| Title: | Methyl jasmonate induction of cotton: a field test of the 'attract and reward' strategy of conservation biological control |
| Author(s): | Williams L; Rodriguez-Saona C; Castle Del Conte SC; |
| Address: | "USDA-ARS, U.S. Vegetable Laboratory, 2700 Savannah Highway, Charleston, SC 29414, USA. Rutgers University, Philip E. Marucci Blueberry and Cranberry Research Center, 125a Lake Oswego, Chatsworth, NJ 08019, USA. 22604 SR 195, Pullman, WA, USA" |
| ISSN/ISBN: | 2041-2851 (Print) 2041-2851 (Electronic) |
| Abstract: | "Natural or synthetic elicitors can affect plant physiology by stimulating direct and indirect defence responses to herbivores. For example, increased production of plant secondary metabolites, a direct response, can negatively affect herbivore survival, development and fecundity. Indirect responses include increased emission of plant volatiles that influence herbivore and natural enemy behaviour, and production of extrafloral nectar that serves as a food source for natural enemies after their arrival on induced plants. Therefore, the use of elicitors has potential for the study of basic aspects of tritrophic interactions, as well as application in biorational pest control, i.e. an 'attract and reward' strategy. We conducted a field study to investigate the effects of methyl jasmonate, an elicitor of plant defence responses, on three trophic levels: the plant, herbivores and natural enemies. We made exogenous applications of methyl jasmonate to transgenic cotton and measured volatile emission, extrafloral nectar production and plant performance (yield). We also assessed insect abundance, insect performance, and parasitism and predation of brown stink bug, Euschistus servus, eggs in methyl jasmonate-treated and untreated control plots. Application of methyl jasmonate increased emission of volatiles, in particular, (+)-limonene and (3E)-4,8-dimethyl-1,3,7-nonatriene, and production of extrafloral nectar, but not yield, compared with the control treatment. Despite increased volatile and extrafloral nectar production, methyl jasmonate application did not affect plant bug performance, or mortality of E. servus egg masses, and only marginally influenced insect abundance. Mortality of E. servus eggs varied over the course of the study. Overall, methyl jasmonate treatment affected cotton plant-induced responses, but not the insects that inhabit the plants. Our results were probably influenced by reduced natural enemy colonization of cotton from adjacent non-crop habitats, and subsequent low within-field population recruitment. Much remains to be learned about the effects of exogenous application of plant-produced 'enhancers' on the behaviour of natural enemies before crop physiology can be manipulated to enhance pest control" |
| Keywords: | Cotton Euschistus servus Platygastridae extrafloral nectar methyl jasmonate parasitism plant bugs plant volatile induction predation stink bugs; |
| Notes: | "PubMed-not-MEDLINEWilliams, Livy 3rd Rodriguez-Saona, Cesar Castle Del Conte, Sandra C eng England 2017/09/13 AoB Plants. 2017 Jul 17; 9(5):plx032. doi: 10.1093/aobpla/plx032. eCollection 2017 Sep" |
