Influence of larval density, substrate moisture content and feedstock ratio on life history traits of black soldier fly larvae

Abstract

Performance and body composition of insect larvae depend on quality and quantity of their diet, and on biotic factors such as larval density. Experiments were undertaken to assess the effects of larval density, substrate moisture content and feedstock ratio on larval life history parameters of black soldier fly (BSF) in the laboratory. Four-day-old larvae were separately reared under six different densities (1, 2, 4, 6, 8 and 10 larvae/cm2) and at five substrate moisture content levels (40, 50, 60, 70 and 80%) obtained by moistening feed with fresh water. Five feedstock ratios of 25, 50, 100, 150 and 200 mg of feed per larva per day were also tested. Each treatment had four replicates and used commercial chicken feed as substrate. Results showed that individual larval feed reduction, wet weight, survival rate, body size and body thickness had a negative correlation with rearing densities, while larval development time correlated positively. The increase in substrate moisture content has significantly affected the larval feed reduction, wet weight, development time, body size and body thickness of the larvae. On the other hand, the survival rate was not significantly affected. The larvae subjected to diet 150 mg/larva/day showed a highest individual wet weight (0.19±0.003 g), body size (20.55±0.335 mm) and body thickness (4.982±0.081 mm). Their recorded development time was relatively short (11.25±0.500 days), compared to the other. The larval survival rate was not significantly affected by the feedstock ratio. This study indicates that larval life history parameters of BSF are influenced by the rearing conditions.

Feeding strategies for small-scale rearing black soldier fly larvae (Hermetia illucens) as organic waste recycler

“…BSF colony was established in 2017 from larvae of wild-trapped Hermetia illucens populations breed since 2016 at the International Institute of Tropical Agriculture (IITA), Yaoundé, Cameroon. BSF egg clusters from the pre-established colony were incubated according to the method described by Dzepe et al [9]. After hatching, a total number of 48 000 four-day-old larvae were collected and divided into two equal groups used to test two feeding strategies (continuous and batch feeding strategies).…”

“…Therefore, there is a pressing need for developing multiple potential food waste valorization technologies to reduce as well as mitigate the adverse effects of food waste. Processing of organic waste using fly larvae is a relatively new concept which is currently attracting interest [6][7][8][9].…”

The Digestibility of Banana Peel and Testa coconut and Its Effects on the Growth and Mortality of Black Soldier Fly Larvae (Hermetia illucens) at Constant Feeding Rates

“…This could explain why the pupation period of the larvae group fed with banana peels was shorter than the group fed with coconut testa based on the likelihood of getting sugar and protein. On the other hand, the water content of the banana peels had a higher positive effect on the process of the accumulation of nutrients during the larval stage to be used in the pupation period (Cheng et al, 2017;Dzepe et al, 2019).…”

Substrate as insect feed for bio-mass production

“…A further key issue in terms of efficiency and quality is the water content. A recent study (Dzepe et al, 2020) in which five substrates moisture content levels (40, 50, 60, 70 and 80%) were tested, indicated that increasing the substrate moisture content reduces the larval feed reduction (mass reduction, %; Salomone et al, 2017), wet weight, development time, and body size and body thickness of the larvae. This is in line with another study (Lalander et al, 2020), which reported that adding too much water content reduced the biomass conversion ratio and survival rate of the larvae.…”