New Horizons in Insect Science Towards Sustainable Pest Management

83

Insect Resistance to Bacillus

thuringiensis (Bt) Transgenic Crops

and Its Management

Leena Pathak, Noushad Parvez, Ankit Patel and Janardan

Jani

A. K. Chakravarthy (ed.), New Horizons in Insect Science: Towards Sustainable Pest Management,
DOI 10.1007/978-81-322-2089-3_9, © Springer India 2015

L. Pathak () · N. Parvez · A. Patel · J. Jani
Biological Control Research Laboratory, Anand Agricul-
tural University, 388110 Anand, Gujarat, India
e-mail: [email protected]

Abstract

Transgenic crops producing Bacillus thuringiensis (Bt) toxins for insect–

pest control have been successful and started paying lucrative returns to the

farmers in terms of increased production due to low pest damage, savings in

cost of pesticides and manpower involved for pest control. However, their

efficacy shows a reducing trend due to evolution of resistance among the

target pests is a significant environmental risk. Resistance is a genetically

based decrease in susceptibility of a population to an insecticide. To date,

field-evolved resistance to Bt crops has been documented in only three

insect species: Helicoverpa zea Boddie, Spodoptera frugiperda Smith, and

Busseola fusca Fuller to Bt cotton and Bt corn producing Cry1Ac, Cry1F,

and Cry1Ab, respectively. Scientists in the industry, government, and aca-

demia now recognize evolution of resistance to Bt in pests as a great threat

to the continued success of Bt. Insect Resistance Management (IRM) strat-

egies begin with resistance risk assessment. Phenotypic monitoring meth-

ods are best studied for low-dose events and genic methods are best suited

for high-dose events. Resistance risks are real. But they can be managed.

Resistance issues are associated with first-generation technologies and

incomplete or compromised IRM programs. Next generation technologies

(NGS) with multiple pyramided modes of action are needed.

hind by the insect species have proved to be an

uphill task for agriculturists to answer. Perhaps

the most serious threat to the durability of this

novel insect control technology is the potential

of insect populations to develop resistance to

Bt Cry proteins. Despite many efforts over the

successful exploitation of Bt, some insects have

developed resistance to Bt-toxin. This situation

contributed to the development of biological con-

Keywords

Insect · Resistance · Bt transgenic

Introduction

Even though, Bacillus thuringiensis (Bt) has been
widely exploited, some critical questions left be-