Termiticidal Activities of Some Medicinal Plants Extracts against Termites, Macrotermes subhyalinus Rambburi (Isoptera: Terminidae) Under Laboratory Conditions

The use of environmentally friendly chemicals for termite management has been of global concern. This study examined the effects of five naturally occurring plant extracts from Azadirachta indica, Datura metel, Allium sativum, Zingiber officinale and Nicotiana tabacum against the termite Macrotermes subhyalinus. Methanol extraction of the plant samples was carried out using cold extraction method. From the stock solutions, for each of the plant samples, different extract concentrations of 2%, 4%, 6%, 8% and 10% were prepared separately. The phytochemical screening of the test plant samples for various phytochemical constituents, such as phenols, terpenoids, flavonoids, alkaloids, glycosides, phenol, saponins and tannins was also conducted using Standard Methods. The results obtained showed that termite mortality increased with increased extract concentration and the number of days of exposure. All the tested plant extracts were able to evoke 100% mortality within four days of exposure at higher concentration of 10%, except in A. indica extract which evoked 100% mortality within four days of exposure at the concentration of 8%. Phytochemical screening of the test plant samples revealed the presence of the phytochemicals such as phenols, terpenoids, flavonoids, alkaloids, glycosides, saponins and tannins in all the plants except for A. sativum where phenol was not detected. All the test plants recorded significant termites mortalities within 4 days hence hence, Azadirachta indica, Datura metel, Allium sativum, Zingiber officinale and Nicotiana tabacum are hereby recommended to be used in the control of termite, Macrotermes subhyalinus. The plant extracts are viable alternatives to the synthetic chemical insecticides used in controlling the insect.