scholarly journals Effects of sublethal concentrations and application concentration of SYP-9625 on Tetranychus cinnabarinus (Boisduval) and its natural enemy, Neoseiulus californicus (McGregor)

2018 ◽  
Author(s):  
Jingqi Ouyang ◽  
Yajing Tian ◽  
Chunxian Jiang ◽  
Qunfang Yang ◽  
Haijian Wang ◽  
...  

AbstractObjectiveExploring the effects of acaricides on predatory mites is crucial for the combination of biological and chemical control of pests. In this study, sublethal effects of the new acaricide SYP-9625 on Tetranychus cinnabarinus (Boisduval), effects of application concentration of SYP-9625 on the predatory mite Neoseiulus californicus (McGregor) and functional responses of N. californicus were assessed. The aim of the present study was to evaluate and explore the application of new acaricide SYP-9625 with natural enemy N. californicus.MethodAll the experiments were under laboratory conditions [25 ± 1 °C, 16:8 (L:D) h and 75 ± 5% RH] and based on an age-stage, two-sex life table. The sublethal concentrations against T. cinnabarinus, including LC10 (0.375 μg/mL) and LC30 (0.841 μg/mL) and the application concentration (100 μg/mL) of SYP-9625, were used to evaluate effects on population parameters of N. californicus.ResultT. cinnabarinus females treated with LC30 exhibited significantly reduced net reproductive rates (R0=11.02) of offspring compared to females treated with LC10 (R0=14.96) and untreated females (>R0=32.74). However, the intrinsic rate of increase (rm) and finite rate of increase (λ) of N. californicus indicated that the application concentration of SYP-9625 had no significant negative effect on treated N. californicus eggs (rm=0.277, λ=1.319) compared to the control (rm=0.292, λ=1.338). Additionally, the sublethal concentrations against T. cinnabarinus including LC10 and LC30 showed a dose-dependent mechanism on the predatory mite. SYP-9625 also stimulated the predatory capacity of N. californicus against immobile stages such as eggs and larvae.ConclusionIt is demonstrated that sublethal concentrations of SYP-9625 can inhibit population growth of T. cinnabarinus. And the sublethal concentrations and application concentration had little effect on the population growth of N. californicus. The two advantages showed great commercial potential of this new acaricide. Therefore, N. californicus can manage T. cinnabarinus populations effectively with appropriate SYP-9625 concentrations.

2019 ◽  
Vol 24 (8) ◽  
pp. 1512-1525
Author(s):  
Niloufar Sangak Sani Bozhgani1 ◽  
Katayoon Kheradmand ◽  
Aliasghar Talebi

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.


2014 ◽  
Vol 74 (3) ◽  
pp. 691-697 ◽  
Author(s):  
PP Marafeli ◽  
PR Reis ◽  
EC. da Silveira ◽  
GC Souza-Pimentel ◽  
MA. de Toledo

The predatory mite, Neoseiulus californicus(McGregor, 1954) (Acari: Phytoseiidae) is one of the principal natural enemies of tetranychid mites in several countries, promoting efficient control of those mites in several food and ornamental crops. Pest attacks such as that of the spider mite, Tetranychus urticaeKoch, 1836 (Acari: Tetranychidae), is one of the problems faced by farmers, especially in the greenhouse, due to the difficulty of its control with the use of chemicals because of the development of fast resistance making it hard to control it. The objective of this work was to study the life history of the predatory mite N. californicus as a contribution to its mass laboratory rearing, having castor bean plant [Ricinus communis L. (Euphorbiaceae)] pollen as food, for its subsequent use as a natural enemy of T. urticae on a cultivation of greenhouse rosebushes. The studies were carried out in the laboratory, at 25 ± 2°C of temperature, 70 ± 10% RH and a 14 hour photophase. The biological aspects and the fertility life table were appraised. Longevity of 32.9 days was verified for adult females and 40.4 days for males. The intrinsic rate of increase (rm) was 0.2 and the mean generation time (T) was 17.2 days. The population doubled every 4.1 days. The results obtained were similar to those in which the predatory mite N. californicus fed on T. urticae.


2017 ◽  
Vol 22 (10) ◽  
pp. 1748 ◽  
Author(s):  
Irena Međo ◽  
Bojan Stojnić ◽  
Dejan Marčić

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. 


Insects ◽  
2020 ◽  
Vol 11 (8) ◽  
pp. 491
Author(s):  
Muhammad Asim Rasheed ◽  
Muhammad Musa Khan ◽  
Muhammad Hafeez ◽  
Jing Zhao ◽  
Yasir Islam ◽  
...  

