Abstract:
Objectives: Paederus fuscipes and Luprops tristis constitute Kerala's two most notorious home-invading
arthropod pests. To control their infestations, indoor application of pesticides is commonly practiced,
which is detrimental to human health and the environment. This study explores the bioactive properties
of plant essential oils as a control agent against them.
Methods: We analyzed the constituents of oils, their repellence, and fumigant toxicity against P. fuscipes
and L. tristis. The constituents and the bioactive compounds in oils were analyzed using Gas
Chromatography-Mass spectroscopy analysis. For the evaluation of the repellence activity of the plant
essential oils- two choice bioassays were performed, where the control was treated with acetone, and
the test contained a mixture of oil in acetone (0.1µL/cm2
). Fumigant toxicity of oils was done by no
choice bioassay (0.1µL/ml air). To determine the potency of the oils, lethal concentration 50 (LC50) was determined; LC50 refers to the concertation of a substance in the air required to kill 50% of the test
animals over a period of time. LC50 of cinnamon oil no choice assay with 0.04µl/ml, 0.06µl/ml, 0.08µl/ml,
0.1µl/ml and 1.2µl/ml concentration was performed.
Results: Of the three plant essential oils, turmeric oil was the best repellent against both P. fuscipes
(86.66±11.54) and L. tristis (40±20). Cinnamon oil showed the highest activity as a fumigant with 100%
and 73.33±46.18% mortality in P. fuscipes and L. tristis after 8 hours of exposure. The analysis of the
constituents indicated the presence of over 63 different chemical compounds in the three oils. The three
plant essential oils tested showed insect deterrent activity, with turmeric oil as the best repellent and
cinnamon oil as the best fumigant against pests.
Conclusions: The activities shown were significant enough to be used to replace/add to the
conventionally used pesticides, especially in indoor settings. These oils in themselves or by isolating the
specific compounds could pave the way to developing more effective and greener pest control methods.
