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In forensic entomology, determining the age of a larva from a body to estimate time since death is commonly performed through the measurement of a physical trait. Gene expression has been studied as an alternative age estimation approach, but the storage conditions required for these studies are different than those used in forensic entomological casework. Studies analyzing gene expression prioritize the preservation of RNA, which requires fresh tissue and ultra‐cold storage. Casework, in contrast, utilizes hot water killing specimens that may not be analyzed for a long period after collection. In the current study, the impact of hot water killing on gene expression was assessed for larval samples of the forensically important blow fly, Cochliomyia macellaria. Successful amplification of the sex‐determining gene, transformer, was tested across larvae ranging in size from 3.22 to 16.85 mm in length after storage times of 1–2 weeks, 4–5 weeks, and 8–9 weeks at 4°C in RNAlater. Larvae hot water killed were processed in tandem with larvae stored live to allow for a direct assessment of the impact of boiling on gene expression. As expected, the transformer gene was successfully amplified in all larvae stored live. For the hot water‐killed larvae, the success rate was only slightly lower, with 3 out of 75 larvae not generating a sex‐specific band pattern. The results show gene expression can be used for hot water‐killed samples, though future work across different genes, species, and extending to quantitative gene expression methods is needed. [ABSTRACT FROM AUTHOR]

An uncommon case of forensic entomology applied to a roadkill animal is detailed; the minimum period of insect activity (PIAmin: 72 h) and the postmortem interval (PMI: ≤48 h) were calculated. Inferences and possible events pre- and postmortem are related and proposed, including the possible explanation of the occurrence of colonizer carrion flies on dry remains. The accelerating effect of vertebrate scavengers on the decomposition stages of the carcass was measured (7.4 time faster). This study is the first forensic entomology case applied to a roadkill animal in the neotropics.

There are certain morphological features and individual characteristics that are special to varying species that affect their lifecycle through every phase. Certainly, not every species will live for the same amount of time from emergence to death. In our case, there are two species of interest for our experiment. These two species are Chrysomya rufifacies (Diptera: Calliphoridae) (Macquart) and Cochliomyia macellaria (Diptera: Calliphoridae) (Fabricus). Both fly species have a detrimental impact on the livestock industry. They enjoy feeding on dead tissue after a sustained injury and are the cause of myiasis presence in several livestock species. For this reason, and many more, they are a concern economically. Through general observations, we have noticed that adult Chrysomya rufifacies appear to be much bigger than Cochliomyia macellaria adults are, and wondered if this meant there would be a distinction in longevity of adult life and if the variation in size is indicative of adulthood longevity. Wild maggots were obtained and raised on foodgrade bovine liver. The adults were given a sugar water mixture daily until death, in which the number of days lived by each adult was recorded. The data was analyzed using a T-test in SPSS. Analyzing the data this way allowed us to obtain and compare measurements of mean, standard deviation, standard error, and the P value. Our results indicate that Cochliomyia macellaria (p=.0467) adults live much longer than Chrysomya rufifacies adults do, and that size is not indicative of longer life. Further research is needed to evaluate varying results for these two species, as well as conduct new experiments with other forensically important insect species. [ABSTRACT FROM AUTHOR]

Research documenting insect colonization of human remains is limited in North America, and currently nonexistent for the American Midwest. Such research is essential for forensic entomologists to identify species of research interest in a region. In this study, we collected insects from human remains in 24 cases across Indiana from June 2016 through September 2018. We analyzed species composition across scene type and season. Eight species of blow flies were collected as larvae from human remains, with Phormia regina and Lucilia sericata as the two predominant colonizers. Phormia regina was the most numerous species collected from outdoor scenes (73.6% of total collections) while L. sericata was the most numerous from the indoor scenes (60.4% of total collections). With scene types pooled, Calliphora vicina and Cochliomya macellaria were the predominant species in the fall (55.6% and 42.2%, respectively); P. regina was the dominant colonizer in the spring (68.6%); and P. regina and L. sericata were the predominant colonizers (46.5% and 44.4%, respectively) in the summer. In addition to these findings, we confirmed the first record of Lucilia cuprina colonizing human remains in Indiana having collected this species from three cases. A single adult Chrysomya megacephala was collected from an indoor scene in southern Indiana, which represents its second collection in the state. Beetles belonging to the families Staphylinidae, Silphidae, Histeridae, Cleridae, Trogidae, Dermestdae, and Nitidulidae were also collected from two outdoor scenes. This study provides important baseline data for forensic entomologists in Indiana, as well as surrounding states with similar environments. [ABSTRACT FROM AUTHOR]

