Defoliation of Soybean Expressing Cry1Ac by Lepidopteran Pests.

María Murúa,Andrew Michel,Sofia Fogliata,Martín Vera,María Herrero

doi:10.3390/insects9030093

Abstract

Lepidoptera, stink bugs, and weevils are important pests in soybean. For lepidopteran control, insecticides and seed treatments are used. As an alternative, Bt soybean was developed to control primary pests of Lepidoptera such as Rachiplusia nu (Guenée) (Noctuidae), Chrysodeixis includens (Walker) (Noctuidae), Anticarsia gemmatalis Hübner (Erebidae), Helicoverpa gelotopoeon (Dyar) (Noctuidae), and Crocidosema aporema (Walsingham) (Tortricidae). However, the use of transgenic plants, and the resulting reduction of insecticide against target pests, may allow other pest species to become more prevalent in agricultural environments. Soybean expressing Cry1Ac against different lepidopteran nontarget and target insect pests was evaluated, and its performance was compared with non-Bt soybean with seed treatment. The treatments were Bt soybean, non-Bt soybean with seed treatment (Fortenza® diamide insecticide, Syngenta, Buenos Aires, Argentina), and non-Bt soybean without seed treatment. Larvae of H. gelotopoeon, Spodoptera albula (Walker) (Noctuidae), Spodoptera cosmiodes (Walker) (Noctuidae), Spodoptera eridania (Stoll) (Noctuidae), and Spodoptera frugiperda (J. E. Smith) (Lep.: Noctuidae) were used. The plants of each treatment were infested with larvae of each species, and the percentage of leaf damage produced by each species was recorded. The results showed that Bt soybean provided control of H. gelotopoeon and had a suppressive effect on S. frugiperda and S. albula. However, S. eridania and S. cosmiodes were not susceptible to the Cry1Ac protein in MON 87701 × MON 89788 soybean when evaluated by greenhouse infestation. Considering the performance of each species using non-Bt soybean without seed treatment, S. eridania would represent a potential risk in soybean crops.

Highlights

Soybean (Glycine max (L.) Merrill) is an oilseed plant of the family Fabaceae that is widely planted in various countries worldwide [1]
The best control of S. eridania was with the non-Bt soybean plus Fortenza® treatment, registering a lower percentage of defoliation compared to
On the performance analysis made among the species using non-Bt soybean without seed treatment other hand, the performance analysis made among the species using non-Bt soybean without seed showed which of these species would represent a potential risk for soybean crops

Summary

Introduction

Soybean (Glycine max (L.) Merrill) is an oilseed plant of the family Fabaceae that is widely planted in various countries worldwide [1]. Bt soybean provides control for the primary Lepidopteran pests of soybean such as Rachiplusia nu (Guenée) (Lep.: Noctuidae), Chrysodeixis includens (Walker) (Lep.: Noctuidae), Anticarsia gemmatalis Hübner (Lep.: Erebidae), Helicoverpa gelotopoeon (Dyar) (Lep.: Noctuidae), Crocidosema aporema (Walsingham) (Lep.: Tortricidae), Colias lesbia (F.) (Lep.: Pieridae), Spilosoma virginica (F.) (Lep.: Arctiidae), Chloridea virescens (F.) (Lep.: Noctuidae), and Achyra bifidalis (F.) (Lep.: Crambidae). This technology can suppress populations of Spodoptera frugiperda The use of Bt plants and the resulting reduction of insecticide use against target pests may allow other pest species to become more relevant in agricultural environments [9]

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