J. Hon. Sci. Vol. 1(1): 39-43, 2006 Pheromone trapping protocols for brinjal shoot and fruit borer, Leucinodes orbonalis Guenee (Lepidoptera: Pyralidae): evaluation of trap design, quantity and dispenser N. K. Krishna Kumar, B. Krishna Kumari', H. S. Singh ,̂ H. R. Ranganath, B. Shivakumara and C. M. Kalleshwaraswamy Division of Entomology & Nematology Indian Institute of Horticultural Research Hessaraghatta Lake Post. Bangalore-560 089. India E-mail: nkkumar@iihr.ernet.in ABSTRACT Studies were conducted at the Indian Institute of Horticultural Research, Bangalore, and Central Horticultural Experiment Station, Bhubaneshwar, India, to evaluate trap design, quantity of pheromone loading and dispensers for attracting brinjal shoot and fruit borer, Leucinodes orbonalis Guenee (Lepidoptera: Pyralidae) using indigenously synthesized pheromone lure [synthesized by Indian Institute of Chemical Technology (IICT), Hyderabad], during 2003 and 2004. A water trap consisting of plastic container (20 cm dia. and 7.5 cm depth) with a facility to place the pheromone septum was designed. Pheromone load of 4 mg in both water trap and Pest Control India (PCI®) delta trap was observed to catch higher number of male moths compared to dispensers with lesser loading. When trap designs were compared, water trap with pheromone lure was observed to attract higher number of males than Pest Control India (PCI®) delta trap. Among the different pheromone dispensers tested, rubber septum was superior to plastic vial or plastic septum. Rubber septum supplied by Bio Pest Management® captured significantly higher number of moths compared to rubber and plastic septum supplied by difTerent firms. A comparison of IICT synthesized lures along with some commercially available lures indicated that Bio Pest Management® lure dispensed in rubber outperformed PCI® and IICT lures. Key words; Brinjal shoot and fruit borer, Leucinodes orbonalis, pheromone traps and lures I N T R O D U C T I O N to be applied daily during summer, which resulted in out- Brinjal (SoZa««m/7zeto«^m«L.) is an economically ^'^^^ °^ s e c o n d a r y p e s t s s u c h as red s p i d e r m i t e , important vegetable in Bangladesh, China, India, Pakistan, Tetranychus cucurbitae R a h m a n and S a p r a ( A c a r i : the Philippines, Sri Lanka and Thailand. Among insect Tetranychidae), and serious health consequences for both pests, brinjal shoot and fruit borer (BSFB), Leucinodes producers and consumers (Kabir et al 1996). orbonalis Guenee (Lepidoptera: Pyralidae) is the most v / i t h the i n c r e a s i n g i m p o r t a n c e a c c o r d e d to destructive pest. It is considered nearly monophagous sustainable agriculture. Integrated Pest Management (IPM) although potato has been recorded as an alternate host • , „ • A \ A * A \ A- ^ A ^ ^ IS becoming more widely adopted, leading to decrease in (Nandihalli^/a/, 1996). At present, farmers rely exclusively j , , • i /T mnox *r. j -c- • c.u . , . • . , , , • „ , use or chemicals (Jones, 1998). After identification of the on chemical insecticides to control this pest. Several . r-r^o^-r, r , • ,^, , , J , • • -J . ,• , maior component or BSFB female sex pheromone (Zhu e-r workers have reported that insecticides such as dimethoate, , phosphamidon. cypermethrin and monocrotophos (Ahmad, ' ' ' ' ^ ^^^' ^ " ^ ^ " ' ^ ''«'' ^ ̂ ^^^' ^ ^ ' ^ Annihilation Technique 1977; Kuppuswamy and Balasubramanian, 1980; Jagan ^^^^^ " ^ ' " ^ ^^^ pheromones is considered to be one of Mohan et al, 1980) are effective in reducing of BSFB. ^he most important components of IPM in BSFB (Cork et Among these, synthetic pyrethroids have been widely used. «/• 2001). The present study was to evaluate the field It is observed that BSFB defies all the chemical control efficacy of indigenously synthesized BSFB pheromone measures. According to Cork et al (2001), farmers spray along with trap design, pheromone dispensers and to 50 to 70 times during the six-month growing season of compare these with some commercially available lures. This brinjal. In Bangladesh, insecticides were recently observed could help to develop mass trapping and IPM of BSFB. ' Organic Division-I. Indian Institute of Chemical Technology. Hyderabad- 500 007, India ^Central Horticultural Experiment Station (IIHR). Bhubaneswar-751 019. India mailto:nkkumar@iihr.ernet.in Krishna Kumar et al MATERIAL AND METHODS Synthesis of individual pheromone components of brinjal fruit and shoot borer was done at Organic Division- I of the Indian Institute of Chemical Technology (IICT), Hyderabad. The pheromone components I [ ( E ) - l l - hexedecenyl acetate] and II [(E)-ll-hexadecen-l-ol] used in this study had > 99.5% isomeric and > 97% product purity. Rubber septa and plastic septa dispensers used for the study were purchased from commercial suppliers and were subjected to solvent pretreatment prior to preparation of pheromone lures. Leucinodes