scholarly journals Evaluation of the sublethal effect of tetrachlorantraniliprole on Spodoptera exigua and its potential toxicity to two non-target organisms

PLoS ONE ◽  
2020 ◽  
Vol 15 (11) ◽  
pp. e0242052
Author(s):  
Haiyuan Teng ◽  
Yongda Yuan ◽  
Tianshu Zhang ◽  
Xiaoli Chang ◽  
Dongsheng Wang

Tetrachlorantraniliprole (TCAP) is a novel anthranilic diamide insecticide that specifically targets the ryanodine receptors of lepidopteran insect species with excellent insecticidal activity. Previous studies have reported the sublethal effects of multiple diamides on several lepidopteran species, whereas the sublethal and non-target effects of TCAP remain largely unknown. We assessed the sublethal effects of TCAP on Spodoptera exigua. We also investigated the effects of TCAP on non-target Harmonia axyridis and Eisenia fetida, S. exigua was more sensitive to TCAP than to chlorantraniliprole, as the LC50 (10.371 μg L-1 at 72 h) of TCAP was relatively lower. Compared with those of the control, sublethal concentrations of TCAP (LC10 and LC30) not only prolonged the duration of the larval and pupal stages as well as the mean generation time but also reduced certain population parameters. On the other hand, TCAP exposure, even at the highest concentration, did not induce toxic effects in H. axyridis ladybugs (1st instar larvae and adults) or E. fetida earthworms. Taken together, our results suggest that TCAP can be used as a novel and promising component of the integrated pest management (IPM) program against S. exigua due to its robust target effects and negligible non-target risks.

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 3 (1) ◽  
pp. 14-32
Author(s):  
AS Lemuel ◽  
HB Hassan ◽  
JK Makpo ◽  
AA Abdulmalik ◽  
NC Andrew

This study was undertaken to evaluate the sublethal effects of the water-soluble fractions of virgin diesel oil on some physiological parameters of C. gariepinus juveniles. The mean weight of C.gariepinus Juveniles weight of 1.61±1.86g, total length of 9.5±10.5cm and standard length of 11.0±12.5cm were exposed to sublethal concentrations of 0.58 ml/L, 0.29 ml/L, 0.14 ml/L, 0.07 ml/L, 0.04 ml/L and control 0.00 ml/L. There were significant differences at (P<0.05) on the different levels of sublethal concentrations. The tissues include; gills, liver and intestine. The alterations considered include; the gills; inflammation, hyperplasia, fusion, lamella aneurism, epithelial lifting, abrasion and necrosis, in the liver, there was lesions, and inflammation, and also alterations of the intestine were mainly sloughing of the intestinal villi and intestinal mucosa. It was concluded that contamination of water-soluble fractions of virgin diesel oil in any water body or aquatic environment can induce several histopathological alterations in the tissues of Clarias gariepinus juvenile.


2020 ◽  
Vol 25 (5) ◽  
pp. 906-917
Author(s):  
Marzieh Alinejad ◽  
Katayoon Kheradmand ◽  
Yaghoub Fathipour

Knowledge of the impact of acaricides on predatory mites is crucial for integrated pest management (IPM) programs. The sublethal effect of propargite was assessed against the subsequent generation of treated Amblyseius swirskii Athias-Henriot (Acari: Phytoseiidae) fed on Tetranychus urticae Koch (Acari: Tetranychidae) under laboratory conditions [26 ± 1 ̊C, 70 ± 3 % RH and 16:8 (L:D) h]. A leaf disc bioassay was employed to assess the sublethal concentrations (LC10, LC20, and LC30) of propargite (Omite® 57% EC, MAHAN, Iran) on A. swirskii. The results revealed that sublethal concentrations of propargite significantly affected the total life span and longevity of the treated females of A. swirskii. Reproductive and total fecundity of the subsequent generation were also affected by sublethal concentrations. All concentrations caused a significant reduction in oviposition days, compared to the control. The intrinsic rates of increase (r) of A. swirskii treated with sublethal concentrations of propargite and distilled water were 0.126, 0.122, 0.115, and 0.129 d-1, respectively. Our findings revealed that propargite had no significant effect on life table parameters of treated mites in comparison to the control. Sublethal effects of propargite and its impact on A. swirskii are discussed.


