Biology subjects

Durosaro, S. O.

Publications and source records attributed to Durosaro, S. O..

3 recordsLinked to original sources

bioRxiv2026

Standardized Protocols for Global and Local Thermal Nociception in Black Soldier Fly (Hermetia illucens; Diptera: Stratiomyidae) Larvae

Nociception, the capacity to detect tissue-damaging stimuli such as noxious chemicals or high heat, is increasingly studied across insect orders and life stages, informing our understanding of its adaptive value and molecular mechanisms. The black soldier fly (Hermetia illucens; Diptera: Stratiomyidae) is widely recognized as the star of the growing insects as food and feed industry. Black soldier fly larvae (BSFL) are reared at high densities that, combined with their extraordinary metabolism, can generate lethal overheating on farms. Data on the thermal nocifensive capabilities of BSFL could inform our understanding of larval behaviors during overheating events (and potential welfare impacts of thermal slaughter), and provide a comparative datapoint to the well-studied vinegar fly (Drosophila melanogaster; Diptera: Drosophilidae). Accordingly, we adapted global and local thermal nociception methods from larval vinegar flies for use with BSFL. We find that global assays (akin to boiling) adapt easily to both first and late instar BSFL, that BSFL exhibit slightly different nocifensive behaviors than last instar vinegar fly larvae, and that BSFL have higher thresholds (thrashing begins at 39.70 C in late instar BSFL versus 26.6 C in D. melanogaster). In contrast, the classical local nociception assay did not adapt easily to BSFL, so we modified the assay to test a time-bounded, continuous exposure to the temperature probe instead of response-latency. This assay generated a unique, gradual pattern of increasing responsiveness to the probe in late instar BSFL (>95% responsiveness above 66 C) rather than the sharp cutoff in responsiveness at 52 C demonstrated in D. melanogaster during response-latency assays. Altogether, these protocols open the door for standardized research on BSFL thermal nociception for fundamental and applied purposes.

animal behavior and cognition↗

bioRxiv2025

High protein diets early in life improve survival, reduce cannibalism, and increase growth and yield in farmed yellow mealworms

In the wild, animals may be able to compensate for nutritional inadequacies through foraging for novel resources; however, on farms, animals have more limited nutritional options. Therefore, providing adequate and accessible nutrition is essential to positive farmed animal welfare. Billions of yellow mealworms (Tenebrio molitor; Coleoptera: Tenebrionidae) are farmed as mini-livestock each year for use as food and feed. The major feedstock used, wheat bran, can sustain complete development of the species, but has been shown to have significantly lower protein content than yellow mealworms would typically self-select, particularly at early developmental stages. This can reduce growth, survival, and adult oviposition, and may contribute to high rates of cannibalistic behaviour among larvae (as larvae may have few options but to seek protein from the bodies of conspecifics). In this study, we use 20% nutritional yeast as a dietary protein supplement for larvae in early (0-4 weeks) and later life (4-8 weeks) to assess the effects on survival, growth rate, and rates of cannibalism, as well as any effects on growth, development timing, and adult body size. We also investigated the impact of this higher protein diet, when fed to either larvae or adults, on fecundity. We find that protein supplementation in larval diets increased survival by 23%, growth rate by 200%, and total biomass at eight weeks by up to 272%. Larval cannibalistic behaviour was reduced and development time was shorter. The high protein diet, whether fed to adults or to larvae, increased the number of offspring per female by 34-36%. Survival and growth benefits of protein supplementation were especially pronounced when fed to early juvenile instars, but can benefit mealworms across the entire first eight weeks of development. We highlight the need for further research into dietary protein supplementation for yellow mealworms across development to better align with their dietary choices, thereby improving fitness, yield, and welfare.

zoology↗

bioRxiv2025

Pupation substrate and prepupal handling affect eclosion rate, timing, and adult morphology in black soldier flies (Hermetia illucens; Diptera: Stratiomyidae)

On farms, the conditions experienced by black soldier fly (BSF) prepupae may impact their development and survival, altering production goals by changing the fitness of breeding adults. Few studies have addressed the impact of environmental variables (such as substrate type or moisture content), or stressors like handling, on the development and survival of BSF as they transition from prepupae through adulthood. This study examined the effects of pupation substrate (corn cob grits, potting soil, vermiculite, wood chips, and frass), moisture content (20%, 60%, and 100%), and handling during the prepupal period (daily handling, no handling) on eclosion rate and timing, morphology (mass, head width, thorax length), and abdominal window fullness of adult BSF. Handling delayed adult emergence by over three days, reduced eclosion rates by 30.6%, reduced head width and wet mass in adult males, and reduced window fullness and head width in adult females. Frass resulted in the lowest eclosion rate (72.1 {+/-} 2.4%) while corn cob grits (82.2 {+/-} 2.3%) and wood chips (81.5 {+/-} 2.2%) had the highest. Wood chips also resulted in the highest wet and dry mass, head width, and thorax length for adult males and females. Wood chips may be the best pupation substrate for BSF as it enhances body size and has a good eclosion rate. Significant prepupal handling delays adult emergence, reduces eclosion/survival rates, and reduces adult body size; however, more research is necessary to determine if the less chronic handling regimes that are likely present on farms produce similar effects.

zoology↗