Effect of temperature on the oviposition and egg hatching performance of Alphitobius diaperinus (Panzer) (Coleoptera: Tenebrionidae)

The commercial accessibility of insect biomass for food and feed necessitates a systematic examination of the various factors that can potentially hinder the efficiency of insect farming. This study focuses on identifying the optimal thermal requirements for the lesser mealworm, Alphitobius diaperinus (Panzer), an edible insect species of particular interest due to its significant potential as a food and feed source. Adults of the species were left to oviposit continuously for 45 days, under controlled laboratory conditions at 20, 25, 30 and 32 °C. The number of eggs laid by the adults, as well as the larval emergence was recorded during this period. Based on the findings, the reproduction output, expressed as the cumulative number of eggs per adult and the cumulative larval hatching rate, was affected by the temperature levels tested here. It has been determined that the optimal reproductive output of A. diaperinus can be attained by maintaining newly emerged adults within a temperature range of 25 to 30 °C for a period of 42 days. During this period, it is anticipated that each adult will yield an average of 73 eggs, while an estimated hatchability rate of 69 and 58% at 25 and 30 °C, respectively. Our study is one of the few that evaluate the efficacy of retaining parental adults of A. diaperinus for oviposition under commercial mass-rearing conditions, taking into account egg and larval production.