2019 ◽  
Vol 24 (5) ◽  
pp. 814
Author(s):  
Mohammad Shahbaz ◽  
Mehdi Khoobdel ◽  
Mohammad Khanjani ◽  
Asghar Hosseininia ◽  
Saeid Javadi Khederi

The whitefly, Aleuroclava jasmini (Takahashi) (Hemiptera: Aleyrodidae), is an important pest on paper mulberry Broussonetia papyrifera (L.) Vent. (Moraceae) plants in green spaces of Tehran, Iran. The predator mite Amblyseius swirskii Athias-Henriot is one of the most common species found in paper mulberry landscape and it is a major biological control agent of this pest. Knowledge of the impact of insecticides on predatory mites is crucial for integrated management programs of this whitefly. This study assessed, under laboratory conditions, the sublethal effect of acetamiprid on the life table parameters of A. swirskii fed on A. jasmini. The sublethal concentrations LC10, LC20 and LC30 were obtained based on a dose-effect test. Exposure to the sublethal concentrations of acetamiprid had significant effects on the total immature periods of both males and females. The total fecundity and oviposition period decreased with an increase in concentration. The estimated life table parameters indicated that sublethal concentrations of acetamiprid caused greater reduction in r, λ and R0 of A. swirskii compared to the control. Therefore, the use of acetamiprid to control of A. jasmini may have serious implications for integrated pest management programs that aimed at exploiting A. swirskii biological control in paper mulberry landscape.


Insects ◽  
2021 ◽  
Vol 12 (2) ◽  
pp. 109
Author(s):  
Norazila Yusoff ◽  
Idris Abd Ghani ◽  
Nurul Wahida Othman ◽  
Wan Mohd Aizat ◽  
Maizom Hassan

The diamondback moth, Plutella xylostella (L.) (Lepidoptera: Plutellidae), is the most important pest of cruciferous vegetables worldwide. In this study, we evaluated the properties of selected farnesyl derivative compounds against P. xylostella. The toxicity and sublethal concentration (LC50) of farnesyl acetate, farnesyl acetone, farnesyl bromide, farnesyl chloride, and hexahydrofarnesyl acetone were investigated for 96 h. The leaf-dip bioassays showed that farnesyl acetate had a high level of toxicity against P. xylostella compared to other tested farnesyl derivatives. The LC50 value was 56.41 mg/L on the second-instar larvae of P. xylostella. Then, the sublethal effects of farnesyl acetate on biological parameters of P. xylostella were assessed. Compared to the control group, the sublethal concentration of farnesyl acetate decreased pupation and emergence rates, pupal weight, fecundity, egg hatching rate, female ratio, and oviposition period. Furthermore, the developmental time of P. xylostella was extended after being exposed to farnesyl acetate. Moreover, the application of farnesyl acetate on P. xylostella induced morphogenetic abnormalities in larval–pupal intermediates, adults that emerged with twisted wings, or complete adults that could not emerge from the cocoon. These results suggested that farnesyl acetate was highly effective against P. xylostella. The sublethal concentration of farnesyl acetate could reduce the population of P. xylostella by increasing abnormal pupal and adults, and by delaying its development period.


2020 ◽  
Vol 44 (1) ◽  
Author(s):  
El-Sayed Mokbel ◽  
Amal Huesien

Abstract Background The cotton leafworm, Spodoptera littoralis (Boisd.), is a serious economic pest in Egypt. Pest control depends mainly on chemical control with several pesticides include conventional and modern insecticides. Comprehensive analysis of pesticides impacts needs to investigate sublethal effects in addition to lethal effect. Results In the current study, the leaf-dip bioassay method was used to evaluate emamectin benzoate (EMB) sublethal concentrations. Results showed that EMB proved high toxicity against S. littorals with LC50 value of 0.019 mg liter−1. Life table analysis showed that treatments with LC5 and LC15 prolonged larval period, mean longevity of males and females, mean generation time (T), doubling time (DT), adult preovipositional period (APOP), and total preovipositional period (TPOP) compared with control. On the contrary, net reproduction rates (R0), intrinsic rates of increase (r), finite rate (λ), fecundity, gross reproductive rate (GRR), and relative fitness were decreased compared to control. Conclusions The current study clarified that sublethal concentrations of EMB induce adverse effects and suppress the population growth of S. littorals. Our results would be useful to assess the overall effects of EMB on S. littorals and can contribute effectively in pest management.


Author(s):  
Mayara Fernandes dos Santos ◽  
Paulo Roberto Ramalho Silva ◽  
Marcus Eugênio O. Briozo ◽  
Joesley Frazão Silva ◽  
Luiz Carlos de Melo Junior ◽  
...  