Se emplearon dos tipos de tejidos (hígado y corazón) de cerdo doméstico (Sus scrofa L), como cebos atrayentes para comparar la efectividad de los mismos para atraer insectos. En una trampa se colocaron 200 gr de hígado de cerdo, mientras que en la otra 200 gr de corazón. Se capturaron 2 285 especímenes los cuales están distribuidos en tres órdenes: Ocho familias de Diptera, incluyendo Calliphoridae con 2 001 ejemplares, Phoridae con 99 ejemplares, Muscidae con 82 ejemplares, Sarcophagidae y Drosophilidae con 37 y 25 ejemplares, respectivamente. Las especies más abundantes dentro del Orden Diptera fueron Chrysomya megacephala, Lucilia sericata, Cochliomyia macellaria, Chrysomya rufifacies Lucilia eximia y Lucilia cuprina.

Graphical abstract Highlights • The essential oil from Curcuma longa leaves is an industrial byproduct. • α-phellandrene was the major compound (41.99%) of C. longa leaves essential oil. • CLLEO and α-phellandrene were effective against Cochliomyia macellaria. • Cuticle, digestive tract, Malpighian tubules and brain damages were observed in C. macellaria larvae. • C. longa essential oil represents a suitable product to control livestock flies. Abstract Curcuma longa L., popularly known as turmeric, is one of the most studied Curcuma species due to its rhizome, wide used as a dye, and its multipurpose uses in medicine, cosmetics, food flavoring and textile industries. However, the knowledge of essential oils (EO) from C. longa leaves is still limited. In turmeric production, the stems and leaves above the ground are considered waste products after harvesting. The present study was designed to assess the chemical composition of C. longa leaves EO (CLLEO) and investigate the bioactivities of its major constituent, α- phellandrene against third instar larvae (L3) of Cochliomyia macellaria (secondary screwworm). In addition, we intended to demonstrate through ultrastructural and histological assessment the morphological damages in L3. Groups of 20 L3 were placed on filter papers impregnated with increasing concentrations (0.31 to 2.86 μL/cm2) of CLLEO, determining mortality after 6, 24 and 48 h of contact. The compound α- phellandrene represented 41.99% of the EO. Other compounds were: α -pinene, β-p inene, myrcene, ρ-c ymene, limonene and 1,8-cineole. The major compound of CLLEO, α- phellandrene was also tested (0.29 to 1.47 μL/cm2). C. macellaria mortality 48 h after contact with 1.27 μL/cm2 of CLLEO was 96.66 and 58.33% when using ethanol and acetone as solvents, respectively. The highest α -phellandrene dose assessed in this work (1.47 μL/cm2) presented a high mortality rate (96.66%). Structural analysis revealed marked lesions (cuticle surface dryness and severe degeneration on the spiracular plate) for both extracts. Histological sections of L3 showed necrosis of the intestinal tract and in the Malpighian tubules, and trophocytes with vacuolization. The brain had pyknotic profiles and vacuolar degeneration for both EO derivations. We suggest that CLLEO represents a sustainable bio-product for C. macellaria control that cause secondary myiasis to humans and animals. [ABSTRACT FROM AUTHOR]

Graphical abstract Highlights • Wound healing represents a neglected public health issue. • An alternative therapeutic approach for the treatment of wounds is presented. • The simultaneous use of MDT and some topical agents is one of the strategies to overcome the limitations of each therapeutic approach by itself. • The results obtained in this study showed that the combined use of larvae and hydrogel or 10% papain gel may be promising to maximize tissue repair. • Honey, EFA and collagenase could be used to prepare the bed of the dry wounds to receive the MDT. Abstract Wound healing is a complex process involving multiple biochemical and cellular events and represents a neglected public health issue. As a consequence, millions of people worldwide suffer from chronic wounds. The search for new treatment alternatives is therefore an important issue. In the context of wound healing, Maggot Debridement Therapy (MDT) is an inexpensive treatment with few contraindications and very promising results. This study aimed to evaluate the in vitro feasibility and implications of larvae (= MDT) use when combined with topical agents as a strategy to identify additive or synergistic combinations. The weight and survival rate of Cochliomyia macellaria (Fabricius) (Insecta, Diptera, Calliphoridae) larvae reared in an in vitro wound with either honey, hydrogel, 10% papain gel, essential fatty acids (EFA), collagenase, or silver sulfadiazine were evaluated after 24, 48 and 72 h. Hydrogel (for weight: 24 and 72 h; for survival: 24 h) and 10% papain gel (for weight: 48 h; for survival: 48 and 72 h) demonstrated the least interference in larval weight gain and survival rate, when compared to the control group. The results obtained in this study showed that the combined use of larvae and hydrogel or 10% papain gel may be promising to maximize the tissue repair. Honey, EFA and collagenase could be used to prepare the bed of the dry wounds to receive the MDT. [ABSTRACT FROM AUTHOR]

