Vol. 10, Issue 9 (2021)

Author(s):
Nischala A, S Jeyarajan Nelson, V Balasubramani, VP Sathanakrishnan, A Lakshmanan and K Rajamani

Abstract:
Experiments were conducted to study the repellent activity of the phytochemicals viz., citral, β - Citronellol, trans - cinnamaldehyde, eucalyptol, geraniol, β - myrecene and thymol against the cigarette beetle, Lasioderma serricorne (F.) under laboratory conditions. Trans - cinnamaldehyde and eucalyptol showed cent per cent repellent effect whereas β – myrecene, thymol and geraniol exhibited 97.5, 70.0 and 57.5 per cent repellent effect against adults of cigarette beetle at 31.0 nL/cm² after exposing for 2 h, respectively. In contrary to the behavioural response of L. serricorne adults to trans - cinnamaldehyde, eucalyptol, geraniol, β - myrecene and thymol, citral (-22.5%) and β - citronellol (-30%) attracted the adults of cigarette beetle at very low concentrations viz., 1.5 nL/cm² and 7.8 nL/cm² even after 2 h exposure but repelled insects at 31.0 nL/cm² after exposing for 2 h. But the repellent effect of all phytochemicals at different concentrations decreased after exposing for a period of 24 h.