Semiochemicals of rose aphid, black citrus aphid (Hemiptera: Aphididae) and greenhouse thrips (Thysanoptera: Thripidae)

Macrosiphum rosae L. or rose aphid, Toxoptera citricida Kirkaldy or black citrus aphid (Hemiptera: Aphididae) and Heliothrips haemorrhoidalis Bouché or greenhouse thrips (Thysanoptera: Thripidae) are serious cosmopolitan phytophagous pests that can cause severe damage to many cultivated crops. The aim of this study was to investigate the chemical signals utilized by these pests in order to carry out their everyday functions. This was achieved by determining the nature of volatile compounds in the secretions of the rose aphid, the black citrus aphid and the greenhouse thrips. The results obtained showed similarities not only between the two aphid species but also between aphids and thrips with acids and their methyl esters, aldehydes and alkanes being common components of the secretions. E-β-farnesene, a known alarm substance in many aphid species, was confirmed to be a constituent of the secretions of the rose aphid and was isolated for the first time from the black citrus aphid. Results indicated that the sesquiterpene is metabolically produced by the insects and used when required.