Quantitative chemical ecology of the lingonberry fruitworm, Grapholita libertina Heinr

• Main Author: Hillier, Neil Kirk
• Format: Thesis
• Language: English
• Published: Memorial University of Newfoundland 2001
• Subjects: Ripen; Newfoundland
• Online Access: https://research.library.mun.ca/8584/; https://research.library.mun.ca/8584/1/Hillier_NeilKirk.pdf

The lingonberry or partridgeberry, Vaccinium vitis-idaea L. var. minus Lodd, is a low-growing ericaceous shrub, which produces edible berries that ripen in Newfoundland in mid-September. Grapholita libertina Heinrich, the lingonberry fruitworm, is a tortricid moth whose larvae feed within the lingonberry fruit. -- The objectives of this study were to identify sex attractants for G. libertina and to evaluate its use in monitoring and controlling populations in wild Newfoundland lingonberry fields. A synthetic sex attractant was developed from among chemicals attractive to other Grapholita species and tested in 1997 to monitor G. libertina populations. Identification of this attractant led to a series of questions. Could this attractant prove useful in estimating future larval infestations? What would be the most effective delivery system for this attractant? Could field trapping accurately predict flight? How similar is the synthetic male attractant to the naturally occurring female produced pheromone? -- Field trials were conducted with the sex attractant in 1998, 1999 and 2000 to correlate the adult trapping rate with the subsequent densities of larvae and damaged berries to examine the effects of berry distribution and heterogenous vegetation coverage in the wild. Trials in 1999 were conducted to determine the most effective trap design for monitoring G. libertina. The efficacy of mass trapping using sex attractants of G. libertina was tested in 2000 as a potential control measure. In addition, information on population trends and phenology of G. libertina were examined through recording of the flight season, degree day accumulations and population size. Field-collected G. libertina were reared in order to identify the naturally occurring female sex pheromone. Solid phase microextraction was used to collect insect effluvia and gas chromatography-mass spectrometry attempted to identify pheromone components and relative amounts in the pheromone blend. -- The results of this study indicated that a blend of: 85% ...