The Spread of Helicoverpa armigera (Lepidoptera: Noctuidae) and Coexistence with Helicoverpa zea in Southeastern Brazil.

Fábio Pinto,Simon Elliot,Farley Silva,Marcos Mattos,Silma Rocha

doi:10.3390/insects8030087

Abstract

Helicoverpa armigera, one of the world’s most destructive crop pests, was first documented in Brazil in 2013. Within a few months, this polyphagous insect had spread over the Northeast and Central-West of Brazil, causing great agricultural losses. With several reports of populations resistant to pesticides and Bt crops around the world, there is great concern about the spread of this pest in Brazil. There is confusion about the actual distribution of this species due to the high morphological similarity with the native corn earworm Helicoverpa zea, which may also coexist with H. armigera in the field. Our aims here were (i) to confirm its presence in the State of Minas Gerais, one of the most important agricultural regions in the country; and (ii) to assess the co-occurrence of this pest with the congeneric corn earworm H. zea. Using molecular screening, we confirmed the presence of H. armigera in Bt-crops of soybean and cotton, and non-Bt-crops of soybean, cotton and maize. Mixed infestations of H. armigera with H. zea were found in non-Bt maize (Viçosa, Southeastern Minas Gerais). These results highlight the need for adequate control strategies for H. armigera in Brazil, to deal with its polyphagous feeding habits, high dispersal capacity and possible risks of hybridization with congeneric species.

Highlights

The old world bollworm Helicoverpa armigera (Hübner) (Lepidoptera: Noctuidae) is considered one of the most important agricultural pests in the world
Our results extend the knowledge on the presence and plant hosts of H. armigera in Brazil, with
Our results extend the knowledge on the presence and plant hosts of H. armigera in Brazil, with particular reference to Minas Gerais

Summary

Introduction

The old world bollworm Helicoverpa armigera (Hübner) (Lepidoptera: Noctuidae) is considered one of the most important agricultural pests in the world. Until recently, this pest was considered absent in the Americas. Specific identification is complex and there is the potential for misidentification due to morphological similarities between H. armigera and the corn earworm Helicoverpa zea [5]. For these reasons, molecular analysis (for example PCR-RFLP) is necessary in most cases to distinguish these two species [5]. Our aim here was (i) to confirm the presence of H. armigera in economically important crops in the Southeast of Brazil and (ii) to assess whether H. armigera and H. zea co-occur in this region

Methods

Discussion

Sampling

Conclusions