Repellence of Hyptis suaveolens whole essential oil and major constituents against adults of the granary weevil Sitophilus granarius

The essential oil (EO) from Hyptis suaveolens L. (Lamiaceae) was analyzed by gas chromatography (GC) and by gas chromatography/electron impact mass spectroscopy (GC/EIMS), and sixty-six constituents were identified. The H. suaveolens EO contains sabinene (34%), beta-caryophyllene (11.2%), terpinolene (10.7%) beta-pinene (8.2%), limonene (5.8%), and 4-terpineol (2.5%) as major constituents. Moreover, H. suaveolens EO and its major constituents were evaluated for their repellent activity against adults of the granary weevil Sitophilus granarius (L.) (Coleoptera Dryophthoridae) in Petri dish tests and in pitfall bioassays. Data showed that H. suaveolens EO possess a noticeable repellent activity against S. granarius in both testing methods. Furthermore, in all trials good repellence rates of terpinolene, beta-pinene and sabinene were found, in particular at lower dosages. The possibility to incorporate these compounds into packaging materials of foodstuffs, as well as to increase their repellence activity in appropriate formulations, is discussed.