ABSTRACT. The secondary screwworm, Cochliomyia macellaria (Fabricius) (Diptera: Calliphoridae), is a carrion-breeding species of veterinary, medical, and forensic importance. It is very abundant in the Nearctic and Neotropical regions and is one of the most common colonizers of vertebrate remains in the southern United States. Therefore, it is of great evidential value in estimating the minimum time of colonization (TOC) of remains related to forensic investigations. So far, studies have investigated the effects of several biotic and abiotic factors on C. macellaria. However, no data on the specific impact of food source moisture on the larval development of this species are known to have been published. In this study, the effects of diet moisture on larval development time, larval length, and weight over time, as well as adult emergence and weight were investigated. Cochliomyia macellaria was reared on diets prepared from freeze-dried bovine liver with varying moisture content (0.0, 33.0, 50.0, or 70.8 %) at 25.6 °C, 77 % RH, and 14:10 L:D. Frozen-thawed liver was used as a control. Water content was found to significantly impact immature development time and corresponding life-history traits, both within and among developmental stages of C. macellaria. This result indicates moisture content of the carrion source should be considered when estimating time of colonization and identification of immature stage of flies in forensic investigations. Furthermore, as diet moisture content significantly affected the dry mass of emerging adults, the mass of adults collected at a crime scene could provide useful information as it could be an indicator of the condition the remains were in during time of colonization, including the moisture content of the tissue. Forensic entomology, secondary screwworm, time of colonization, larval development

ABSTRACT. Wingbeat frequency and harmonics are being used to successfully identify agricultural pests and disease vectors in the field. This method is a viable alternative for identifying the forensically important blow fly (Diptera: Calliphoridae). The use of morphometric features and DNA to identify blow flies is difficult, time consuming and expensive, and are complicated by changes in species distribution and the appearance of invasive and hybrid species. Blow flies are the first to colonise decomposing remains and are ubiquitous. They provide valuable evidence when calculating time since death, as the development of the blow fly is highly predictable when using temperature and experimental reference data for the correctly identified species. However, species misidentification results in significant errors in estimating the time since death, as different blow fly species often have different developmental times and life history traits. Wingbeat frequency is measured using an optical sensor to record light fluctuations produced by the wings of an insect partially blocking the light when it flies between a laser beam and a phototransistor array. These fluctuations are then analysed by a classification model built and trained using a machine learning algorithm to identify each specimen by species and sex. This method enables the unbiased identification of an adult blow fly species with a reportable potential rate of error. The adult blow fly is the most mobile stage of the life cycle, determining the species’ presence in a decomposing community, and the speed at which it arrives. However, its role has been largely overlooked with much of the research being focused on the larvae. Flying adult flies are also difficult to study due to their small size and speed. The use of wingbeat frequency data to track and identify blowflies in real time will enable the research of arrival patterns of adult blow flies and the factors that influence detection and acceptance of a site for oviposition, by using a staged crime scene involving decomposing remains. Preliminary testing of common species belonging to the Lucilia and Calliphora genera has so far produced noisy, yet promising classification data. It is believed that by adjusting the placement of the sensor, a smoother signal will be produced, and the identification of each species will be possible. Flying insects have evolved to identify and communicate with each other by using their specific wingbeat frequency, and this offers a unique and promising identification tool to the already busy but often challenging field.

ABSTRACT. The estimation of the time since death (minimum Post Mortem Interval, minPMI) is an essential aspect to a forensic investigation, and this is particularly complex when a body is found in a marine environment, submerged, floating or beached. The estimation of the minPMI of a body found on land is generally based on the presence of carrion insects (Diptera: Calliphoridae; Sarcophagidae; Muscidae). In the marine environment, beside the minPMI, the time spent by the body underwater (minPMSI, minimum Post Mortem Submersion Interval) or floating (FI, Floating Interval) are necessary for a correct crime scene reconstruction. The presence of barnacles (Crustacea: Cirripedia) is one parameter that has come under recent scrutiny because of their colonisation and permanent settlement on human remains and their accompanying items, such as clothing and shoes. However, research in this field to present day is limited and focused in USA and Europe, and has not considered human clothing materials (fabrics). This research is focused on the colonisation – settlement preference and growth – of barnacles on cotton, velvet, satin and neoprene. Polystyrene floats (PFs), covered by the four types of fabric, were submerged over a period of six months off the coast of Perth, Western Australia. The aims of this research were 1) the identification of marine species colonising the fabrics, with special attention to barnacles; 2) the identification of which fabric provides the most desirable environment for colonisation; and 3) the identification of which factors affect the growth rate of the different species. Three species of barnacles (Balanus trigonus Darwin, Amphibalanus reticulatus (Utinomi) and A. variegatus (Darwin)) were present in varying amounts and sizes. The colonisation process of the barnacles happened rapidly, with colonisation observed in within the first month on neoprene. Statistical analyses were used to determine statically significant relationships between the barnacles’ number, diameter and distribution, compared to the type of fabric. Overall, the favourable substrata for this research were neoprene, followed by satin. Cotton, instead, showed a low colonisation, possibly due to the partial deterioration of the material over time. In contrast, velvet showed an inconsistent colonisation rate. The settlement preference observed was on the bottom half of the floats (away from sunlight exposure) and areas where the fabric creased. This study is the first to provide data to support the estimation of PMSI of clothed bodies that can be found in Western Australian marine waters.

