Black Soldier Fly Reproduction under Different Adult Densities and Light Regimes

The black soldier fly (BSF) <i>Hermetia illucens</i> L. (Diptera: Stratiomyidae) has been recognised as a promising insect species for sustainable management of organic waste and by-products. Indoor breeding of BSF with artificial lighting has been proved successful, but efforts are still needed to efficiently maximise BSF indoors’ reproductive output. Increasing adult density seems a viable option to exploit the limited space constraint under indoor breeding, whereas decreasing artificial lighting duration may reduce unnecessary power consumption. This study aimed at investigating the effects of adult density (370, 926, and 1852 pairs/m³), light regime (8L : 16D, 12L : 12D, and 16L : 8D), and their possible interactions, on some BSF life history traits that are relevant to BSF reproduction. The results show that the overall BSF reproductive output increased with increasing adult density, but was not affected by light regime <i>per se</i>. With a BSF adult density of 1852 pairs/m³, a hatchling production of 7.5 × 10⁵/m³ was achieved within 10 days. At the highest adult density, increasing photoperiod increased hatchling production, but also decreased the number of hatchlings per watt used for artificial illumination. The temporal oviposition patterns, individual female reproductive output, mating success, egg hatching rate, and insect survival rate were not significantly affected by adult density or light regime as simple effects. However, the interaction between adult density and light regime was significant for the first oviposition peak, individual female reproductive output, and insect survival rate. The possible mechanisms behind our results are discussed.

黑水虻（black soldier fly, BSF）<i>Hermetia illucens</i> L.，隶属于双翅目（Diptera）水虻科（Stratiomyidae），已被公认为在有机废弃物与副产物的可持续管理领域极具应用前景的昆虫物种。当前采用人工光照的黑水虻室内繁育技术已取得成功，但仍需进一步优化以高效提升室内繁育条件下黑水虻的繁殖产出。提升成虫密度似乎是破解室内繁育空间限制的可行方案，而缩短人工光照时长则可降低不必要的电力消耗。本研究旨在探究成虫密度（370、926、1852对/立方米）、光照制度（8L:16D、12L:12D、16L:8D）及其潜在交互作用对与黑水虻繁殖相关的若干生活史性状的影响。研究结果显示，黑水虻的总繁殖产出随成虫密度升高而提升，但光照制度本身对其无显著影响。当成虫密度达到1852对/立方米时，10天内可实现每立方米7.5×10⁵头初孵幼虫的产出。在最高成虫密度组中，延长光照周期虽可提升初孵幼虫产量，但会降低单位人工照明功率对应的初孵幼虫数量。单一因素分析表明，成虫密度与光照制度均未对产卵时间模式、单雌繁殖产出、交配成功率、卵孵化率及昆虫存活率产生显著影响。但成虫密度与光照制度的交互作用对首次产卵峰值、单雌繁殖产出及昆虫存活率存在显著影响。本研究还对上述结果背后的潜在作用机制进行了探讨。