Field Evaluation of Cypermethrin, Imidacloprid, Teflubenzuron and Emamectin Benzoate against Pests of Quinoa (Chenopodium quinoa Willd.) and Their Side Effects on Non-Target Species.

Luis Cruces,Patrick De Clercq,Eduardo De La Peña

doi:10.3390/plants10091788

Abstract

During the last few years, quinoa, a traditional Andean crop, has been cultivated at low elevations where pest pressure is high and farmers resort to intensive use of insecticides. This field study investigated the impact of four insecticides (cypermethrin, imidacloprid, teflubenzuron and emamectin benzoate) on insect pests of quinoa and their side effects on the arthropod community at the coastal level of Peru, by analysing the species composition, species diversity and population density. The arthropod community was examined with pitfall traps (for ground dwelling species), plant samplings (for pests and their natural enemies that inhabit the crop), and yellow pan traps (to catch flying insects). The results demonstrated that Macrosiphum euphorbiae, Frankliniella occidentalis and Spoladea recurvalis were efficiently controlled by cypermethrin and imidacloprid; the latter compound also showed long-term effects on Nysius simulans. Teflubenzuron and emamectin benzoate proved to be efficient to control S. recurvalis. Imidacloprid had the strongest adverse effects on the arthropod community in terms of species diversity, species composition and natural enemy density as compared to the other insecticides. Findings of this study may assist farmers intending to grow quinoa at the coastal level in selecting the most appropriate insecticides under an integrated pest management approach.

Highlights

Quinoa is an Andean grain that has increasingly gained international interest due to its high nutritional value [1]
The present field study provides information about the effects of four insecticides from different chemical groups on target and non-target arthropods in quinoa, assessed with three sampling methodologies: pitfall trapping for the ground dwelling arthropods, plant sampling for those that dwell on the quinoa plants and pan trapping for the insects that fly just above the crop canopy
When an insecticide is incorporated into the cropping system, changes in the structure, richness and composition of the plant dwelling arthropod community may occur, which may eventually lead to a disruption of the ecosystem services provided by the beneficial fauna [37,38,39,40]

Summary

Introduction

Quinoa is an Andean grain that has increasingly gained international interest due to its high nutritional value [1]. The cultivated area of quinoa has substantially increased in South American countries such as Ecuador, Chile and . There have been attempts of cultivating quinoa outside of its Andean place of origin, in countries such as the United. In the Andes, at an altitude between 2300 and 3800 m a.s.l., quinoa is traditionally cultivated since ancient times [7]. In this region Eurysacca melanocampta Meyrick and Eurysacca quinoae Povolvý are the key pests of quinoa, causing damage by feeding on the developing grains; a range of other phytophagous insects are considered of minor importance [2,6]

Methods

Results

Discussion

Conclusion