A promise extended future role of pyrethroids in agriculture

Can Indoxacarb be used to control pyrethroids in field corn 35?

The recent EPA registration of indoxacarb for adult rootworm control in field corn 35 provides a different mode of action that may be useful in WCR pyrethroid-resistance management programs.

Is WCR field-evolved resistance to pyrethroid insecticides in the US Western Corn Belt?

A low level of WCR field-evolved resistance to pyrethroid insecticides has been confirmed in the US western Corn Belt by laboratory dose-response bioassays.

Does dimethoate sensitivity shift in Pyrethroid-resistant WCR populations lead to practical resistance?

Results suggest that the observed shift in dimethoate susceptibility of pyrethroid-resistant WCR populations did not reach a level that would lead to “practical resistance” defined as field-evolved resistance that reduces field efficacy of a pesticide with practical consequences for pest control 57.


What is the significance level of the corn canopy spray deposition rate?

Corn canopy spray deposition rate and droplet size parameters reported from WSPs were subjected to analysis of variance in SAS 9.4 software (SAS Institute, Cary, NC) at significance level α = 0.05. The treatment design was a factorial arrangement with spray application rates (18.7 and 46.8 L/ha) and corn canopy position (Bottom, Middle, and Top) as factors in a randomized complete block experimental design (RCBD) where application lines were considered blocks.


What is the new class of pyrazoline insecticides?

McCann, S. F. et al. The discovery of indoxacarb: oxadiazines as a new class of pyrazoline-type insecticides. Pest Manag. Sci. 57, 153–164 (2001).


How effective are foliar insecticides?

Field efficacy of foliar insecticides depends on a combination of several factors such as target susceptibility, exposure, and application technique efficiency. For example, aerial application of insecticides can provide uneven coverage in the corn canopy resulting in insect sublethal exposure and reduced control 19. Some parameters such as spray carrier volumes, droplet size distribution, crop canopy, and environmental conditions often influence the coverage and uniformity of insecticide deposition which can confound field trial results 20, 21, 22, 23, 24. Carrying out consistent field trials to evaluate the efficacy of insecticide aerial applications on adult rootworms is even more challenging considering the potential interaction of population density and pest movement that may occur in the field 12, 25, 26, 27. Thus, methods that minimize factors influencing aerial application performance are necessary to evaluate the impact of WCR pyrethroid resistance on the efficacy of recommended foliar insecticides.


What is the WCR in corn?

Introduction. The western corn rootworm (WCR) Diabrotica virgifera virgifera LeConte (Coleoptera: Chr ysomelidae) is a major pest of corn Zea mays L. in the United States (US) and has adapted over time to many management tactics 1, 2.


What is the rootworm in corn?

The western corn rootworm ( Diabrotica virgifera virgifera LeConte) (WCR) is a major insect pest of corn ( Zea mays L.) in the United States (US) and is highly adaptable to multiple management tactics. A low level of WCR field-evolved resistance to pyrethroid insecticides has been confirmed in the US western Corn Belt by laboratory dose-response bioassays. Further investigation has identified detoxification enzymes as a potential part of the WCR resistance mechanism, which could affect the performance of insecticides that are structurally related to pyrethroids, such as organophosphates. Thus, the responses of pyrethroid-resistant and -susceptible WCR populations to the commonly used pyrethroid bifenthrin and organophosphate dimethoate were compared in active ingredient bioassays. Results revealed a relatively low level of WCR resistance to both active ingredients. Therefore, a simulated aerial application bioassay technique was developed to evaluate how the estimated resistance levels would affect performance of registered rates of formulated products. The simulated aerial application technique confirmed pyrethroid resistance to formulated rates of bifenthrin whereas formulated dimethoate provided optimal control. Results suggest that the relationship between levels of resistance observed in dose-response bioassays and actual efficacy of formulated product needs to be further explored to understand the practical implications of resistance.


What is the evidence of resistance to Cry34/35Ab1?

Gassmann, A. J. et al. Evidence of Resistance to Cry34/35Ab1 Corn by Western Corn Rootworm (Coleoptera: Chrysomelidae): Root Injury in the Field and Larval Survival in Plant-Based Bioassays. J. Econ. Entomol. 109, 1872–1880 (2016).


What is the simulated aerial application method?

The simulated aerial application method used was a conservative approach since it tested one model of spray deposition compatible with mid-canopy of corn plants of a given stage and beetles could not escape from treated surfaces. In the field there is a considerable interaction of environmental conditions, beetle movement behavior, and different levels of insecticide coverage within the corn canopy that could lead to differential adult exposure to insecticides. In fact, the spray deposition we collected in the field was fairly variable confirming the uneven canopy coverage previously observed for aerial applications 19. Variable levels of WCR exposure to insecticide applications could potentially lead to greater survival of WCR beetles in the field than measured in the aerial application simulation method, which may contribute to evolution of insecticide resistance and increase resistance levels measured in the lab over time 62, 63.


