Making optimal oviposition decisions is especially important for female carrion colonizing insects whose larvae often depend on ephemeral resources. Optimal oviposition theory predicts that females should exhibit behaviors that will maximize the performance of their offspring. Oviposition can be influenced by a variety of factors, including temperature. The aim of this study was to investigate the effects of temperature on the oviposition behavior and egg load of two blow fly species native to southern Ontario: Phormia regina Meigen, and Lucilia sericata Meigen (Diptera: Calliphoridae). Using fetal pig carcasses as an oviposition substrate, we assessed the length of time until the first oviposition event, preferred oviposition sites, and the total number of eggs oviposited. For each of the two species, five different temperature treatments ranging from 15 to 35°C were used. Temperature influenced time to the first oviposition event, as well as the number of eggs deposited by L. sericata and P. regina. As temperature increased, oviposition occurred faster with more eggs deposited for these two species. Female P. regina, in particular, demonstrated a higher egg load with increasing temperature. Differences in optimal temperatures for reproduction, including egg load and oviposition, may be a mechanism driving seasonal temporal resource partitioning leading to species coexistence utilizing ephemeral resources.

Estimates of the minimum post-mortem interval (mPMI) using the development rate of blow flies (Diptera: Calliphoridae) are common in modern forensic entomology casework. These estimates are based on single species developing in the absence of heterospecific interactions. Yet, in real-world situations, it is not uncommon to have 2 or more blow fly species developing on a body. Species interactions have the potential to change the acceptance of resources as suitable for oviposition, the timing of oviposition, growth rate, size and development time of immature stages, as well as impacting the survival of immature stages to reach adult. This study measured larval development and growth rate of the blow flies Lucilia sericata (Meigen, 1826), Phormia regina (Meigen, 1826) and Calliphora vicina Robineau-Desvoidy (Diptera: Calliphoridae) over five constant temperatures (15, 20, 25, 30, 35 °C), in the presence of conspecifics or two-species heterospecific assemblages. Temperature and species treatment interacted such that L. sericata larvae gained mass more rapidly when in the presence of P. regina at 20 and 30 °C, however only developed faster at first instar. At later stages, the presence of P. regina slowed development of L. sericata immatures. Development time of C. vicina immatures was not affected by the presence of P. regina, however larvae gained mass more slowly. Development time of P. regina immatures was faster in the presence of either L. sericata or C. vicina until third instar, at which point, the presence of L. sericata was neutral whereas C. vicina negatively impacted development time. Phormia regina larvae gained mass more rapidly in the presence of L. sericata at 20 °C but were negatively impacted at 25 °C by the presence of either L. sericata or C. vicina. The results of this study indicate that metrics such as development time or larval mass used for estimating mPMI with blow flies are impacted by the presence of comingled heterospecific blow fly assemblages. As the effects of heterospecific assemblages are not uniformly positive or negative between stages, temperatures or species combinations, more research into these effects is vital. Until then, caution should be used when estimating mPMI in cases with multiple blow fly species interacting on a body.

Understanding the biodiversity and distribution of forensically relevant blowflies (Diptera: Calliphoridae) in a region can aid in legal investigations when insects are associated with remains. For this purpose, we conducted a 14-month-long blowfly survey at the Anthropology Research Facility (ARF) of the University of Tennessee in Knoxville, Tennessee. Traps baited with pork kidney were deployed for 24 h twice a month throughout the study. A total of 3180 adult blowflies were collected, comprising 13 species from 7 genera. Phormia regina (Meigen) and Lucilia coeruleiviridis (Macquart) were the predominant species collected from this survey, with collections representing 65.9% and 20.6%of total flies captured, respectively. In addition to relative abundance, we investigated blowfly community composition, species abundance, richness, and diversity by season. One state record was identified, with adult Protophormia terraenovae (Robineau-Desvoidy) being collected for the first time in Tennessee. Additionally, an earlier record of Chrysomya megacephala (Fabricius) in Tennessee was noted. These findings can be used to aid in legal investigations in the area and surrounding areas where work is limited, as well as to provide information on which forensically relevant species should be the subject of future research in the area.

As educators who teach about sexual violence and victimization in our criminal justice and forensic science courses and a psychology undergraduate who was learning about these topics, we were curious whether and how the hashtag #MeToo is changing classroom dynamics. We examine two trauma informed education activities used in classes at two different universities to assess students’ attitudes towards learning about violence and victimization in the #MeToo era. Data come from students’ reflections on content warnings and engagement with potentially upsetting or even triggering material at the beginning and end of an online Criminal Justice course (N = 31) and reflections on a guest speaker who shared the on-going trauma of an unsolved homicide of a family member in a Forensic Science course (N = 90). Qualitative data revealed that even students who experience discomfort see the benefits of being exposed to sensitive material, such as increased empathy, feeling more prepared to interact with victims and/or their families, understanding the emotional tolls of working in the field, and feeling more prepared for jobs in criminal justice and forensic agencies.

Blow flies (Diptera: Calliphoridae) can detect decomposing remains and begin colonizing the resource through oviposition soon after. The estimated time between colonization and insect evidence collection is referred to as the time of colonization (TOC). Forensic entomologists use the TOC to help estimate the minimum postmortem interval (mPMI), or the time between death and the discovery of remains. The presence of insecticides can influence blow fly behaviors, including oviposition. This study aimed to investigate how different concentrations of two insecticides, bifenthrin and clothianidin, affected blow fly oviposition both under laboratory and field conditions. In the laboratory experiments, Lucilia sericata (Meigen) and Phormia regina (Meigen) blow flies were exposed to beef liver treated with varying concentrations of bifenthrin or clothianidin. In the field, stillborn pig carcasses were treated with the same concentrations and time to oviposition was assessed and oviposition site preference observed. Insecticides have the potential to deter insect activity. Therefore, we hypothesized that insecticide exposure would result in delayed oviposition, altered site preferences, and increased mortality due to their modes of action. Statistical analyses indicated that the insecticides had no significant effects on the time to oviposition in the laboratory experiments, although species‐ and insecticide‐specific effects were observed. Clothianidin, however, significantly affected mortality rates in both species. During field trials, bifenthrin significantly delayed oviposition, while clothianidin inhibited oviposition at the high concentration. These findings offer valuable insights for improving entomological evidence analysis in criminal investigations where insecticide exposure is suspected.

Blow flies (Diptera: Calliphoridae) can be used in forensic entomology to provide information, including an estimate of the time of colonization and minimum postmortem interval, based on insect development. This study examined the development of third instar Calliphora terraenovae Macquart in four substrates: pine shavings, soil, sand, and clay. Pupation time, survival to adult, and wing vein length were measured to examine the substrate influence. There was a significant difference in the time to pupation (F_3,36 = 11.87, p < 0.0001) and the number of flies that eclosed (F_3,36 = 4.716, p = 0.007) among the substrates. Blow flies pupated faster in pine shavings and eclosed as adult flies faster in sand than in other substrates. Adults eclosed in the sand in 21.9 days, followed by pine shavings (22.8), clay (24.2), and soil (26.6). Although overall survivorship was low (10–46%), the greatest number of flies eclosed in sand, and the fewest in clay. Understanding the factors that impact blow fly development can help forensic entomologists improve rearing protocols and apply this information to death investigations, especially in cases with buried remains.