Studies on the development of oryzaephilus mercator (fauvel) and oryzaephilus surinamensis (L.). (coleoptera: silvanidae) on some tropical dried fruits under laboratory conditions

In this study, the development of the stored product pest species Oryzaephilus mercator (Fauvel) and Oryzaephilus surinamensis (L.) (Coleoptera: Silvanidae) on certain tropical dried fruits (pineapple, mango, banana) was investigated under laboratory conditions, and key biological parameters were determined. The experiments were conducted in climate chambers under controlled conditions of 27 ± 1 °C temperature, 70 ± 5% relative humidity, and a 16:8 h light:dark photoperiod. For each diet, five male and five female adults (i.e., five pairs) were placed in rearing containers. The adult insects used in the experiments were 0–15 days old. All containers were examined after 65 days. As a result of the study, the highest number of eggs was observed in O. surinamensis reared on dried banana (24.00 ± 2.44 eggs), whereas the lowest number of eggs was recorded in O. mercator reared on dried mango (0.57 ± 0.30 eggs). The highest larval number was found in O. surinamensis on dried mango (92.00 ± 8.21), followed closely by O. mercator on the same diet (90.86 ± 5.70), while the lowest number of larvae was recorded in O. surinamensis on dried banana (1.33 ± 0.42). The highest number of pupae was detected in O. surinamensis on dried mango (22.50 ± 1.75), followed by O. mercator on dried banana (16.29 ± 1.19), whereas the lowest number was recorded in O. surinamensis on banana (0.33 ± 0.21). Regarding adult emergence, the highest number of female individuals was found in O. mercator on banana (38.00 ± 4.19), while the lowest was in O. surinamensis on dried banana (3.67 ± 0.99). Similarly, the highest number of male individuals was observed in O. mercator on banana (35.86 ± 4.20), and the lowest in O. surinamensis on banana (4.83 ± 0.98). In terms of total fecundity, O. mercator showed the highest value on mango (167.43±9.44), and the lowest on pineapple (90.71±9.13). O. surinamensis reached the highest total fecundity on mango (177.00±5.79), and the lowest on banana (34.17±2.89). The highest mortality rate for O. surinamensis was observed on banana (25.86 ± 7.92%), whereas the lowest was on mango (1.51 ± 0.53%). For O. mercator, the highest mortality rate was also recorded on banana (4.63 ± 1.09%), and the lowest on mango (2.61 ± 1.17%). Pupal weights were measured regardless of sex, and no statistically significant differences were found among the diets for either species. Regarding food consumption, O. mercator exhibited the highest consumption on mango (1.6596 ± 0.0786 g), and the lowest on pineapple (1.5819 ± 0.1620 g). For O. surinamensis, the highest consumption was recorded on mango (1.4268 ± 0.0637 g), and the lowest on banana (0.3773 ± 0.0202 g). Concerning frass production, O. mercator produced the highest amount on banana (0.5089 ± 0.0658 g), and the lowest on pineapple (0.3074 ± 0.0254 g). In contrast, O. surinamensis produced the highest amount of frass on pineapple (0.2226 ± 0.0181 g), and the lowest on mango (0.0345 ± 0.0215 g). These results revealed that the biological development parameters of both species varied significantly depending on the species and the type of food source. Furthermore, dried banana was shown to be a highly suitable substrate for O. mercator, based on its high consumption and frass production, whereas it served as a limiting diet for O. surinamensis, as indicated by its high mortality rate and low consumption and frass output.