ABSTRACT. Blow flies (Calliphoridae) are important medically and economically, and are commonly used in forensics as temporal markers in death investigations. While phenotypic traits in adult flies can be sexually dimorphic, sex identification in immatures is difficult. Consequently, little is known about how sex may result in developmental disparities among sexes even though there are indications that they may be important in some instances. Since genetic mechanisms for sex are well studied in model flies and species of agricultural and medical importance, we exploit the sex-specifically spliced genes transformer (tra) and doublesex (dsx) in the sex determination pathway to optimize a sex identification assay for immatures. Using known primer sets for tra and with a novel one for dsx, we develop PCR assays for identifying sex in four forensically relevant Calliphoridae species: Lucilia sericata (Meigen), Lucilia cuprina (Wiedemann), Cochliomyia macellaria (Fabricius) and Chrysomya rufifacies (Macquart) and evaluated their performance. Band detection rates were found to range from 71-100%, call rates ranged from 90-100%, and no error was found when bands could be called. The developed assay will assist in further differentiating sexually dimorphic differences in development of the Calliphoridae and aid in predicting more accurate estimates of insect age when age predictive markers (size, development time, molecular expression) are sexually dimorphic.

ABSTRACT. Various environmental factors can affect the duration of dipteran life cycles, a cycle important in forensic entomology when determining the time of colonization, which could be a time of death estimate. The amount of sunlight a carrion receives can influence the magnitude of presence of Diptera. In order to investigate, FTD2 disposable fly traps were used in lieu of carrion and were placed in direct sunlight and under shade for a total of 5 days between approximately 0700 and 1730. Diptera were collected and counted daily. Monitors of Ambient Light Intensity (MALI) sensors were used to determine the amount of sunlight a trap received by counting pulses of light outside a preset lux meter minimum or maximum. Shaded traps collected higher numbers of flies as time progressed while traps placed in direct sunlight collected fewer. A Fisher Exact test was used, and it was determined that there was a statistically significant trend that the flies preferred the shaded traps over the sunlit. Further trials and emphasis on ultraviolet radiation could be beneficial in determining a more statistically significant trend.

ABSTRACT. As a patchy and finite resource, carrion's availability and distribution are unpredictable in space and time. Some factors that can influence the availability and production of carrion include predation, old age, and anthropogenic causes. There are at least 11 blow fly species in SW Ontario, all requiring carrion resources for immature larval development yet manage to co-exist on what has been stated to be a rare, patchy ephemeral resource. My thesis will be testing the hypothesis that carrion resources are not as rare as previously considered and may be predicted using land-use attributes. More specifically, I will be using geospatial technology to model land-use attributes in the urban and rural areas of Essex County, Ontario. Some distinct elements of land-use being examined include farm, residential, commercial, waste, and conservation. These land-use locations are all predictors of carrion availability because a large majority of the meat produced globally is wasted during consumption and animal production. Other distinct elements that will be used to predict carrion availability include roadkill and traffic volume data. Following this, sites will be randomly chosen using a stratified random sampling approach to trap blow flies across the gradient of land-use predicted to influence carrion availability. This can further allow us to measure blow fly species diversity along this gradient. Looking at these same predictors we can also study blow fly species availability and diversity across a temporal scale such as seasonal. This knowledge furthers our understanding of blow fly co-existence across a spatial and temporal landscape.

