267) as a result of higher net fertility at the beginning of reproduction of treated females. In the second bioassay, treated females had significantly lower rm than control females (0.254 and 0.283, respectively). The results obtained in this study indicate that spinosad, applied against insect pests (at field relevant rates of 60–240 mg/L), could eliminate a part of T. urticae population as well, but survivors would retain a significant potential for population recovery. 

scholarly journals Age Stage Two-Sex Life Table Reveals Sublethal Effects of Some Herbal and Chemical Insecticides on Adults ofBemisia tabaci(Hem.: Aleyrodidae)

2014 ◽  
Vol 2014 ◽  
pp. 1-9 ◽  
Author(s):  
Fatemeh Jafarbeigi ◽  
Mohammad Amin Samih ◽  
Mehdi Zarabi ◽  
Saeideh Esmaeily
Keyword(s):  
Life Table ◽  
Sublethal Effects ◽  
Intrinsic Rate ◽  
Reproductive Rate ◽  
Intrinsic Rate Of Increase ◽  
Calotropis Procera ◽  
Thymus Vulgaris ◽  
Net Reproductive Rate ◽  
Rate Of Increase ◽  
Important Pest

The sweetpotato whitefly,Bemisia tabaci(Genn.) (Hem.: Aleyrodidae), is an important pest of agriculture in subtropical and tropical areas. In this study, we used the age-stage two-sex life table to evaluate the sublethal effects of the herbal extracts taken fromFumaria parvifloraLam. (Fumariaceae),Teucrium poliumL. (Lamiaceae),Calotropis procera(Willd.) R. Br. (Asclepiadaceae), andThymus vulgarisL. (Lamiaceae) as well as the two commercial synthetic insecticides, pymetrozin and neemarin. The whiteflies were exposed to each insecticide using leaf-dip method. Analysis of life table parameters revealed significant differences (P≤0.05) in the net reproductive rate (R0,NRR), intrinsic rate of increase (rm), and finite rate of increase (λ) among different insecticides. The lowest values of the three population parameters,R0,r, andλ, were observed on whiteflies treated with pymetrozin (2.455, 0.036, and 1.036),T. polium(2.828, 0.044, and 1.045), and neemarin (2.998, 0.046, and 1.047), respectively. Results of this study highlights the satisfactory insecticidal effects of the extract taken fromT. poliumonB. tabaci, which is comparable to the two commonly used synthetic insecticides.

Group-rearing did not affect the life table and predation rate of Phytoseiulus persimilis (Acari: Phytoseiidae) fed on Tetranychus urticae

2017 ◽  
Vol 22 (10) ◽  
pp. 1698 ◽  
Author(s):  
Sahar Saemi ◽  
Hasan Rahmani ◽  
Aurang Kavosi ◽  
Hsin Chi
Keyword(s):  
Life Table ◽  
Tetranychus Urticae ◽  
Phytoseiulus Persimilis ◽  
Intrinsic Rate ◽  
Predation Rate ◽  
Reproductive Rate ◽  
Intrinsic Rate Of Increase ◽  
Net Reproductive Rate ◽  
Rate Of Increase ◽  
Negative Effect

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. 

Effect of induced resistance in bean plants on Tetranychus urticae life table parameters

2018 ◽  
Vol 23 (8) ◽  
pp. 1627
Author(s):  
Atefeh Dahmardeh ◽  
Malihe Latifi ◽  
Rohollah Saberi Riseh
Keyword(s):  
Life Table ◽  
Tetranychus Urticae ◽  
Intrinsic Rate ◽  
Reproductive Rate ◽  
Intrinsic Rate Of Increase ◽  
Life Table Parameters ◽  
Acid Complex ◽  
Net Reproductive Rate ◽  
Bean Plants ◽  
Rate Of Increase

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.

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