Abstract

Cypermethrin is a pyrethroid pesticide widely used to combat agricultural pests. However, little information is available about its toxicity in aquatic macroinvertebrates in the context of the Moroccan coastline.


Methods and Materials

Mussels M. galloprovincialis (average shell length = 45 ± 5 mm) were collected once a month at Cap Beddouza, Morocco (32°33′, 582N–09°15′, 813W) between January and March 2007 and transported to the laboratory within 3 h. The choice of Beddouza as a reference area was supported by previous chemical biomonitoring data (Banaoui et al.


Discussion

Cypermethrin reduced the valve closure in a time-dependent manner. With prolonged time of exposure, the effect of Cypermethrin became more evident and the increase in the concentration reduced the time to the first significant effect occurrence.


About this article

Ait Ayad, M., Ait Fdil, M. & Mouabad, A. Effects of Cypermethrin (Pyrethroid Insecticide) on the Valve Activity Behavior, Byssal Thread Formation, and Survival in Air of the Marine Mussel Mytilus galloprovincialis . Arch Environ Contam Toxicol 60, 462–470 (2011). https://doi.org/10.1007/s00244-010-9549-7


Abstract

Major methods for the biodegradation of organophosphate and pyrethroid pesticides are reviewed in this chapter. Although these methods are very promising, it is not easy to avoid fully the release of metabolites into the environment. Therefore, serious problems of soil, water and even foods contamination still exist.


Notes

NAS and WGB thanks, respectively, Fundação de Amparo a Pesquisa do Estado de São Paulo (FAPESP) and Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) for their scholarships. ALM Porto is grateful to CNPq and FAPESP for financial support.


About this chapter

Alvarenga N., Birolli W.G., Porto A.L.M. (2015) Biodegradation of Organophosphate and Pyrethroid Pesticides by Microorganims. In: Lichtfouse E., Schwarzbauer J., Robert D. (eds) Pollutants in Buildings, Water and Living Organisms. Environmental Chemistry for a Sustainable World, vol 7. Springer, Cham. https://doi.org/10.1007/978-3-319-19276-5_3


Where is prallethrin obtained?

Prallethrin Technical (95.53%) was obtained from M/S Shogun Organics Ltd. , Thane, India. Fifty post weaning Wistar rats (25 male and 25 female), aged 6–8 weeks with body weight of 145–200 g were used in the study. The temperature in the experimental animal room was maintained at 22 °C (±3 °C) with artificial lighting, the sequence being 12 h light, and 12 h dark. The animals were provided with pellet food (M/S Amrut feeds Ltd., Pune, India) and drinking water ad libitum. The experimental animals were housed in conventional polypropylene cages in small groups (five each) of same sex. The rats were randomly assigned to control and treatment groups. The animals were allowed to acclimatize to the laboratory conditions for 5 days prior to the start of study.


What are biochemical parameters?

Moreover, a combination of some common biochemical parameters provide better information from pattern recognition, e.g. plasma enzymes like AST, ALT and ALP for hepatotoxicity and urea and creatinine for glomerular function [10].


Is prallethrin toxic to humans?

Although the data cannot be extrapolated directly from rats to human being, but it may be concluded that Prallethrin use may cause hazardous effects in various levels to non-target species.


Abstract

Climate change factors such as rainfall, heat waves, rising temperatures and flooding have positively impacted insect vector population. This scenario poses considerable demand on chemical control. This study was carried out with the specific aim to examine the influence of changes in temperature and exposure time of C.


Introduction

Climate change in the tropics have resulted in decreased precipitation, shift in seasonal rainfall, heat waves, rising temperatures and flooding. These factors have triggered the population of water borne insect vectors and diseases they transmit.


Methodology

Bait containing mixture of water and yeast was used as attractant for the adult C. quinquefasciatus mosquitoes to lay eggs in the insectarium at Federal University of Technology Akure (70.5′N and 50.15′E).


Bioassays

Trial dose-mortality response were carried out to determine the serial dilution concentrations. 1 ppm stock solution of the Cypermethrin (Cypertex 10%EC) was prepared using acetone as solvent. And serial dilutions of concentrations of 1250 ppm, 625 ppm, 310 ppm, 31 ppm, 16 ppm were prepared.


Discussion

Climate change poses a threat to the control of insect pests and disease infestations.


Author’s contributions

AKL conceived the research, analysed the data, wrote and proofread the scripts, ARA performed the experiments, analysed the data under the supervision of AKL while EJA proofread the script.


Acknowledgment

We are grateful to Mr Olorunfemi O. Sunday (PhD student in Applied Entomology) for his contributions.

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