ABSTRACT. Species of Diptera are studied across the world to help further understand patterns and habits so the behavior can be applied in forensics. In this study, habitat preference for various types of forensically important Calliphoridae, Muscidae, and Sarcophagidae were studied. A coastal habitat and an inland habitat were compared. Fly trap bags using putrescent egg solids and water were set up at inland and coastal habitats. The flies were analyzed and identified from the traps. There were 16 specimens of Calliphoridae, twelve Sarcophagidae specimen, and seven Muscidae specimen. Members of the Sarcophagidae were more prevalent at the coastal habitat, while members of Muscidae and Calliphoridae were significantly more prevalent at the inland habitat (p=0.004).

ABSTRACT. Many disciplines utilize phenology models, with the forensic sciences being among the most dedicated to the accuracy and precision of model output. Model output depends on many factors including error in parameter estimation and quality of input data. Model output also depends critically on model form, which depends on modeling approach. We take an approach that combines mechanistic and phenomenological elements on purpose, with the primary objective of developing models that perform well at prediction. We focus on blow fly species of forensic relevance, adapt heat-driven phenology models to improved input data, and simultaneously estimate model parameters that are typically estimated asynchronously: the slope of the function relating heat accumulation to development, and the lower thermal threshold or asymptote at which development rate reaches or approaches zero. We also incorporate behavioral thermoregulation into candidate models, and explore ways in which this incorporation not only enhances output of species-wise descriptions, but can enhance investigators' work by informing species choice for optimal post-mortem interval estimation in varying situational context.

ABSTRACT. Estimating time of death is an important aspect of forensic investigations. Models exist to estimate the minimum post-mortem interval, primarily on the basis of the development and phenology of forensically relevant organisms. However, these models implicitly assume that the thermal experience of large and often diverse Calliphorid populations is homogeneous at a given locale, failing to account for substantial spatiotemporal variability in the landscape and the blow flies’ ability to exploit this variability. Exploitation of thermal and other environmental variability by blow flies via behavioral thermoregulation has been substantiated in laboratory and field studies in many systems. Such studies indicate that blow flies’ experience is not stochastic with respect to environmental heterogeneity; it is structured. Here, I demonstrate consequences of these factors using simulation models, and show that to predict the phenology of a blow fly population capable of regulating thermal experience, we must understand spatiotemporal thermal variation in blow flies’ habitats, and the mechanisms through which blow flies exploit and are otherwise affected by this variation. Initial results focus on thermoregulation. The consequences of thermal landscape structure are also addressed.

ABSTRACT. The growth and development of insects are heavily temperature dependent. Generally, development time decreases as temperature increases, up to an optimal temperature. Beyond the optimal temperature, development and performance slow until a knockdown temperature or critical thermal maximum (CTmax) is reached, or enough time is spent at stressful temperatures, resulting in death. The same applies to extremely low temperatures, resulting in knockdown at the critical thermal minimum (CTmin). This research focuses on two forensically important blow flies, Chrysomya rufifacies (Macquart) and Cochliomyia macellaria (Fabricius) (Diptera: Calliphoridae). Both flies are currently found in Texas; C. macellaria is a native species, while C. rufifacies is an invasive species from the Eastern Hemisphere. Chrysomya rufifacies is predatory and has been known to displace other species of blow flies. It was hypothesized that C. macellaria would be outcompeted by the invasive predatory species, but it remains after 30 years. It is thought that temperature could play a role in their interactions and coexistence, as they originate from thermally unique regions. Temperatures in Texas can exceed 40˚C, which often results in maggot die offs. Texas does occasionally reach freezing temperatures, though this is more frequently experienced in these species’ northern ranges. Cooler temperatures are thought to be the limiting factor of the C. rufifacies invasion into the northern United States and Canada. The purpose of this research is to gain insight into the coexistence of these two species, and determine their CTmax and CTmin, using the ramping method, for four different larval stadia (1st instar, 2nd instar, feeding 3rd instar, and post-feeding 3rd instar).

Ames C., & Turner B. (2003). Low temperature episodes in development of blowflies: implications for postmortem interval estimation. Medical and Veterinary Entomology 17(2) 178-186.

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Faris, A. (2017). Studies on Variation in Texas Blow Flies (Diptera: Calliphoridae). Doctoral dissertation, Texas A&M University.

