World Journal of Agricultural Research, 2015, Vol. 3, No. 1, 1-4 Available online at http://pubs.sciepub.com/wjar/3/1/1 © Science and Education Publishing DOI:10.12691/wjar-3-1-1 Screening of Two Ocimum tenuiflorum L. (Lamiaceae) Morphotypes for their Morphological Characters, Essential Oil Composition and Fruit Fly Attractant Ability R.M. Dharmadasa 1,* , D.A.S. Siriwardhane 1 , K. Samarasinghe, S.H.C.S. Rangana 1 , L. Nugaliyadda 2 , Indika Gunawardane 3 , A.M.L. Aththanayake 1 1 Industrial Technology Institute, 363, Bauddhaloka Mawatha, Colombo 7, Sri Lanka 2 Faculty of Agriculture, University of Ruhuna, Kamburupitiya, Sri Lanka 3 CIC Holdings, Colombo -2, Sri Lanka *Corresponding author: dharmadasarm@gmail.com Received December 14, 2014; Revised December 24, 2014; Accepted January 05, 2015 Abstract Bactrocera dorsalis (Hendel) (Diptera: Tephritidae) is the destructive pest of over 300 cultivated and wild fruits all over the world. Present study describes the morphology, essential oil content and composition and bioassay on fruit fly attractant ability of essential oil of two Ocimum tenuiflorum morphotypes (MT 1 purple and MT 2 purple-green) grown in Sri Lanka. Four months old, O. tenuiflorum aerial parts were hydro-distilled for 4 h. GC-MS analysis of essential oils and bio-assay for B. dorsalis attractant ability was performed using previously established methodologies. The yield of the essential oils of O. tenuiflorum MT 1 and MT 2 were 1.51±0.02% and 1.45±0.01% (v/w), respectively. Eighteen compounds were identified, which encountered over 97% of the oil constituents. The main constituents found in the oil of MT 1 were methyl eugenol (72.50±1.03%) followed by β-caryophyllene (17.53±2.0%), germacrene D (1.55±0.10%), β-elemene (2.46±0.17%), while methyl eugenol (64.23±2.43%), β- caryophyllene (13.29±2.18%), β-elemene (6.94±1.41%), germacrene D (2.47±0.96%), were from extracted from MT 2 . Bioassays conducted on essential oils of MT 1 , MT 2 and purified Methyl Eugenol demonstrated that the B. dorsalis attractant ability of essential oil MT1 (106±8.1), MT2 104±2 and commercial Methyl Eugenol (111±8.5) was not significantly different during the first week of the experiment. Results of our study open an avenue for use of essential oil of Ocimum tenuiflorum as potential natural para pheromone source for fruit fly control and monitoring in fruit industry in Sri Lanka. Keywords: Ocimum tenuiflorum, Lamiaceae, fruit fly, methyl eugenol, parapheromone, essential oil Cite This Article: R.M. Dharmadasa, D.A.S. Siriwardhane 1 , K. Samarasinghe, S.H.C.S. Rangana 1 , L. Nugaliyadda, Indika Gunawardane, and A.M.L. Aththanayake, “Screening of Two Ocimum tenuiflorum L. (Lamiaceae) Morphotypes for their Morphological Characters, Essential Oil Composition and Fruit Fly Attractant Ability.” World Journal of Agricultural Research, vol. 3, no. 1 (2015): 1-4. doi: 10.12691/wjar-3-1-1. 1. Introduction Bactrocera dorsalis (Hendel) (Diptera: Tephritidae) is the serious destructive pest of over 300 cultivated and wild fruits and vegetables including Annona (sugar apple), avocado, banana, citrus, coffee, guava, mango, papaya, passion fruit, peppers and tomato. This pest will apparently breed in all fleshy fruits [1]. The damage by oriental fruit fly is an impediment for establishment of commercial orchards of fruits than can be grown in Hawaii [2]. A number of methods to control these important pests of fruits, such as chemical control [3], cultural control [4], combinations of insecticides and plant products [5] and culture filtrates of fungi [6] have also been tried out. However, chemical control methods for fruit fly control were unsuccessful [7,8]. The substance that contain single component (males lure) called parapheromone is only effective to capture male fruit fly. Meanwhile, pheromone traps with synthesized methyl eugenol have been used to eliminate the fruit fly damage by many people [9,10,11,12]. Moreover, this technique has been successfully practiced to monitor the fruit fly populations in India and Pakistan [13,14]. However, commercial synthesizing process of methyl eugenol is risky and expensive (US$ 200/kg) and importation of required chemicals for the methylation process is difficult due to its high toxic nature. Therefore, development of an effective, plant based insect attractant, at an affordable price, is urgently needed. Ocimum tenuiflorum L. (Lamiaccae) is one of the most famous, perennial herbs native to Africa, India and Asia, cultivated in temperate climate throughout the world with about 150 varieties. Interestingly essential oil of Ocimum