The objective of this study is to evaluate the toxicity, repellency, and the ovicidal, residual, and sublethal effects of different neem-based commercial formulations on the red mite Tetranychus neocaledonicus André (1933) reared in the laboratory on lima bean (Phaseolus lunatus L.). To evaluate the toxicity on adult females of T. neocaledonicus, different concentrations of Natural Neem® (NN), Off-Neem® (ON), Nim-I-GO® (NG), and Azamax® (AZ) were defined from preliminary tests. The mortality and toxicity ratio were evaluated 48 h after application of the lethal concentrations (LC50s and LC95s). The repellent effect was verified through a two-choice test. The concentration used was the LC50 of the products calculated in the toxicity test. The number of mites attracted, the repellency index (RI), and the percentage of repellency of each product were calculated. The ovicidal effect after application of the LC50s and LC95s of each product and egg viability were observed. To evaluate the residual efficiency, the plants were sprayed with LC50 and LC95 of the products and the leaves were subsequently harvested at 24, 48, and 96h after the application of the products to evaluate mortality and oviposition reduction (PR - percentage of reduction). The sublethal effects were evaluated by applying the LC30 of the products (AZ, NG) to newly emerged females, whose survival and oviposition were evaluated daily. The determined LC50s were 0.39; 0.48; 0.68; and 1.39% for AZ, ON, NN, and NG, respectively. Considering the LC50, AZ was the most toxic product followed by ON, whereas the established LC95s were 2.20; 3.74; 6.10; and 7.98% for NN, ON, AZ, and NG, respectively. All tested products were classified as repellents for adult females of T. neocaledonicus. The eggs of T. neocaledonicus treated with the LC95s of the products had their viabilities inhibited. However, when using the LC50s, NN provided the lowest viability (8.0%), being considered the most toxic for eggs. The products presented reduced residual effect probably due to their rapid degradation. The mites treated with sublethal concentrations showed an average survival in days of 25.43, 28.35, and 29.20 for the treatments with Azamax®, control (untreated), and Nim-I-GO®, respectively. Relatively high oviposition rates in the first weeks decreased until the end of their life cycle. The life history of T. neocaledonicus is affected by sublethal concentrations of neem-based products. It was concluded that the tested products demonstrated acaricidal potential in the control of T. neocaledonicus on P. lunatus, presenting toxicity and repellent and ovicidal effect, although residual and sublethal effects were less significant.


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.


2017 ◽  
Vol 91 ◽  
pp. 108-113 ◽  
Author(s):  
Ran Wang ◽  
Wei Zhang ◽  
Wunan Che ◽  
Cheng Qu ◽  
Fengqi Li ◽  
...  

1999 ◽  
Vol 113 (2) ◽  
pp. 229-238 ◽  
Author(s):  
Guillermo J. Pérez ◽  
Adrian D. Bonev ◽  
Joseph B. Patlak ◽  
Mark T. Nelson

The relationship between Ca2+ release (“Ca2+ sparks”) through ryanodine-sensitive Ca2+ release channels in the sarcoplasmic reticulum and KCa channels was examined in smooth muscle cells from rat cerebral arteries. Whole cell potassium currents at physiological membrane potentials (−40 mV) and intracellular Ca2+ were measured simultaneously, using the perforated patch clamp technique and a laser two-dimensional (x–y) scanning confocal microscope and the fluorescent Ca2+ indicator, fluo-3. Virtually all (96%) detectable Ca2+ sparks were associated with the activation of a spontaneous transient outward current (STOC) through KCa channels. A small number of sparks (5 of 128) were associated with currents smaller than 6 pA (mean amplitude, 4.7 pA, at −40 mV). Approximately 41% of STOCs occurred without a detectable Ca2+ spark. The amplitudes of the Ca2+ sparks correlated with the amplitudes of the STOCs (regression coefficient 0.8; P &lt; 0.05). The half time of decay of Ca2+ sparks (56 ms) was longer than the associated STOCs (9 ms). The mean amplitude of the STOCs, which were associated with Ca2+ sparks, was 33 pA at −40 mV. The mean amplitude of the “sparkless” STOCs was smaller, 16 pA. The very significant increase in KCa channel open probability (&gt;104-fold) during a Ca2+ spark is consistent with local Ca2+ during a spark being in the order of 1–100 μM. Therefore, the increase in fractional fluorescence (F/Fo) measured during a Ca2+ spark (mean 2.04 F/Fo or ∼310 nM Ca2+) appears to significantly underestimate the local Ca2+ that activates KCa channels. These results indicate that the majority of ryanodine receptors that cause Ca2+ sparks are functionally coupled to KCa channels in the surface membrane, providing direct support for the idea that Ca2+ sparks cause STOCs.


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