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ABSTRACT. Blow flies have an exceptional ability to locate and colonize dead and decomposing remains. Therefore, they are regularly used in death investigations to estimate forensically important timelines, such as the time of colonization as related to the postmortem interval. However, several factors may prevent blow flies from immediately colonizing said remains, ranging from blocked access to environmental temperature. Through two experiments, we investigated the effects of temperature on oviposition behavior for two blow fly species regularly used in casework. The first experiment exposed blow flies to constant temperatures ranging from 10 – 44.5°C in controlled laboratory settings to quantify both the lower and upper critical temperatures for oviposition. Cochliomyia macellaria oviposited from 15.0 – 44.5°C, though eggs only hatched and survived to adult emergence from 17.5 – 40.0°C. Chrysomya rufifacies oviposited from 22.5 – 42.5, though again eggs only hatched and survived to adult emergence from 22.5 – 37.5°C. The second experiment placed blow flies on a thermal gradient that ranged from 10 – 50°C and quantified the oviposition temperatures selected (i.e., preferred) by each species. The thermal preference for Cochliomyia macellaria oviposition was 35.9 ± 4.0°C (mean ± SD), while the thermal preference for Chrysomya rufifacies oviposition was 37.7 ± 1.9°C. The ranges for both the critical and preferred temperatures for oviposition fall within the broader critical temperature ranges for locomotion of both species. This suggests that while these species can physically reach a dead body, they may delay their oviposition if environmental temperatures are suboptimal. Any delay in oviposition affects estimates of forensically important timelines. Therefore, we encourage forensic entomologists to continue investigating the thermal biology of oviposition and to build temperature threshold datasets for oviposition much in the way they have amassed development data sets.

ABSTRACT. Dr. Fitzpatrick with provide our Keynote Presentation on Secondary Trauma in the Forensic Sciences.

ABSTRACT. An introduction to the new Journal of Forensic Entomology.

ABSTRACT. Carrion typically passes through six “stages” as it decomposes. These stages can be classified as: fresh, bloated, active decay, advanced decay, dry, and remains. Progression through these stages is thought to be partially governed by microbial and insect activity in association with other biotic and abiotic factors. During this process, volatile organic compounds are produced as a by-product of microbial metabolism and cell autolysis, which are partially responsible for bloat and can serve as primary cues regulating blow fly (Diptera: Calliphoridae) attraction, colonization, and utilization of carrion resources. However, studies using vertebrate remains (especially human) usually require the remains to be stored (i.e., refrigerated or frozen) before experiment initiation. Such practices alter the microbiome, and therefore possibly blow fly attraction. The first experiment presented here determined the effect of different storage methods on the attraction of a primary colonizer to the remains. Chicks were culled and preserved in a refrigerator (-4ºC) or freezer (-20ºC) for less than 24 hr before experiment initiation. A dual-choice cube olfactometer was used to determine preference of adult Cochliomyia macellaria (Diptera: Calliphoridae) when given the choice of previously frozen or refrigerated chicks. Of the flies that responded, 80% chose the previously frozen chick versus the refrigerated chick. Freezing carcasses can lead to a decrease in microbial activity and induce cell lysis, leading to a different decomposition pattern and alter primary colonizer attraction (e.g., greater attraction to previously frozen carrion rather than fresh carrion). A secondary study was conducted to determine if completely removing microbes affected the decomposition of vertebrate remains. Axenic and non-axenic mice were allowed to decompose in a controlled environment to assess the stages of decomposition. The bloat stage of decomposition was absent in the axenic mice as well as earlier fluid purge. These two studies expand on the role microbes play in decomposition and the attraction of a primary colonizer. Furthermore, the second study is the first of its kind to completely exclude microbes from the decomposition process and determine the impact on blow fly attraction and colonization.

ABSTRACT. Every year, hundreds of people die from controlled substances. As with many deaths, the deceased is not always found immediately. Forensic entomology has assisted the law enforcement community to determine the postmortem interval of the deceased. The development rate of the blow flies is vitally important to this determination. However, external influences can cause this rate to increase or decrease. One of these factors is controlled substances. With thorough research in a natural setting within forensic entomotoxicology, a better understanding of the effects of controlled substances on the growth and development can be gained. The more the forensic entomology community knows about influences of controlled substances on maggot growth and development, the more accurate the postmortem interval will be.

