~ 1799 ~ Journal of Entomology and Zoology Studies 2017; 5(5): 1799-1802 E-ISSN: 2320-7078 P-ISSN: 2349-6800 JEZS 2017; 5(5): 1799-1802 © 2017 JEZS Received: 20-07-2017 Accepted: 21-08-2017 S Sabiha Department of Zoology, University of Rajshahi, Bangladesh Hasan Ali Department of Zoology, University of Rajshahi, Bangladesh Kamrul Hasan Department of Zoology, University of Rajshahi, Bangladesh ASMS Rahman Department of Zoology, University of Rajshahi, Bangladesh Nurul Islam Professor, Department of Zoology, University of Rajshahi, Bangladesh Correspondence Nurul Islam Professor, Department of Zoology, University of Rajshahi, Bangladesh Bioactive potentials of Melia azedarach L. with special reference to insecticidal, larvicidal and insect repellent activities S Sabiha, Hasan Ali, Kamrul Hasan, ASMS Rahman and Nurul Islam Abstract A lab experiment was conducted during June 2015 - Feb 2016 at the Crop protection & Toxicology Lab., University of Rajshahi, Bangladesh to evaluate the insecticidal, repellent and larvicidal efficacy of Petroleum ether (Pet. ether), CHCl3 and CH3OH extracts of the fruits and leaves of Melia azedarach against adults of Tribolium castaneum and larvae of. Tribolium adults exhibited mortality when exposed to all the doses of Pet. ether extracts of fruits and leaves whereas the CHCl 3 and CH3OH extracts of the same didn’t show mortality at all. All extracts showed larvicidal activity by yielding different LC50 values in different time exposure. The Pet. ether extracts of fruit did not show repellent activity, while the Pet. ether extract of leaf showed repellent activity at 5% level of significance ( P<0.05) and the CHCl3 and CH3OH extracts of both fruit and leaf offered repellent activity at 5% level of significance (P<0.05). Keywords: Melia azedarach, Tribolium castaneum, Culex quinquefasciatus, Insecticidal, Larvicidal and Insect repellent activity 1. Introduction Increasing concern about the risks from synthetic insecticides to the environment and human health has led to a major trend in current pest management strategy, which involves searching for less hazardous chemicals or biologically based products [1] . Botanical products fit within this strategy, being biodegradable and effective against pests without harming beneficial insects [2] . M. azedarach L. (locally known Ghoda Neem) belongs to the family Meliaceae, is a highly significant medicinal plant found almost everywhere in Bangladesh [3] . Each and every part of the M. azedarch have traditional medicinal uses like stem is prescribed internally against asthma, bark is used in case of fever to relieve thirst, nausea, vomiting and general debility, loss of appetite and skin diseases. Leaves also relieve from headache and cure the eruption on the scalp. Leaf juice is anthelmintic, diuretic, vermifuge and their decoction is astringent and stomachic. Fruits are used for the preparation of tonic which is purgative, emmolient and anthelmintic. Seeds are bitter, expectorant, anthelmintic and aphrodisiac and are useful in helminthiasis, typhoid fever, pain in the pelvic region and scrofula. Roots are also bitter, astringent, anodyne, depurative, vulnerary, antiseptic, anthelmintic, constipating, expectorant, febrifuge, antiperiodic, and bitter tonic in low doses [4] . The present work aimed at evaluation of the insecticidal and repellent activities of M. azedarach leaf and fruit extracts against the severe stored product pest, T. castaneum (Hbst.) (Coleoptera: Tenebrionidae) adults and larvicidal activity of same against the filarial vector , C. quinquefasciatus Say (Diptera: Culicidae). T. castaneum is a primary pest of flour and other milled products of cereals and a secondary pest of stored wheat [5-8] causing severe damages to quantity and quality of these food grains [9] . Adults are reddish-brown in color, flattish curved sided body, head is visible from above, antennae capitate type and thorax has slightly curved sides [10] . On the other hand C. quinquefasciatus is a widely distributed species of mosquito throughout the world. This mosquito has been found breeding in shallow ponds within streams [11] and artificial habitats such as drains and drain sumps [12] , septic tanks, rain water containers, tyres, etc. [13-14] . Adult C. quinquefasciatus vary from 3.96 to 4.25mm in length [15] . The eggs are not desiccation resistant and are laid as rafts on the water surface [16] . Most eggs hatch into larvae (Wrigglers) within 2-3 days and they swim actively in water by wriggling movements [17] . The present work aimed to evaluate the repellent and insecticidal effects of Pet. ether, CHCl 3 and CH3OH extracts of M. azedarach fruits and leaves. For the evaluation of insecticidal activities and for the repellency test the red flour beetle, T. castaneum (Hbst.) adults were used