Plant Traits in Fig as Indicators of Resistance to Shoot Borer, Dyscerus? Fletcheri Marshall (Coleoptera: Curculionidae)

Abstract

A comparative study was conducted on fig (Ficus carica L.) cultivars Deanna and Poona to test whether antixenosis due to plant traits was at least partially responsible for a differential susceptibility to the shoot boring curculionid weevil, Dyscerus? fletcheri. Field evaluation revealed significant difference in borer incidence in cvs. Poona (6.25%) and Deanna (75%). Further, traits of plant architecture such as number of primary/ secondary/ terminal shoots, plant vigour and density of terminal shoots were significantly higher in cv. Deanna, which was highly susceptible to shoot borer. However, latex-flow index was significantly higher in cv. Poona that was resistant to the borer. A step-wise multiple regression analysis revealed that the tested plant traits explained 60% of the total variation in stem borer infestation (y=-0.96-0.02x1+0.23x2-0.03x3+0.24x4+1.28x5-1.31x6, R2=0.60) in the susceptible cultivar, Deanna. Role of these traits in preference/non-preference of D. fletcheri for a cultivar is discussed.

Keywords

• Fig
• Ficus carica L.
• Resistance
• Cultivars
• Stem Borer
• Dyscerus? Fletcheri