Five pigs were injected with morphine along with five control pigs being injected with a needle only for five days prior to being euthanized. All ten pigs were allowed to decompose as naturally as possible, in an open field with no vegetation coverage with open exposure to solar radiation. Dipteran larvae were collected in a way that would be comparable to collections at a crime scene. The initial decomposition rate was faster among the treated pigs as compared to the control pigs. The larval lengths of individuals belonging to forensically important family, Diptera: Calliphoridae, were not significantly different between the treated and control pigs, in 1st, 2nd, and 3rd instars on days three, six, and ten.

ABSTRACT. A long standing complication of using insect growth in estimation of time of colonization for decedent's whose deaths are caused by accidental overdose, has been the impact of these substances on maggot size. Studies have suggested increased or decreased length depending upon the toxic substance or the species of insect. In this presentation the lengths of 3rd instar fly larvae collected in forensic entomology casework associated with accidental deaths resulting from either trauma or toxic effects of: ethanol, cocaine, opiates, methamphetamine and barbiturates and three different body regions (upper body, lower body, off body) were compared. The results are complicated by normal growth patterns but suggest differences among drugs and fly species.

ABSTRACT. In many species, females alter factors surrounding oviposition behaviour (e.g. clutch size, timing of oviposition etc.) in response to novel conditions (Jaenike 1978). This is an example of behavioural plasticity. These behaviours are associated with the detection and acceptance of a suitable medium. I am testing the response of three species of blow flies (Lucilia sericata Meigen, Phormia regina Meigen, and Calliphora vicina Robineau-Desvoidy) to four differing profiles of volatile organic compounds placed on an agar medium. These organic compounds were deemed to be attractive to blow flies (Kadota, & Ishida, 1972; Kim et al., 2007; Richardson, 1966; Wang et al., 2001). Each volatile organic compound is associated with the breakdown of one amino acid (Liu et al., 2014). Each profile of volatile organic compounds corresponds to a diet lacking one essential amino acid (either phenylalanine, tryptophan, valine, or methionine). The resulting oviposition behaviour including choice of medium will be followed throughout this experiment. If blow flies choose one medium over another, that may indicate a preference based on what blow flies perceive to be a favourable diet medium. Flies may also present altered behaviours when detecting a suitable medium over a less suitable one. Early results indicate that blow flies may have a preference as to diets with profiles of different volatile organic compounds (VOC’s).

References: Jaenike, J. (1978). On optimal oviposition behavior in phytophagous insects. Theoretical Population Biology, 14(3), 350-356. doi:10.1016/0040-5809(78)90012-6 Kadota, H. and Y. Ishida, Production of volatile sulfur compounds by microorganisms. Annual Review of Microbiology, 1972. 26: p. 127-138. Kim, J., O.J. Che, and W. Park, A green fluorescent protein-based whole-cell bioreporter for the detection of phenylacetic acid. Journal of Microbiology and Biotechnology, 2007. 17(10): p. 1727-1732. Liu, W. (2014). Chemical and Nutritional Ecology of Lucilia Sericata (Meigen) (Diptera: Calliphoridae) as related to Volatile Organic Compounds and Associated Essential Amino Acids. Retrieved April 1, 2019. Petzold, A., Binder, M. D., Hirokawa, N., Windhorst, W., & Hirsch, M. C. (2009). Neuronal Cell Death and Axonal Degeneration: Neurofilaments as Biomarkers. SpringerReference. doi:10.1007/springerreference_117458 Richardson, M., Studies on the biogenesis of some simple amines and quaternary ammonium compounds in higher plants: isoamylamine and isobutylamine. Phytochemistry, 1966. 5(1): p. 23-30. Wang, D., X. Ding, and P.N. Rather, Indole can act as an extracellular signal in Escherichia coli. Journal of Bacteriology, 2001. 183(14): p. 4210-6.

ABSTRACT. Blow flies are usually the first insects to arrive at a carrion and use the carrion to oviposit or breed. For females, that means when and where she oviposits will impact the survival and fitness of her future offspring. The behaviour to search and accept a carrion for oviposition are influenced by abiotic factors, especially temperature and relative humidity (RH). Each species of blow flies has its own temperature-dependent growth rate, as well as thresholds for oviposition behaviour. Additionally, RH should influence site selection and egg aggregation by female flies. These behaviours are also influenced by interactions with other insects, which may be beneficial or detrimental. In this study, we evaluate how RH and conspecific/ heterospecific interactions will affect oviposition preferences, specifically, choices in the timing of oviposition, clutch size, and temperature preference chosen within a temperature gradient. Using Lucilia sericata Meigen, Phormia regina Meigen, and Calliphora vicina Robineau-Desvoid, individual females from each species are released into an arena on a temperature gradient, where they will choose their preferred temperature to oviposit in either high or low humidity. Cameras are placed to record their movement and behaviour and once females have oviposited; pictures are taken to estimate clutch size using ImageJ. Preliminary data shows that for L. sericata, there appears to be a difference in eggs laid between low and high humidity on the temperature gradient. There is also a difference in first oviposition timing, where females are ovipositing faster in high humidity in comparison with low humidity. For C. vicina, there appears to be no preference between humidities to oviposit. Surprisingly, females are ovipositing faster in low humidity in comparison with high humidity. Understanding oviposition behaviour in blow flies reduces reliance on assumptions about blow flies colonization, leading to more accurate estimates of time of death.

