Journal of Chemical Ecology (1993) 19, 411-425
Ted C.J. Turlings, Philip J. McCall, Hans T. Alborn and James H. Tumlinson (1993)
An elicitor in caterpillar oral secretions that induces corn seedlings to emit chemical signals attractive to parasitic wasps
Journal of Chemical Ecology 19 (3), 411-425
Abstract: Regurgitate of corn-fed beet armyworm (BAW) caterpillars, Spodoptera exigua, when applied to damaged sites of corn (Zea mays) seedlings, causes the release of relatively large amounts of terpenes by the seedlings several hours later. This plant response could be induced by merely placing the cut stem of seedlings in a solution of BAW regurgitate for 12 hr, a response that could not be induced by placing seedlings in water only. Regurgitate of BAW fed various diets, including a minimal diet of filter paper, were all active. However, seedlings placed in corn leaf juice, BAW hemolymph, or BAW feces extract released significantly smaller amounts of terpenes than did seedlings placed in BAW regurgitate. These results indicate that the active components are present in relatively large concentrations in regurgitate and that they are not related to the food source. Furthermore, regurgitate from several other species of caterpillars (Spodoptera frugiperda, Helicoverpa zea, Trichoplusia ni, and Anticarsia gemmatalis) as well as from the grasshopper Schistocerca americana induced the release of significant amounts of terpenes in corn seedlings. The release of these volatiles, therefore, appears to be a general response to attack by phytophagous insects. The terpene-releasing corn seedlings were highly attractive to the generalist parasitoid Cotesia marginiventris and to the specialized parasitoid Microplitis croceipes. This study confirms a systemic herbivore-elicited release of terpenes in corn. It is proposed that such chemicals serve multifunctional purposes that directly and indirectly protect plants against herbivorous arthropods and pathogens.
(The abstract is excluded from the Creative Commons licence and has been copied with permission by the publisher.)
Link to article at publishers website
Database assignments for author(s): James H. Tumlinson, Ted C.J. Turlings, Philip J. McCall
Research topic(s) for pests/diseases/weeds:
environment - cropping system/rotation
resistance/tolerance/defence of host
Research topic(s) for beneficials or antagonists:
environment/habitat manipulation
