Developing larvae of major insect pests like Ephestia cautella rapidly degrade stored cocoa beans through feeding and other biological activities on the beans. Completion of developmental stages of insects may be influenced by a number of biochemical factors triggered by the primary post-harvest processing of cocoa beans prior to storage. Hence, this study assessed the development of E. cautella from first instar larval stage to adult stage on cocoa beans fermented at varied degrees. Fresh ripening pods of Amelonado variety (N38) were harvested and fermented variedly at 0 -7 days, and sun-dried to about 5-6% moisture content. The variedly fermented cocoa beans (300 g/treatment) were infested with newly hatched first instar larvae of E. cautella (N=10) in a completely randomized design with four replications at 28±2°C and 70±5% relative humidity (RH). Days to adult emergence of the larvae of E. cautella on the cocoa beans varied significantly (P>0.05) between 0 day and 76.50 days in 4 days and 7 days-fermented beans, respectively. Significant variations occurred (P>0.05) in the total adult emergents of E. cautella, ranging between 0 and 8.25 in 4 days and 1 day fermented beans, respectively. This study reveals that the fermentation period of cocoa beans prior to drying and storage influenced adult emergence of E. cautella on stored cocoa beans, with 0 -3 days fermented beans highly susceptible to E. cautella's development to adult stage. Cocoa beans need to be fermented adequately for 4 to 7 days before drying to prevent insects' damage. Notably, 4-days fermented cocoa beans did not support E. cautella development to adult stage at 90 days post larvae-introduction. The 4-days fermented cocoa beans require further investigations for its nutritional suitability and importance in human diets.

Damage by the tropical warehouse moth, Ephestia cautella (Walker) to stored plant products especially dried cocoa beans is enormous. This is expressed in holing with frass and webbing of the beans leading to nutritional loss; turning the valuable commodity into powder and reducing the value in the export-import market. Effective management of the pest is contingent upon correct identification and bioecological expressions in relation with the host(s) and other environmental influences. Therefore, the morphological traits (phenotypic) variability between sexes and populations of E. cautella across different locations in Southwestern Nigeria were investigated with a view to identifying the population structure of E. cautella in the region. Thirty-two ecotypes of E. cautella (16 male; 16 female) populations (n = 10/ecotype) were evaluated for eight morphometric traits including forewings (length and width), hind-wings (length and width), body length, antenna length and abdominal dimension (length and width). Significant variations (P ≤ 0.05) occurred among the 32 E. cautella ecotypes for the eight measured traits with respect to sexes, locations and the interactions of the two sources of variation (sex by location). By magnitude, the females had significantly (P ≤ 0.05) higher mean for the fore and hind wings (length and width), body length and abdominal dimension; however, the antenna length was longer in males than in females' samples. The overall mean Gower genetic distance for the 32 E. cautella ecotypes was 0.656, with the range of 0.273 to 0.968. At 0.1 level of similarity index, four clusters (I, II, III, IV) emerged; with the membership of 7, 8, 12, and 5 respectively. This study showed that four ecotypes of E. cautella exist in southwestern Nigeria with sex by location assessment and this can be useful in control programmes of the pest.

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