Except of pest control, insecticides have shown adverse effects on natural enemies as well. Thus, risk assessment of pesticides for biological control agents is critical for effective use in integrated pest management (IPM) schemes. In the present study, the lethal and sublethal effects of chlorpyrifos, a commonly used insecticide that may negatively affect biological control agents, were evaluated on a non-target predator, the Asian ladybeetle Harmonia axyridis. Previous studies have reported on lethal concentrations, but the effects of sublethal concentrations remain unclear. Lethal and sublethal concentrations of chlorpyrifos were applied to third instar larvae of H. axyridis, and different growth and developmental parameters were measured. Treatment with LC10 (4.62 mg a.i. L−1) significantly shortened the developmental period of third instar larvae, whereas it significantly prolonged those of fourth instar larvae and pupa. Treatment with LC30 (9.59 mg a.i. L−1) significantly increased the larval and pupal developmental period compared with that of the control, whereas feeding potential, female fecundity, and adult longevity significantly decreased after LC10 and LC30 treatment. The pre-oviposition period significantly increased compared with that of the control. Population growth parameters, the finite (λ) and intrinsic rate of increase (r) and the net reproductive rate (R0), decreased following exposure to sublethal concentrations of chlorpyrifos. According to the results, the use of chlorpyrifos in IPM schemes requires further research because even sublethal concentrations of this insecticide were harmful to H. axyridis population growth.


2020 ◽  
Vol 113 (6) ◽  
pp. 2713-2722
Author(s):  
Leila Mahmoodi ◽  
Fariba Mehrkhou ◽  
Nurper Guz ◽  
Maryam Forouzan ◽  
Remzi Atlihan

Abstract The cabbage aphid, Brevicoryne brassicae (L.), is one of the major insect pests of cole crops in Iran. In most instances outbreaks are normally kept under control by application of insecticides. In this study, the sublethal effects (LC30) of three insecticides, acetamiprid, buprofezin, and thiamethoxam-lambda cyhalothrin, (TLC) were evaluated on the population growth rate of the progeny of insecticide-treated cabbage aphid adults. The age-stage, two-sex life table method was used to analyze the collected data. The results indicated that the insecticide applications affected the duration of the preadult period, their survival, reproduction, life span/longevity, and consequently, the population growth rate of the F1 generation. The indicators of the greatest sublethal effects were noted in the progeny of the TLC-treated adults. These included the lowest net reproductive rate (R0), intrinsic rate of increase (r), finite rate of increase (λ), and the longest mean generation time (T). The highest values of r, λ, R, and the lowest value of T occurred in the control group followed by, in order, the acetamiprid and buprofezin groups. These research findings will be useful in the development and implementation of future aphid management programs.


Author(s):  
ChunXian Jiang ◽  
Lin Chen ◽  
TingTing Huang ◽  
Maryam Mumtaz ◽  
Qing Li

To evaluate the predation potential of Neoseiulus californicus (McGregor) reared on an artificial diet as a biological control agent for Tetranychus cinnabarinus (Boisduval), life table and functional response studies were performed. To identify alternative food sources for rearing N. californicus, we compared the nutritional values of the basal diet (composed of sucrose, yeast extract, honey, tryptone and egg yolk), meridic diet (add T. cinnabarinus on the basis of basal diet) and control (T. cinnabarinus). Further, the predation ability of N. californicus continuously reared for ten consecutive generations on a meridic diet to control T. cinnabarinus was assessed. The results showed that N. californicus fed the basal and meridic diets successfully completed development from eggs to adults, but they did not oviposit when fed the basal diet. The high fecundity (41.00 eggs per female) and intrinsic rate of increase (0.2357 d-1) recorded in the meridic diet group suggests that it is a suitable diet for N. californicus rearing. Additionally, a functional response (type II) was observed in N. californicus reared on the meridic diet. We found that when the predator was reared on the meridic diet, the estimated maximum attack rate (T/Th) associated with larvae was 58.67, which was only 13.94% lower than the control (68.17). The 10th generation of N. californicus did not lose the ability to capture and kill T. cinnabarinus when fed on meridic diet. In conclusion, N. californicus reared on the meridic diet containing T. cinnabarinus showed good predation ability; therefore, this diet may be beneficial for the mass production of N. californicus.


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.


