Impacts of development and adult sex on brain cell numbers in the Black Soldier Fly, Hermetia illucens L. (Diptera: Stratiomyidae)  

The Black Soldier Fly (Hermetia illucens, Diptera: Stratiomyidae) has been introduced across the globe, with numerous industry applications predicated on its tremendous growth during the larval stage. However, basic research on H. illucens biology (for example, studies of their central nervous system) are lacking. Despite their small brain volumes, insects are capable of complex behaviors; understanding how these behaviors are completed with such a small amount of neural tissue requires understanding processing power (e.g. number of cells) within the brain. Brain cell counts have been completed in only a few insect species (mostly Hymenoptera), and almost exclusively in adults. This limits the taxonomic breadth of comparative analyses, as well as any conclusions about how development and body size growth may impact brain cell populations. Here, we present the first images and cell counts of the H. illucens brain at four time points across development (early, mid, and late larval stages,...黑水虻（Black Soldier Fly，*Hermetia illucens*，双翅目（Diptera）：水虻科（Stratiomyidae））已在全球范围内被引种，其幼虫阶段的极强生长特性支撑了诸多工业应用场景。然而，当前针对黑水虻生物学的基础研究仍存在大量空白，其中尤以其中枢神经系统相关研究为甚。尽管昆虫的脑容量极小，但它们能够展现复杂的行为模式；要阐明这些行为如何通过如此有限的神经组织得以实现，就需要探明大脑内的神经处理能力（例如细胞总数）。目前仅在少数昆虫类群（绝大多数为膜翅目（Hymenoptera））中完成了脑细胞计数，且研究对象几乎全部为成虫个体。这一现状不仅限制了比较分析的分类学覆盖广度，也使得我们无法就发育进程与体型生长如何影响脑细胞种群规模得出可靠结论。本研究首次呈现了黑水虻在整个发育周期内四个时间节点（幼虫早期、中期与晚期……）的脑部成像数据与脑细胞计数结果。