Investigation of factors relating to the insect infestation of chocolate-based consumables

The aim of this study was to examine the factors relating to insect infestation of produce manufactured at the Cadbury Schweppes' Tasmanian confectionery plant, in order to determine means by which the incidence of product infestation could be minimized. Analysis of the company's infestation-related consumer complaint databases revealed that: assortments (boxed-chocolates) were most likely to be infested; the geographic distribution of complaints was temperature-dependent; 'old' stock and/or produce manufactured during spring was most likely to be infested; infested goods were more likely to be purchased from smaller retail outlets and; the costs associated with infestation were substantial. Phycitine moths were almost exclusively responsible for infestation, and it was estimated that most cases of infestation occurred post-packaging, most likely while stock was in the hands of independent wholesalers and retailers. A small proportion of infestation probably originated at the Hobart plant, caused by a resident population of the almond moth, Ephestia cautella (Walker). This population was traditionally suppressed by the blanket application of synergised pyrethrins throughout the factory, although, an extensive pheromone trapping program indicated that the spraying of pyrethrins affected neither the distribution of E. cautella, nor the capture rate, and the distribution of E. cautella within the factory was primary dependent upon hygiene conditions. A single room within the factory was identified as the primary source of migratory E. cautella, and a control strategy, based on the mass trapping technique, successfully reduced E. cautella numbers in this room to negligible levels. The influence of trap design on E. cautella catch was also evaluated. Aspects of phycitine ecology with regard to the post-packaging infestation of produce were examined, and it was found that both adult and juvenile phycitines responded positively to odours escaping from chocolate boxes. The integrity of packaging significantly influenced the likelihood, and extent, of infestation, while the polyvinyl chloride film used to overwrap assortment boxes was found to be readily penetrated by several stored-product insect species. An alternative polypropylene film offered significantly improved insect barrier properties. A number of measures aimed at minimizing both pre- and post- packaging infestation were recommended. At the factory, it was recommended that an insect pest control strategy relying on advanced insect detection methods and improved sanitary procedures, supported by an appropriate management structure, be adopted in preference to the current chemical-based strategy. With regard to post-packaging infestation, it was recommended that wholesalers and retailers be educated about the dangers that stored-product insects pose to goods, and methods through which insect apparency can be minimized. It was also recommended that the utility of packaging materials and/or technologies that completely retained odours and provide superior insect barrier qualities be investigated. Also, that quality control procedures be implemented to monitor the integrity of product packaging.