2021 ◽  
Vol 26 (4) ◽  
pp. 788-800
Author(s):  
Gholamreza Tavakkoli Korghond ◽  
Najmeh Sahebzadeh ◽  
Hossein Allahyari ◽  
Sara Ramroodi

Crocus sativus L. (Iridaceae) known as saffron is the most commercially important medicinal food product in Iran and worldwide because of its significance for exporting commercial. However, the health of this plant is adversely threatened by abiotic and biotic stress. Bulb mite Rhizoglyphus robini Claparede (Acari: Acaridae) as abiotic stress is oligophagous and the main pest of tuber plants, commonly found in all the cultivated saffron producing areas could decrease saffron economic value. The mites tunnel through corms allowing the entry of fungal and bacterial pathogens. The widespread use of commercial pesticides in modern agriculture to protect crops from pests has caused significant public concern because of their side impacts on the environment and non-target species. Nanotechnology has been used in the production, processing, storage, packaging, and transport of agricultural products. Newly, oxide nanoparticles have been introduced as novel pesticides against pests and fertilizer. This study was conducted as an effective and environmentally-friendly method to control the growth of Rhizoglyphus robini. The lethal and sublethal effects of metal oxide nanoparticles (MNPs) including nano copper oxides (nano-CuO), nano magnesium oxide (nano-MgO), nano zinc oxide (nano-ZnO), nano titanium dioxide (nano-TiO2), and nano iron oxide (nano-Fe2O3) which their lethal concentrations ranged between 159.2 and 1036.4 mg L-1 were studied on Rhizoglyphus robini adult females. The contact effect of the tested MNPs was evaluated using the corm dip bioassay method. Assays showed that the contact toxicity of the nano-CuO treatment (229.1 mg L-1) was higher than other MNPs. To assess the sublethal effects of the MNPs, adult females were exposed to the LC25 concentration of MNPs, and life history and life-table parameters of the surviving Rhizoglyphus robini were investigated. The exposure to sublethal concentrations of the tested MNPs prolonged the egg incubation, larval period, and nymphal period significantly when compared to the control mites. Compared to other MNPs or control mite, nano-MgO and nano-TiO2 led to the longest duration of the total immature stages (11.32 and 11.32, respectively). The net reproductive rate (R0), the intrinsic rate of increase (rm), the finite rate of increase (λ), and the generation time (T) were significantly different between control and MNP treatments. The population exposed to ZnO-, MgO-, and TiO2-nanoformulations had a much lower rm value (0.164, 0.164, and 0.171 d-1, respectively) compared to the control population (0.231 d-1) and those exposed to Fe3O4- and CuO-nanoformulations (1.19 and 1.19 d-1, respectively). According to our findings, all tested MNPs, especially CuO-, ZnO-, and MgO-nano formulations, have a potential application for use in the management of Rhizoglyphus robini.


Insects ◽  
2020 ◽  
Vol 11 (2) ◽  
pp. 108 ◽  
Author(s):  
Byju N. Govindan ◽  
William D. Hutchison

Temperature is a critical single factor influencing insect population dynamics, and is foundational for improving our understanding of the phenology of invasive species adapting to new agroecosystems or in the process of range expansion. An age-stage, two-sex life table was therefore developed to analyze fundamental demographic features such as development, survival, and reproduction of a Minnesota-acclimated population of the invasive brown marmorated stink bug (Halyomorpha halys), in the north central USA. All salient life history parameters were estimated to better understand the population growth potential of H. halys at the current limit of its northern range in North America. We examined the effect of selected constant temperatures on immature development and survival (15–39 °C), adult reproduction and longevity (17–36 °C) of H. halys in the laboratory. The Minnesota population developed faster and survived at higher rates relative to a population that had previously established in Pennsylvania, USA. Mean generation time for the Minnesota population was minimized at 30 °C, while survival and fecundity were maximized at 27 and 23 °C, respectively. Given these findings, we assessed the effect of temperature on the intrinsic rate of increase ( r m ), the life table parameter that integrates the effects of temperature on development, survival, and reproduction. A Ratkowsky model predicted r m was maximized (0.0899) at 27.5 °C. We discuss the implications of our findings for understanding population growth rates for H. halys in the context of a warming climate, and potential to emerge as a serious crop pest in the Midwest U.S. region.


2017 ◽  
Vol 22 (1) ◽  
pp. 148 ◽  
Author(s):  
Ya Ying Li ◽  
Xiao Fan ◽  
Guo Hao Zhang ◽  
YI QING LIU ◽  
HAN QIU CHEN ◽  
...  

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.


Sign in / Sign up

Export Citation Format

Share Document