A Study of the Effect of Neem (Azadirachta indica) and Thyme (Thymus vulgaris) Seed Oils on the Life of Tribolium castaneum
1 Department of Biology, Colleg of Education for Pur Sciences, University of Samarra, Iraq.
2 Department of Biotechnology, College of Applied Sciences, University of Samarra, Samarra, Iraq.
Research Article
International Journal of Biological and Pharmaceutical Sciences Archive, 2026, 11(02), 199-204.
Article DOI: 10.53771/ijbpsa.2026.11.2.0062
Publication history:
Received on 15 May 2026; revised on 22 June 2026; accepted on 24 June 2026
Abstract:
The current experiment sought to investigate the putative insecticidal efficacy of Azadirachta indica (neem) and Thymus vulgaris (thyme) essential oils on the fourth instar larvae and adults of Tribolium castaneum at 2%, 4% and 8% concentrations. Hypothetical findings indicated that mortality was positively related to both the increase in oil concentrations and increase in time duration of exposure. In the case of fourth instar larvae, neem oil resulted in mortalities of 23.3%, 36.7%, and 50.0% within 24 h which increased to 53.3%, 76.7%, and 96.7% when 2%, 4%, and 8% concentrations were exposed for 48 h, respectively. On the other hand, thyme oil resulted in mortalities of 16.7%, 30.0%, and 43.3. The mortality levels were recorded for adult beetles and were as follows: Neem oil caused mortality of 20.0%, 30.0% and 40.0% in 24 hours, 33.3%, 50.0% and 66.7% in 48 hours, while in 72 hours mortality was observed to be 76.7%, 90.0% and 100% at concentrations of 2%, 4% and 8%, respectively. The mortality percentages of thyme oil after 24 hours were 13.3%, 23.3%, and 33.3%, after 48 hours were 26.7%, 40.0%, and 56.7%, while 72 hours were 66.7%, 80.0%, and 93.3%. Generally, according to the theoretical findings, it is possible to state that neem oil had higher insecticidal efficiency than thyme oil towards both larvae and adults of T. castaneum. In both cases, mortality has been significantly enhanced by the increasing concentrations and duration of time. It can be concluded that botanical oils have the potential of being used as environmentally-friendly alternatives to insecticides.
Keywords:
Azadirachta indica; Thymus vulgaris; Tribolium castaneum; Insecticidal activity; Botanical insecticides; Stored product pests.
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