EFFECTIVENESS OF TRANSGENIC BT MAIZE TO CONTROL Helicoverpa armigera (LEPIDOPTERA: NOCTUIDAE)

Fernando Belezini Vinha,Abílio José Meiato Barrionuevo Oliveira,Carlos Alberto Zambiasi,Alexandre De Sene Pinto,Murilo Gaspar Litholdo

doi:10.28998/rca.v18i3.9726

Fernando Belezini Vinha, Abílio José Meiato Barrionuevo Oliveira + Show 3 more

Open Access

https://doi.org/10.28998/rca.v18i3.9726

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Abstract

The caterpillar Helicoverpa armigera (Hübner) (Lepidoptera: Noctuidae), identified in Brazil in 2013, greatly worries farmers because of its destructive power. The technology of transgenic plants that induces resistance to insects is a great ally for controlling caterpillars. In this study we compared the performance of transgenic Bt maize in the controlling of different larval instars of H. armigera in semi-field seedlings. There were tested the following genotypes: (1) Non-Bt maize Iso-hybrid (Control); (2) Cry1F; (3) Cry1F+ Cry1A.105 + Cry2Ab2; (4) Cry1A.105 + Cry2Ab2; (5) Cry1Ab + Cry1F; (6) Cry1Ab + Vip3Aa20. The experimental design was organized in randomized blocks with eight replications, each consisting of a pot with 5 plants artificially infested with larvae of 2nd, 3rd or 4th instar. At 1, 3, 7, 10 and 14 days after infestation, plants were evaluated for defoliation. In the 3rd instar larvae bioassay, there was high predation by birds, but until seven days after infestation all transgenic maize were efficient to the pest. All transgenic Bt maize were effective in the control of tested H. armigera larvae instars.

Highlights

In recent years, the cotton bollwormHelicoverpa armigera (Hübner) (Lepidoptera: Noctuidae), was introduced and spread throughout South America, especially in Brazil, where in recent years caterpillars of the subfamily Heliothinae have produced great damages in several crops, regardless if transgenic or not (Jones et al.,2019). this pest has been considered a quarantine pest A1 in Brazil, it was recently detected in the states of Goiás, Bahia and Mato Grosso, mainly associated with cotton and soybean crops (Czepak et al, 2013).It is an extremely polyphagous pest whose larvae have been recorded in more than 60 species of wild and cultivated plants and in more than 60 host families, including Asteraceae, Fabaceae, Malvaceae, Poaceae and Solanaceae
Little is known about the effect of bt toxins to H. armigera, in this study, the objective was to compare the performance of Bacillus thuringiensis (Bt) transgenic maize seedlings in the control of H. armigera caterpillars at different instars
In the bioassay where the 2nd instar larvae of Helicoverpa armigera were artificially infested in the different maize genotypes, significant differences were found between treatments

Summary

Introduction

The cotton bollwormHelicoverpa armigera (Hübner) (Lepidoptera: Noctuidae), was introduced and spread throughout South America, especially in Brazil, where in recent years caterpillars of the subfamily Heliothinae have produced great damages in several crops, regardless if transgenic or not (Jones et al.,2019). this pest has been considered a quarantine pest A1 in Brazil, it was recently detected in the states of Goiás, Bahia and Mato Grosso, mainly associated with cotton and soybean crops (Czepak et al, 2013).It is an extremely polyphagous pest whose larvae have been recorded in more than 60 species of wild and cultivated plants and in more than 60 host families, including Asteraceae, Fabaceae, Malvaceae, Poaceae and Solanaceae. Helicoverpa armigera (Hübner) (Lepidoptera: Noctuidae), was introduced and spread throughout South America, especially in Brazil, where in recent years caterpillars of the subfamily Heliothinae have produced great damages in several crops, regardless if transgenic or not (Jones et al.,2019). Little is known about the effect of bt toxins to H. armigera, in this study, the objective was to compare the performance of Bt transgenic maize seedlings in the control of H. armigera caterpillars at different instars.

Results

Conclusion