Growth response to population density in larval stage of darkling beetles (Coleoptera; Tenebrionidae) Tenebrio molitor and Zophobas atratus

Evaluation of Organic Wastes as Substrates for Rearing Zophobas morio, Tenebrio molitor, and Acheta domesticus Larvae as Alternative Feed Supplements

“…At the age of 66 days, the highest mean weight of A. domesticus reared on chicken feed was 0.512 g, whereas this decreased to 0.346 and 0.356 g, respectively, when reared on 90% cattle and horse manure. The increase in weight over time in response to chicken feed diet was comparable to the findings of Lundy and Parrella [17] at the same larval age. Collavo et al [42] recorded a mean weight of 0.452 g for A. domesticus at the same age when reared on a human refuse diet, whereas Lundy and Parrella [17] recorded considerably lower values in response to food waste diets.…”

“…The increase in weight over time in response to chicken feed diet was comparable to the findings of Lundy and Parrella [17] at the same larval age. Collavo et al [42] recorded a mean weight of 0.452 g for A. domesticus at the same age when reared on a human refuse diet, whereas Lundy and Parrella [17] recorded considerably lower values in response to food waste diets. Vaga et al [43] reported up to an 80% difference in the weight of A. domesticus fed a control diet containing 19.2% crude protein and 37.6% starch, and a red-clover-based diet.…”

“…In this study, T. molitor and Z. morio did not show a considerable increase in mortality when reared on low-protein diets. The growth rate, biomass accumulation, and population viability were strongly determined by food substrate composition in A. domesticus, and the N concentration explained 68% of the variation across treatments, whereas the ratio of N-to-acid detergent fibre explained another 28% of the overall treatment variability [17]. The mass of Z. morio and A. domesticus increased more than that of T. molitor, although the weight of the same number of A. domesticus larvae was significantly lower than that of T. molitor on day 1 of the experiment.…”

“…Zaelor and Kitthawee [17] evaluated the effect of larval density on productivity in T. molitor and Z. morio, and reported that the mixture of wheat bran and ivy gourd leaves was not an ideal diet for rearing either species. Lundy and Parrella [18] demonstrated that unprocessed and lower-quality organic side-streams, including post-consumer food waste, could not support the adequate growth and survival of A. domesticus populations.…”

The Superworm, Zophobas morio (Coleoptera:Tenebrionidae): A ‘Sleeping Giant’ in Nutrient Sources

“…Although high growth rates have been reported for Z. morio larvae ( Zaelor and Kitthawee 2018 ), these are reduced under crowding conditions ( VandenBrooks et al 2020 ). Cannibalism occurs often in Z. morio ( Tschinkel 1981 , Ichikawa and Kurauchi 2009 ), negatively affecting biomass production and yield, although it does not appear to be density-dependent ( Zaelor and Kitthawee 2018 ). Moreover, when talking about commercial large-scale production, care should be taken to avoid disease outbreaks that could totally devastate the insect cultures.…”