بررسی نقش دو ترکیب فرار گیاهی در شکار فرمونی ‭Spodoptera littoralis (Boisduval) (Lep.: Noctuidae) ‬در مزارع چغندرقند

The host plants play an important role in the pheromone-based communication of insects. They can modulate the biosynthesis or the release of pheromones and the response of the insect to the pheromones. Although sex pheromones are very active per se in moths recent data let us re-examine perception of sex pheromone by male moths in presence of and plant odour background, as a possible modulator of the response. Therefore we studied the effect of two volatile plant compounds on the pheromone-based field trapping of Spodoptera littoralis, a major pest in cotton, maize and sugar beet: 1) ( )-linalool, a monoterpene, released by intact host plants and after induction by herbivore action, particularly by the feeding of S. littoralis caterpillars and 2) cis-3-hexen-1-ol, a green leaf volatile which is a fatty acid metabolite whose emission increases under the feeding of insects. Both compounds have been shown to elicit responses from olfactory neurons in male S. littoralis. Experiment was conducted as a complete randomized block design with five replicates of each treatment in sugar beet farms in Khouzestan (late 2007) and Fars (July-September, 2008) provinces. The seven treatments were the synthetic pheromone, ( )-linalool, cis-3-hexen-1- ol alone and the binary and ternary combinations of pheromone with the plant volatiles. Green Funnel traps were used in the experiment. In Khouzestan, the number of moths captured in traps with pheromone plus ( )-linalool was 88% higher than in traps without ( )-linalool. Cis-3-hexen- 1-ol had no effect on the capture by the pheromone-baited traps. The traps baited with only plant volatiles captured only 4 moths on a total of 2046 in Khouzestan. Only male moths were caught by all traps. Results support the role of ( )-linalool as a sex pheromone synergist for the attraction of male S. littoralis to pheromone-based traps in Khouzestan conditions. Thus, addition of some plant compounds to synthetic pheromone blend might considerably enhance the efficiency of population monitoring or attract & kill method. The experiment will be completed in Fars province next. In Fars province, the tested plant volatile components didn't affect the trapping of male S. littoralis by pheromone traps due to the very low capture (only 229 insects). KEY WORDS Insects, Lepidoptera, Noctuidae, Spodoptera littoralis, Pheromone, Host plant volatiles, ( )-linalool, Cis-3-hexen-1-ol

کلیدواژه ها:

چغندرقند ، آفات ، اسپودوپترا لیتورالیس ، فرومون های جنسی ، روش های کنترل