Olfaction of leaf volatiles determines the most attractive host plant for Aleurodicus rugioperculatus Martin (Hemiptera: Aleyrodidae): potential pest management opportunities

The rugose spiralling whitefly (RSW), an invasive poly­phagous insect introduced into India in 2016, has threatened coconut and other crops. Natural infestation intensity data indicated, in order, the following most likely RSW hosts: Cocos nucifera L. (75.83%) > Dypsis lutescens H. Wendel (55.83%) > Annona squamosa L. (54.17%) > Musa paradisiaca L. (43.33%). A preference analysis of these four host plants showed that coconut was the most favoured (8.17 spirals per 30 cm2 and 33.04 eggs per spiral). Olfactometry of the headspace leaf volatiles revealed that C. nucifera (3.05 ± 0.27 min) and D. lutescens (1.67 ± 1.67 min) had longer residence durations and attracted more RSW females than the other hosts. According to principal component analysis, those potential hosts shared six volatile compounds, the most peculiar of which was 2-ethyl-1-hexanol. Gas chromatography coupled electro­antennographic detection analysis revealed that 2-ethyl-1,3-dioxolane, 1,3-dioxolane, 2-propyl, butanoic acid, 2-hydroxy-2-methyl-methyl ester, m-ethyltoluene, p-dichlorobenzene and 2-ethyl-1-hexanol evoked consi­stent olfactory responses in RSW. More studies on these chemicals might help develop parakairomones for managing RSW