ABSTRACT. Estimation of the time of colonization (TOC) is often based on laboratory studies that document arthropod de-velopment. Precise data for forensically important species, such as blow flies (Diptera: Calliphoridae), are essential for accuracy in the estimate of TOC. Calliphorid development is a quantitative trait and thus depends on a host of variables. In calliphorids, studies showed photoperiod can play a role in development. However, there has been little research to date on the effects of photoperiod, and available data indicate the impact is species-specific. In this study, the effects of photoperiod on the development of Chrysomya rufifacies (Macquart), were examined. Chrysomya rufifacies is a fly of great medical and legal importance and is often encountered on vertebrate remains in temperate and tropic regions throughout the world, including North and Central America, Asia, and Australia. Larvae were reared under light regimes of 12, 16, and 24 h of light at 28.5 ± 0.0°C, 86.2 ± 0.3 RH. Minimum development time for each stage did not differ significantly for the applied photoperiods, nor were there significant differences in total minimum postembryonic development time. Photoperiod did not significantly affect larval size or growth rate. The data suggest that light durations investigated in this study do not influence the development of C. rufifacies. This indicates that photoperiod may not be a concern for forensic entomologists in Texas, United States, or other areas with similar conditions when estimating the TOC for this species. Validation efforts are encouraged to verify this conclusion.

ABSTRACT. Carrion is typically a non-replenishing, spatially, as well as temporally variable source of concentrated nutrition. Invertebrates and vertebrates intensely compete for these resources due to their value. Ecological studies of dipterans relying on these resources have primarily focused on insect-insect interactions despite their intense competition with vertebrates. The objective of this study was to demonstrate the impact vertebrates scavenging different species of small carrion (e.g., rat and broiler chick) with different coat colors (white, brown, yellow) across habitat type (open vs wooded), and season (winter vs summer) on the carrion utilization and reproductive success of blow flies, which are the key invertebrate decomposers of these resources. Vertebrate scavengers consumed all carrion during the winter; however, during the summer only 69% of the carrion was removed by vertebrate scavengers. Two blow fly species colonized the carrion regardless of type or habitat during the summer, 95% of blow flies (Diptera: Calliphoridae) were Lucilia eximia with the remaining being Chrysomyia rufifacies. Zero carrion was colonized during the winter, as it was all consumed, and up to 25% during the summer depending on habitat and carcass type. In open habitats, rat carrion was colonized 12.5% more than chick carrion indicating potential carrion preference or inability of vertebrates to locate the resource before blow flies. Further evidence supporting these conclusions was that a 22% greater preference for brown rats in wooded habitats than carrion with conspicuous coat colors. With regards to reproductive success, vertebrate scavenging prevented blow fly production during the winter due to complete removal of the carrion sources, while during the summer 16-50% remained available to colonize. However, while not a primary objective of the study, data on fly interactions (e.g., competition, predation) with fire ants (Solenopsis invicta) (Hymenoptera: Formicidae) determined that during the summer, blow fly access to carrion not scavenged by vertebrates was reduced by as much as 40%. When blow flies were able to colonize in the absence of fire ants, reproductive output was 80% greater. In conclusion, abiotic and biotic factors impacting blow fly reproductive output and carrion selection vary across carrion type, season, and habitat. Given anthropogenic effects (e.g., urban sprawl) in combination with the introduction of invasive species, such as the fire ant, as well as climate change, changing landscapes in which these insects reside potentially are experiencing selection, if one assumes historically they had access to all carrion not used by fire ants) for their utilizing unique resources derived from human activity (e.g., garbage) by these insects is possible. Such ecological shifts could impact their ecological services (e.g., nutritional flow to higher trophic levels, pollination).