Light trap, an effective component of integrated management of Tuta absoluta(Lepidoptera : Gelechiidae) on Tomato V. Sridhar*1 and G. Senthil Kumaran2 1Division of Entomology and Nematology, 2Division of Post-Harvest Technology and Agricultural Engineering, ICAR-Indian Institute of Horticultural Research, Bengaluru – 560 089 *E-mail: Sridhar.V@ icar.org.in ABSTRACT The effectiveness of mass trapping the moths of Tuta absoluta was evaluated using light traps in tomato polyhouse at ICAR-Indian Institute of Horticultural Research, Bengaluru during March - June, 2018. Various colours of light sources were evaluated for their efficacy in attracting the moths. Of different coloured light sources evaluated, yellow and white (bluish) were found relatively effective for attraction of the moths. The efficacy of mass trapping was further evaluated and incandescent yellow bulb of 60 W was found most efficient in attracting both sexes of Tuta moths. Thus light traps can be an effective tool for IPM of this pest on tomato, under polyhouse conditions. Key words: Tuta absoluta, light trap, mass trapping Short Communication INTRODUCTION Insect attraction to different light sources is a known fact and light trapping is an ideal method for surveying nocturnal moth population. Light trap collections provide a significant clue to understand the diversity of nocturnal insects which differ in their affinity to varied wavelengths of light (Southwood and Henderson, 2000). As an alternative to chemical based pest management, light traps have been used in dif f er en t c ou nt r ies in p es t ma na gement (Srivastava et al., 1992; Oliveira et al., 2008; Ma et al., 2009). In India, Tuta absoluta (Lepidoptera: Gelechiidae) has been reported from Karnataka and Maharashtra during 2014 and has further spread to all the ma jor tomato-growing r egions/states (Sridhar et al., 2014;Swathi et al., 2017). The pest can cause up to 100% crop loss in both greenhouse and open field cultivated tomato. The leaf-mining habit of this pest makes chemical or biological control more difficult. As an alternative, mass trapping could be useful in the management of T.absoluta. Light traps are advantageous over pheromone traps as they attract both male and female moths (Cocco et al., 2012). Information on type of light source effective against T. absoluta is scanty. Hence, the present study was conducted to identify the visible range for the maximum attraction of T. absoluta adults. The trials were conducted in a tomato polyhouse located at ICAR-Indian Institute of Horticultural Research, Bengaluru during March – June 2018. Initially, different light sources in the visible spectrum (wavelength of 390 – 700 nano meters) were screened for attracting tomato moth, T. absoluta during March 2018.Based on initial evaluation results, different bulbs viz., LED 8W; Incandescent bulb (15W, 40W, 60W) and CFL 10W which attracted relatively more moths of T. absoluta were installed in the tomato polyhouse. The tomato crop was 50 days old after transplanting and was in flowering stage when the light traps were installed. The observations/counts on number of moths trapped were taken daily for 5 days to assess the best source of light attracting maximum number of Tuta moths. The number of males and females attracted to the light source were differentiated based on the size and wing colour pattern and also based on genetalia. Incandescent (yellow) bulb was found most effective followed by white (bluish) in attracting Tuta moths. Of all the bulbs under study, Incandescent (yellow) 60 W bulb attracted maximum number of Tuta J. Hortl. Sci. Vol. 13(1) : 126-128, 2018 126 127 Sridhar and Senthil Kumaran J. Hortl. Sci. Vol. 13(1) : 126-128, 2018 adults i.e., 2953 catches within 5 days when compared to other sources of light tested (Table 1, Fig. 1 & 2). Of the total catch, up to 46 per cent catch of the moths constitutes females and thus use of light traps can be an effective tool in the integrated management of T. absoluta. Light traps have been effectively used for the management of pests in cotton and rice (Srivastava et al., 1992; Ma et al., 2009). As the light traps can also attract some of the natural enemies, there is a need to study the peak activity of the pest, so that timer based automated (switch on and off) light traps can be designed, which can minimise trapping of natural enemies. Table 1. Relative catches of T. absoluta moths in different light traps Source of Day 1 Day 2 Day 3 Day 4 Day 5 Males Females light/Bulb* (12/5/18) (13/5/18) (14/5/18) (15/5/18) (16/5/18) Total (%) (%) LED 8 W (Bluish 170 770 492 454 318 2204 54 46 white) Incandescent 15 W 130 250 225 410 201 1216 55 45 (Yellow) Incandescent 40 W 150 350 330 390 140 1360 55 45 (Yellow) Incandescent 60 W 260 892 671 820 310 2953 54 46 (Yellow) CFL 10 W 130 495 352 410 158 1545 58 42 (Milky white) *Per cent female catches in these light traps ranged from 42 - 46 %. Fig 1. Light trap installed in tomato polyhouse Fig 2. Tuta moths attracted to 60 W yellow incandescent light From the present study, we conclude that, incandescent (yellow) 60 W bulb can be used as an efficient tool/component in IPM for management of T. absoluta on tomato, under polyhouse condition. ACKNOWLEDGEMENT The authors are thankful to the Director, ICAR-Indian Institute of Horticultural Research, Bengaluru for providing facilities. 128 Light traps for Tuta management J. Hortl. Sci. Vol. 13(1) : 126-128, 2018 REFERENCES (MS Received 06 June 2018, Revised 17 June 2018, Accepted 29 June 2018) Southwood, T. R. E. and Henderson, P. A. 2000.Ecological methods. Blackwell Science, UK, p 269 - 292. Sridhar, V., Chakravarthy, A. K., Asokan, R., Vinesh, L. S., Rebijith, K. B. and Vennila. S. 2014. New record of the invasive South American tomato leaf miner, Tuta absoluta(Meyrick) (Lepidoptera: Gelechiida e) in India . Pest Manag. Hort. Ecosys.,20:148-154. Srivastava,V.K., Diwakar, M. C. and Pawar, A. D. 1992. Light trap and rice pest management. Plant Prot. Bull.(Faridabad),44: 39–41. Swathi, P., Swathi, B., Das, S.B., Sridhar, V., Giribabu, O., G. Snehalatha, G., Neelesh Raypuriya. 2017. First report of South American tomato leaf miner, Tuta absoluta (Meyrick) from Madhya Pradesh, India. Pest Manag. Hort. Ecosys., 23:92-93. Cocco, a., deliperi, s. and delrio, g. 2012. Potentia l of ma ss tr a pping f or tuta absol uta management in greenhouse tomato crops using light and heromone traps. Integrated control in protected crops, mediterranean climate. Iobc-wprs bul., 80: 319-324. Ma, C.S., Ma, G., Chang, X.Q. and Yang, H.P. 2009. Environment-friendly methods for controlling cotton bollworm moths, Helicoverpa armigera. Chin. J. Environ. Entomol.,31: 220–226. Oliveira, A.C., Veloso, V.R., Barros, R.G., Fernandes, P.M. and Souza, E.R. 2008. Capture of Tuta absoluta (Meyrick) (Lepidoptera: Gelechiidae) with light trap in tomato crop. Pesq. Agropec. Trop.,38: 153–157.