Evaluation of tomato cultivars to Helicoverpa armigera using two-sex life table parameters in laboratory Sedighe Safuraie-Parizi, Yaghoub Fathipour ⁎, Ali Asghar Talebi Department of Entomology, Faculty of Agriculture, Tarbiat Modares University, P.O. Box 14115-336, Tehran, Iran abstract article info Article history: Received 14 April 2014 Revised 13 August 2014 Accepted 24 August 2014 Available online 30 August 2014 Keywords: Tomato fruitworm Helicoverpa armigera Two-sex life table Demography Resistance Helicoverpa armigera (Hübner) is one of the most important pests of a wide range of agricultural crops world- wide. Resistance of 10 tomato cultivars (‘Primoearly,’‘Riogrand,’‘CaljN3,’‘Kingstone,’‘Earlyurbana,’‘Petomech,’ ‘EarlyurbanaY,’‘Mobil,’‘Imprial’ and ‘Petoearly’) to H. armigera was evaluated under laboratory conditions at 25 ± 1 °C, 60 ± 5% RH and a photoperiod of 16:8 (L:D) hours using age-stage, two-sex life table parameters. The larval period ranged from 19.96 on ‘Riogrand’ to 24.58 days on ‘Imprial.’ The insects reared on ‘Imprial’ had the longest total preoviposition period (44.80 days) and those reared on ‘Riogrand’ had the shortest one (35.44 days). The longest adult longevity for female and male was observed on ‘EarlyurbanaY’ (14.40 days) and ‘Kingstone’ (15.00 days), respectively. Using age-stage, two-sex life table, the value of the net reproductive rate (R 0 ) varied from 7.8 on ‘Imprial’ to 186.9 offspring per individual on ‘Petomech.’ The lowest value of the in- trinsic rate of increase (r) and finite rate of increase (λ) was on ‘Imprial’ (0.0410 and 1.0423 day -1 , respectively) and the highest was on ‘Petomech’ (0.1274 and 1.1359 day -1 , respectively). The mean generation time (T) on different cultivars varied from 39.9 to 48.2 days. The results revealed that ‘Petomech’ was the most susceptible (suitable) and ‘Imprial’ was the most resistant (unsuitable) cultivar to this pest among the tomato cultivars tested. © 2014 Korean Society of Applied Entomology, Taiwan Entomological Society and Malaysian Plant Protection Society. Published by Elsevier B.V. All rights reserved. Introduction Tomato fruitworm, Helicoverpa armigera (Hübner) (Lepidoptera: Noctuidae), is a polyphagous pest that attacks over 100 plant species including widely grown and economically important crops like cotton, corn, tobacco, pigeon pea and chickpea, besides tomato (Talekar et al., 2005). Tomato (Lycopersicon esculentum Mill) is one of the most popular and nutritious vegetable crops in many parts of the world and H. armigera is a common pest in tomato fields worldwide. The young caterpillars burrow into tomato fruits and cause secondary infection resulting in high rate of commercial losses. Chemical insecticides are widely used to control H. armigera on tomato and other crops (Talekar et al., 2005), but this insect has newly developed resistance to a wide range of insecticides (Jadhav and Armes, 1996; Ahmad et al., 1997; Kranthi et al., 2001). Therefore, practical application of host plant resistance to this pest in combination with other control measures is the keystone of integrated pest manage- ment (IPM) programs (Fathipour and Naseri, 2011; Fathipour and Sedaratian, 2013). Development, survivorship, reproduction, and life table parameters of herbivorous insects can be affected by temperature (e.g., Haghani et al., 2006, 2007; Kheradmand et al., 2007; Golizadeh et al., 2009a; Karimi-Malati et al., 2014a,b; Park et al., 2014), and host plant quality (e.g., Golizadeh et al., 2009b; Soufbaf et al., 2010a,b; Naseri et al., 2011; Karimi et al., 2012). Life table provides simple ways to track how a population grows and changes (Khanamani et al., 2013). Therefore, determining the life table parameters of H. armigera would be very useful to assess the suitability (or resistance) of different tomato cultivars to this pest. Even though H. armigera causes large economic losses to tomato every year and it is a key pest of this crop worldwide, life table studies of this pest on different tomato cultivars are rare. Some studies have been conducted on the effects of different host plants on demographic parameters of H. armigera apart from tomato cultivars (e.g., Patal and Koshyia, 1997; Liu et al., 2004; Reddy et al., 2004; Naseri et al., 2009a; Soleimannejad et al., 2010; Karimi et al., 2012). Furthermore some scientists have evaluated the resistance of local tomato genotypes to different insect pests like H. armigera, Tuta absoluta (Meyrick), and Myzus persicae (Sulzer) (e.g., Selvanarayanan and Narayanasamy, 2006; da Silva et al., 2013; Dias et al., 2013; Nemati-Kalkhoran et al., 2013). Selvanarayanan and Narayanasamy (2006) determined the factors of resistance in tomato against H. armigera and suggested that “on correlating the contents of ortho-dihydroxy phenols in the leaves with larval feeding rate, a significant negative correlation was observed, while total phenol content exerted a non-significant negative correlation. Journal of Asia-Pacific Entomology 17 (2014) 837–844 ⁎ Corresponding author. Tel.: +98 2148292301; fax: +98 2148292200. E-mail address: fathi@modares.ac.ir (Y. Fathipour). http://dx.doi.org/10.1016/j.aspen.2014.08.004 1226-8615/© 2014 Korean Society of Applied Entomology, Taiwan Entomological Society and Malaysian Plant Protection Society. Published by Elsevier B.V. All rights reserved. Contents lists available at ScienceDirect Journal of Asia-Pacific Entomology journal homepage: www.elsevier.com/locate/jape