The Nicotiana species are a rich source of potentially valuable, biorational agrochemicals. The multicellular, glandular trichomes on the leaves of most Nicotiana species produce exudates with diverse biological activities. Common cuticular components include duvane diterpenes, labdane diterpenes, and sugar esters (especially sucrose esters). These components may affect the behavior of pestiferous and beneficial insects, and/or they may have insecticidal properties. We have investigated the effects of the cuticular components from several Nicotiana species on the behavior, development, survival, and reproductive potential of the tobacco aphid, Myzus nicotianae Blackman. Cuticular components influence the acceptance or rejection of plants for colonization by migrant aphids, and they affect the survival and fecundity of alate and apterous colonizing tobacco aphids. Correlations between aphid infestation rates in the field and levels of cuticular components on several tobacco, N. tabacum L., lines indicated that a- and ß-4,8,13-duvatriene-1,3-diols (dvt-diols) may act as stimulatory components for colonization by tobacco aphids. Preliminary studies using electronic feeding monitors, also showed trends that suggest that dvt-diols may be important for host acceptance by tobacco aphids. We have identified several cuticular components that are topically toxic to tobacco aphids. Significant correlations of aphid colonization rates with cuticular components also indicated that tobaccos with high levels of a- and ß-4,8,13-duvatrien-1-ols (dvt-ols) or sucrose esters had less severe aphid infestations. Cuticular diterpenes and sugar esters were isolated and purified from the cuticular extracts of several Nicotiana species. These components were bioassayed for their topical toxicity to apterous adult tobacco aphids. The dvt-ols and sucrose esters from several Nicotiana species were especially toxic. Highly active components are being tested in the field as insecticides during the summer of 1994, and these results will be discussed.