Biology subjects

Rollinson, L. N.

Publications and source records attributed to Rollinson, L. N..

3 recordsLinked to original sources

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↗