orbonalis sex pheromone lures were prepared by impregnating pre-activated pheromone dispensers with 100:1 blend of ( E ) - l l - hexadecenyl acetate (100) and (E)-lI-hexadecen-l-ol (1). Loadings of the pheromone blend onto the dispensers was adjusted to 0.5 mg - 4.0 mg as per requirement and design of the field experiment. The lures thus prepared were stored in at -20"C until deployment in the field. Trap design The water trap consisted of a plastic container (basin type) of 20 cm dia. and 7.5 cm depth (Fig. 1). The container was filled with water and the pheromone lure was hung 2.5 cm above the water surface using insulated metallic wire. The lure was protected from direct sunlight using a circular plastic plate. The trap was placed 30 cm above the crop canopy using bricks. The trap height with respect to canopy height was adjusted at weekly intervals. Water level in the container was maintained at a constant and lures were replaced with fresh ones every month. A small quantity of soap solution was added to the water to avoid escape of trapped moths. This trap was compared with Delta sticky trap (30 cm x 10 cm; Fig. 2) supplied by Fig. 1. Water trap designed at IIHR PCI (Pest Control India, Bangalore). Observation on the number of male moths trapped was made on a daily basis. Pheromone quantity The experiment was conducted from January - June 2003 using Arka Neelkant, a bacterial wilt resistant brinjal variety, at the Indian Institute of Horticultural Research (IIHR), Bangalore. The pheromone dispenser used in this study was a plastic vial. Different pheromone loadings viz., 0, 0.5, 1.0, 2.0 and 4.0 mg were evaluated for their efficacy in attracting male BSFB moths using water and delta traps. The experiment was laid out in a randomized block design and replicated three times. A distance of 10 m between each treatment and a distance of 15 m between each replication was maintained. Pheromone lures were replenished once in four weeks. PCI delta traps and water traps were placed as and when required. Table 1: Trap catches of Leucinodes orbonalis in water and delta traps with various pheromone loads at IIHR, Bangalore Treatments Water trap with 0.5 mg Water trap with 1.0 mg Water trap with 2.0 mg Water trap with 4.0 mg PCI delta trap® with 0 PCI delta trap® with 1 PCI delta trap® with 2 PCI delta trap® with 4 Water trap with 0.0 mg PCI delta trap with 0.0 CD (p=0.05) CV (%) Total number of moths trapped Mean±SD catch / trap* pheromone load pheromone load pheromone load pheromone load ,5 mg pheromone load 0 mg pheromone load .0 mg pheromone load ,0 mg pheromone load pheromone load mg pheromone load 59 59 61 110 44 39 53 61 II 9 Figures in parentheses are Vx+O.I transformed values ; * = Mean of three replications Superscripts of the same sign in a column indicate non-significant difference 20+1.01(4.35)" 20+0.61(4.31)" 20±0.90(4.27)'' 37±1.52(5.99r 15±0.86(3.80)'> 13±0.27(3.66)'' 18+0.49(4.17)" 20± 1.05(4.41)" 4±0.42(1.89)' 3±0.01(1.69)'^ 1.56 23.65 J. Hon. Sci. Vol. 1(1): 39-43, 2006 40 Pheromone trapping protocols for brinjal shoot and fruit borer Fig. 2 PCP delta trap Pheromone dispenser The experiment was conducted from January to April 2004 using brinjal variety Arka Neelkcmt, at IIHR, Bangalore and at Central Horticultural Experiment Station (CHES), Bhubaneswar. Two dispensers, rubber septa and plastic vials supplied by local commercial firms were evaluated (Table 2). Aldrich rubber septa imported from the United Kingdom was also used in the study. All dispensers were impregnated with 4,0 mg IICT synthesized pheromone these dispensers were placed in PCI® traps (Fig. 3). Seven treatments were imposed following randomized complete block design and replicated four times at IIHR and three times at CHES. Fresh lures were replaced once in four weeks. Comparative evaluation of commercially available IICT-synthesized pheromone lures A study was conducted from September to December 2004 to assess the trapping potential of indigenously synthesized IICT and commercially available lures. The experiment was conducted in randomized block design with four replications. Each replication consisted Fig. 3 PCI' water trap of 98 plants (var. Arka Neelkant) in 5 x 5 m- area with one trap per replication. PCI® water traps (Fig. 3) were used for all the lures. Lures were changed every 4 weeks. The commercial lures evaluated were Bio pest management® rubber septa, Bio pest management® plastic septa and PCI® rubber septa. These three lures of commercial firms were compared with the IICT synthesized lure impregnated in different dispensers. RESULTS AND DISCUSSION Pheromone quantity and trap design Results indicated that the total trap catch was highest in water trap with 4 mg pheromone loading (37.00±1.52 moths/trap) during the trapping period of 6 months. This was followed by a pheromone load of 4 mg in delta sticky trap, which recorded 20.00±1.05 moths per