Prediction Model Based on BP-ANN and PCA for the Peak Occurrence of Liriomyza Huidobrensis

Liriomyza huidobrensis （Blanchard） is an important vegetable pest of pathology. In order to improve the accuracy of prediction of Liriomyza huidobrensis and to control the Liriomyza huidobrensis effectively, this paper presents a new prediction model by principal components analysis （PCA） and back propagation artificial neural network （BP-ANN） methods. The historical data from 1999 to 2007 on population occurrence are analyzed in order to find out a non-linear relationship between the pest occurrence and the meteorological factors. And then by using analysis results, the prediction model of Liriomyza huidobrensis occurrence in Jianshui in Yunnan is built. The new model has successfully applied to verify the paddy stem borer population occurrence in 2006. Test results show that the new prediction model with BP-ANN and PCA can improve the prediction accuracy.

Feeding of pea leafminer larvae simultaneously activates jasmonic and salicylic acid pathways in plants to release a terpenoid for indirect defense

The pea leafminer,Liriomyza huidobrensis,is an important pest species affecting ornamental crops worldwide.Plant damage consists of oviposition and feeding punctures created by female adult flies as well as larva-bored mines in leaf mesophyll tissues.How plants indirectly defend themselves from these two types of leafminer damage has not been sufficiently investigated.In this study,we compared the indirect defense responses of bean plants infested by either female adults or larvae.Puncturing of leaves by adults released green leaf volatiles and terpenoids,while larval feeding caused plants to additionally emit methyl salicylate and(E,E)-4,8,12-trimethyl-1,3,7,11-tridecatetraene(TMTT).Puncturing of plants by female adults induced increases in jasmonic acid(JA)and JA-related gene expressions but reduced the expressions of salicylic acid(SA)-related genes.In contrast,JA and SA and their-related gene expression levels were increased significantly by larval feeding.The exogenous application of JA+SA significantly triggered TMTT emission,thereby significantly inducing the orientation behavior of parasitoids.Our study has confirmed that larval feeding can trigger TMTT emission through the activation of both JA and SA pathways to attract parasitoids;however,TMTT alone is less attractive than the complete blend of volatiles released by infested plants.