Phosphine resistance in rusty grain beetle Cryptolestes Ferrugineus (Stephens) from South India Muralitharan V.*, Rajan T. Sonai, Chandrasekaran S., Mohankumar S.1 Department of Agricultural Entomology, CPPS, Tamil Nadu Agricultural University, Coimbatore, 641003 1Department of Plant Biotechnology CPMB&B, Tamil Nadu Agricultural University, Coimbatore, 641003 *Corresponding author Email: muraliento@gmail.com
Online published on 23 October, 2018. Abstract Fumigation with phosphine gas is the most common method of disinfestation of stored grains from insect pests. However, the indiscriminate and prolonged use of phosphine gas resulted in the development of heritable resistance in most of the stored grain insect pests including rusty grain beetle, Cryptolestes ferrugineus. The recent high level of phosphine resistance is threatening the grain storage. There is no detailed information available on the level of phosphine resistance in Indian populations of C. ferrugineus particularly in south India. Forty samples of C. ferrugineus were collected from different food grain reserves across four major southern states of India viz., Tamil Nadu, Telangana, Andhra Pradesh and Kerala. The frequency of resistance was evaluated with resistance bioassay with two discriminating concentrations, 0.05 and 1.0 mg L−1 over 20 and 168 hr, respectively. The results revealed that the resistance was common in all the field collected populations of C. ferrugineus with two level of resistance viz., weak and strong resistance and the frequency is ranging from 20.22 to 94.12% in Tamil Nadu, whereas it was 78.65 to 88.64% in confined samples from Telangana. In Andhra Pradesh it was up to 73.33 to 95.00% and 32.88 to 97.70% in Kerala at low concentration of phosphine gas (0.05 mg L−1). In high concentration (1.0 mg L−1), the frequency of resistance was observed ranging from 5.00 to 34.44, nil, 13.56 to 60.34 and 8.89 to 50.56% in Tamil Nadu, Telangana, Andhra Pradesh and Kerala, respectively. Among the populations evaluated, the populations from Guntur, Thrissur, Egmore, Sattenapalle, Nandyal, Kadapa, Cochin, Duggirala, Madurai and Kannur exhibited high level of strong resistance to phosphine suggesting that these populations might have been exposed repetitive selections with high concentration of phosphine gas over long period of time. Top Keywords Cryptolestes ferrugineus, phosphine resistance, frequency, Andhra Pradesh, Tamil Nadu, Telengana, Kerala. Top |