trap. The trap catches in these treatments were significantly higher compared to both water trap and delta trap with 0, 0.5, 1.0 and 2.0 mg pheromone loading (Table 1). Pheromone loadings of 0.5 and 1.0 mg caught significantly less number of moths (Table 1). When water traps and PCI delta traps' were compared irrespective of loading, water Table 2. Catches of Leucinodes orhonalis in water trap with different types of pheromone dispensers (loaded with 4 mg of IICT synthesized pheromone) at IIHR, Bangalore, and CHES, Bhubaneswar IIHR, Bangalore CHES, Bhubaneshwar Treatment Total moths Mean+SD /trap Total moths Mean±SD /trap Aldrich" rubber septa * Abhishek* rubber septa* Basarass- rubber septa* Bio-pest management® rubber septa Bio-pest management- plastic septa Blank CD (p=0.05) CV (%) Figures in parentheses are Vx+0.1 transformed values 29 56 22 69 24 0 7.25+1.60(2.38)"^ 14.00±1.10(3.70)"' 5.50 ±1.19(2.32^ 17.25±1.35(4.01)' 6.00±I.34(2.3I)'» 0.00±0.33(0.32)" 1.452 5.91 66 94 35 107 54 1 22.00±1.8()(4.67)» 3I.33±1.46(5.56)» 11.67±1,59(3.29)»' 35.67±1.69(5.90)" 18.00± 1.12(4.24)'' 0.33±0.12(0.56)' 2.15 30.62 J. Hon. Sci. Vol. 1(1): 39-43, 2(X)6 41 Krishna Kumar et al Table 3. Comparative efficiency of IICT lure dispensed in different septa with commercial lures in attracting L. orbonalis Treatments Pheromone source Total no. of moths Mean±SD per trap per night Abhishek" rubber septa IICT Abhishek'̂ plastic vial IICT Asthagiri- herbal plastic septa IICT Bio pest management® plastic septa Commercial Bio pest management® rubber septa Commercial PCI® rubber septa Commercial Blank / Empty Empty CD CV {%) 160 211 241 501 653 317 7 0.70+0.60(1.06)" 0.90+0.30(1.25)"" 0.90±0.40(1.19)'' 2.10+1.40(1.56)" 2.60+1.70(1.69)" 1.20+0.70(1.30)"" 0.10+0.02(0.72)'^ 0.33 17.99 Figures in parentheses are VX+0.1 transformed values Superscripts of the same sign in a column indicate non-significant difference traps were observed to be more effective than delta traps. Significant variation in trap catches between water and delta sticky traps indicated that water traps were more efficient than delta traps. Water trap is also cheaper and long lasting. Dispensers Pheromone lures dispensed in rubber septa were superior to polyethylene or plastic septa in trapping BSFB moths. In the trials conducted at IIHR, Bangalore and CHES, Bhubaneswar, the Bio pest management® rubber septa trapped maximum BSFB moths. But at CHES, Bhubaneswar, other dispensers performed on par with Bio- pest management® septa even though the latter caught highest number of moths (107 males) with mean of 35.67 per trap. The significant variability in the trap catches across septa indicates that in addition to pheromone loading, use of appropriate dispenser is most important for success in mass trapping. Dispensing septa dictate rate of release of pheromone and that varies with the technology. Hence, variation in response of male moths to pheromone traps is attributed to the nature of the dispenser used. The mean number of moths trapped in Bangalore (17.25 males/ trap) was less compared to that in Bhubaneswar (35.67 males / trap), which indicated that pest density and weather parameters influence trap catches in different regions (Krishna Kumar et al, 2004). Another possibility could be behavioural polymorphism in the populations of L. orbonalis or geographic variation in female sex pheromone which has been reported in many Lepidopteran pests including rice leaf folder, Cnephalocrocis medinalis Guenee (Kawazu et al, 2000) and Helicoverpa annigera (Kumar and Shivakumara, 2002). However, this needs to be confirmed in L. orbonalis. Efficiency of indigenously synthesized IICT lures The performance of commercial lures may vary with the quality and quantity of sex pheromone. Bio Pest Management BSFB pheromone lures in rubber and plastic septa trapped higher number of moths (2.60±1.70 males/ trap/night) (Table 3). Catches in plastic septa and rubber septa of Bio pest management were not statistically different. Number of moths trapped by HCT lures irrespective of type of dispensers was statistically not significant. The HCT lure loaded in three different dispensers were on par with catches of PCI rubber septa. However, the pheromone loading synthesized by IICT was 4 mg/vial and the load in commercial company is unknown. Hence, depending on the cost : benefit ratio, pheromone loading to increase the efficacy of lures needs investigation. The findings in the present study suggest that trap design, quantity of lure and nature of dispensers affect the response of L. orbonalis to synthetic sex pheromone. Water trap with pheromone load of 4mg dispensed in rubber septum is recommended for mass trapping of BSFB. ACKNOWLEDGEMENTS The authors are grateful to the Department of Biotechnology (DBT), Ministry of Science and Technology, Government of India, for financial support. 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