Mendoza, J. E. | bioRxiv Science

bioRxiv2025

Peas on Mars: A study of garden pea, Lathyrus oleraceus (=Pisum sativum), growth in Martian regolith simulant treated with black soldier fly frass

Future long-duration missions to Mars will require in situ food production systems to reduce dependence on resupply missions and enhance crew autonomy. This study evaluated the growth performance of peas, Pisum sativum, cultivated in Martian regolith simulant (MMS-1) ameliorated with black soldier fly, Hermetia illucens, (BSF) frass at inclusion levels of 0, 10, 25, and 50% by volume. Pea plant fitness was then assessed over the course of two, 8-week greenhouse trials by measuring germination rate, plant height, leaf chlorophyll content, and final dry biomass. These were compared against peas grown in a control substrate consisting of commercially available gardening soil treated with the same frass-inclusion percentages (0, 10, 25, or 50% by volume). Germination and height responses were statistically similar between regolith and soil, suggesting that properly amended regolith may be able to sustain in situ crop growth on Mars. Notably, peas grown in regolith simulant + frass exhibited slightly higher chlorophyll content than the controls, while biomass productivity was lower than commercial potting mix + frass when comparing across the same frass-inclusion percentage. These findings represent the first experimental evidence that BSF frass can enhance crop cultivation in a Martian soil analog, highlighting its potential role in bioregenerative life support systems and in-situ resource utilization (ISRU) strategies. In addition, fitting quadratic regression models to the data indicated an optimal frass inclusion between approximately 5-32% (depending on which metric was to be maximized), beyond which fitness declined. Beyond space applications, these findings build on prior studies by further supporting the value of insect-derived amendments for improving nutrient-poor or degraded soils. O_TBL View this table: org.highwire.dtl.DTLVardef@1a09584org.highwire.dtl.DTLVardef@1b82ec5org.highwire.dtl.DTLVardef@10692a6org.highwire.dtl.DTLVardef@86093corg.highwire.dtl.DTLVardef@1c84eb8_HPS_FORMAT_FIGEXP M_TBL O_FLOATNOTable 1:C_FLOATNO O_TABLECAPTIONGlossary of Acronyms and Initializations Used C_TABLECAPTION C_TBL

plant biology↗

bioRxiv2024

Heterogeny in cages: Age-structure and timing of attractant availability impacts fertile egg production in the black soldier fly, Hermetia illucens

Adult behavior is a growing area of interest for those researching the black soldier fly, Hermetia illucens (L.) (Diptera: Stratiomyidae), which is affected by underlying demography and spatiotemporal patterns. This greenhouse experiment examined the interaction of age-related effects that can accrue within heterogeneous breeding populations and the potential benefits of delaying an oviposition attractant in concert with restricting mean cohort age. The impetus for this investigation was because if flies are introduced into a mating-cage before old flies are removed or culled, this creates a population of mixed-age and mating-status. We hypothesized this potentially reduces quality among available mate choices, especially in small cages where flies might not be able to spatially segregate. Metrics for fitness included copulation frequency, oviposition frequency, weight of eggs produced, and hatch percentage. "Same"-aged cohorts (maximum 4-d-old at introduction) performed better than highly heterogeneous (1-16-d-old) "mixed" cohorts by mating 2.32-times more frequently and laying 6.58-times more eggs that were 1.17-times more fertile, despite 1.41 fewer observed oviposition events. Delaying the attractant had a significant effect on egg collection weight and led to 1.25-times higher egg yields for same- age populations compared to mixed-aged cohorts where the delaying the attractant had no significant effect. These results are likely due in part to an immediate desire to lay eggs by older females as well as haphazard egg laying in cage material, which was 2.09-times higher for mixed cohorts. The results highlight the importance of constraining the age of breeding populations and removing old adults from cages to improve yields and better manipulate behavior. For those for whom this is logistically unfeasible, providing an attractant box initially and continuously may be the preferred method to trap more eggs from heterogeneous populations.

ecology↗