Biology subjects

Lemke, N. B.

Publications and source records attributed to Lemke, N. B..

5 recordsLinked to original sources

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↗

bioRxiv2025

Temporal Trends: Phase-shifted time-series analysis reveals highly correlated reproductive behaviors in the black soldier fly, Hermetia illucens (Diptera: Stratiomyidae)

ENGLISH ABSTRACTFor those researching reproduction of the black soldier fly (BSF), finding meaningful correlations between mating and downstream reproductive fitness metrics, owing to complex reproductive behavior and physiology, has been challenging. On the one hand, mating is not necessarily deterministic of fertile eggs being produced, since females might lay unfertile eggs both before and after mating. But conversely, the process is not random either, since fertility is predicated on the exchange of gametes during mating. To investigate the relationship between mating and other reproductive metrics, a cross-correlation analysis between lagged time series was conducted on data previously collected during a semi-outdoor greenhouse experiment. This process compared the average percent correlation between un-lagged mating with oviposition in traps, oviposition outside traps, total weight of eggs deposited, and hatch rate, which were lagged 0 to 6 days. This revealed that average mating was 97.54% correlated with oviposition in traps lagged by 2 days. For oviposition outside of traps, total egg weights, and hatch rate, these were also [~]71.63% correlated, 60.29% correlated, and 75.16% correlated with mating respectively, which were optimized when the time series were lagged n = 3 days. These trends likely have a biological basis since flies decrease their reproductive activity as they expend energy and senesce, aligning with temporal patterns consistently observed during BSF rearing.

ecology↗

bioRxiv2025

Size-stabilized, Hypoallometric, Genitalia Determined for Male Black Soldier Fly, Hermetia illucens (Diptera: Stratiomyidae)

The black soldier fly, Hermetia illucens, is mass-reared throughout the world to convert organic waste into ingredients for pet and livestock feed, as well as frass and other biological products. To promote the optimization of breeding regimes carried out by industrial black soldier fly operations, it is critical to better understand adult reproductive anatomy and its potential relationship with fertile egg production. However, in this species, little is known about how reproductive anatomy changes with respect to increases in body size. Hence, this study investigated the nutritional static allometric relationship between the external genitalia of adult male black soldier flies and their body size. Size differences were induced top-down by increasing the larval rearing density, which has a negative effect on adult body size. For each of 3 rearing densities, a random sample of 30 adults was selected, and measurements taken three times each for the head, thorax, parameral sheath, and gonostylus. Fitting a generalized linear log-log model to the data revealed that for every 10.0% increase in body size (thorax length), genital length (parameral shealth) only increased by 1.8%. The resulting allometric slope of genitalia to thorax size was 0.195, indicating a pattern of hypoallometry. The presence of hypoallometric genitalia in a domestic population suggests individuals should be able to copulate regardless of differences in body size, which is consistent with most other insects. Moreover, this finding implies that black soldier fly genitalia were hypoallometric prior to their domestication and continues to persist within captive black soldier fly populations. To confirm, future work should investigate the direct impacts of hypoallometric genitalia on fitness, especially in flies which have been genetically edited or artificially selected to be increasingly large. LAY SUMMARYAdult male black soldier fly shown to have similar sized genitals despite differences in body size. SHORT SUMMARYThe black soldier fly, Hermetia illucens, is an economically important insect mass-reared throughout the globe; however, a large knowledge gap exists in terms of its reproductive anatomy and physiology. This study examined the relationship of male genitalia to body size, finding a 10% increase in body size corresponded with a 1.8% increase in genitalia size, meaning the structures are hypoallometric. This finding is important because it indicates large and small flies have similar sized genitalia, which may allow differently-sized individuals to copulate.

zoology↗

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↗

bioRxiv2024

Sex-specific perching: Monitoring of artificial plants reveals dynamic female-biased perching behavior in the black soldier fly, Hermetia illucens (Diptera: Stratiomyidae)

Artificial perches are implemented by many companies that mass-rear the black soldier fly, Hermetia illucens, to create a more natural breeding environment or provide additional surface area for flies to rest. However, basic information related to perching behavior is lacking. This experiment tested the effect of adding perches to breeding cages on fitness and behavior. Perches were constructed from artificial leaves affixed to wooden dowels inserted into foam blocks, placed in the center of cage floors. The four treatment-levels had an added surface area of 0.00-, 0.04-, 0.26-, and 0.34-m2. Each 0.93-m3 cage was supplied with 90 male and 90 female flies, and female thoraxes marked with acrylic paint. Beyond the tested range, a linear model suggests that 1.00-m2 additional surface area can accommodate a 1.46-fold increase in flies without negative fitness impacts. Time-series analysis revealed; (a) females utilized perches 1.42-times more often than males across two trials; (b) especially in the morning where the difference could be as high as 2.56-times more than males; (c) this decreased to 0.20-1.57 times more females than males by 1600 h, and (d) this cyclical pattern repeated each day throughout the week with decreasing female-bias, starting from 2.41-times more females on Day 1 to 0.88-1.98-times more females than males on Day 6. These dynamics are likely due to the presence of male flies engaging in aerial contests near lamps providing light needed for mating, especially during early hours and early adulthood, aligning with prior knowledge of black soldier fly mating behavior. LAY SUMMARYFemale black soldier flies perch on artificial plants much more often than males, especially early in the day and early in their reproductive lives, times when males are competing with one another in aerial swarms.

animal behavior and cognition↗