Depending on the species, males or females tend to exhibit increased longevity based on heterogametic chromosomes. While differences in longevity between males and females of a species has been extensively studied, differences in longevity between males of the same family has been minimally investigated. Longevity is crucial in understanding an insect’s physiology; it can affect developmental times and other life history traits. Cochilomyia macellaria and Chrysomya rufifacies are two Calliphoridae species that are known to cause myiasis, which is detrimental to the livestock industry. By determining the longevity of the adult C. macellaria and Ch. rufifacies males, it is possible to use the data to predetermine future myiasis outbreaks and take preventative action. Wild maggots from both species were reared and the longevity of emerging males was recorded. Results show that male C. macellaria adults lived an average of 27.79 ± 10.96 days, significantly longer than Ch. rufifacies adult males that lived an average of 21 ± 12.80 days (p=0.021). It is possible that the difference in longevity is due to mating; Ch. rufifacies mate sooner than C. macellaria, due to differences in female developmental time and longevity. [ABSTRACT FROM AUTHOR]

El estado físico en que se encuentra un cadáver presenta señales claras del tiempo que ha transcurrido, y esto asociado a la fauna que él mismo presenta puede ayudar a esclarecer el intervalo postmortem. En “Potrero Seco”, provincia de Chiriquí se descubrió un cadáver en estado avanzado de putrefacción, colonizado por larvas de moscas. Se colectaron las larvas al azar y se colocaron en cámaras de crías para permitir que continuaran su desarrollo en tanto que otras larvas fueron colocadas en alcohol al 70 % para detener su desarrollo. Las larvas más grandes tenían un tamaño de 12.0 mm, y este tamaño fue recuperado en larvas que tenían 168 horas de exposición. Esto se basó en el análisis del tamaño que tenían las larvas al momento que fueron recuperadas del cadáver. De acuerdo con el experimento, la especie que se recuperó del cadáver correspondió a Cochliomyia macellaria y su ciclo de vida demoró 24 a 26 días, desde la fase de huevos hasta la obtención de los ejemplares adultos.

Chrysomya rufifacies (Macquart) and Cochliomyia macellaria (Fabricius) are two important insects in the field of forensic entomology. Due to their tendency to immediately colonize a corpse after death, a comparison of sample flies taken off of a corpse and estimates of the duration of different parts of their life cycle is a valuable tool for determining the post-mortem interval (PMI) of a body. In order to accurately determine the PMI, the estimate for the duration of all of the insects' life stages must be as accurate as possible. Chrysomya rufifacies larvae, in addition to feeding on carrion, are also facultative predators of other insects, including C. macellaria larvae. This predator-prey interaction of these species on a corpse in the wild could affect the development time of one or both species, and one factor that could affect their interactions is the relative adult longevity of each species. Chrysomya rufifacies were observed to have a larger adult body size than C. macellaria, and this study was performed to determine if Ch. rufifacies also has a greater adult longevity than C. macellaria. The flies of both species, born of wild caught specimens, were reared in a laboratory, and the adult lifespans of the flies were measured. It was found that the C. macellaria adults had a mean lifespan of 27.133 days, and the Ch. rufifacies adults had a mean lifespan of 23.426 days, which is a significant difference (p< 0.05). [ABSTRACT FROM AUTHOR]

In the case of homicides, forensic entomologists are very useful for pinpointing the post mortem interval. In order to accurately do this, they must possess a thorough knowledge of the morphology of blow flies as well as blow fly development. This experiment studies the difference in pupal weight amongst and across the two species of Cochliomyia macellaria and Chrysomya rufifacies in order to have a comparison. Maggots were collected from carrion and allowed to pupate. Once the pupae emerged, their weights were documented. The blow flies were sexed once they had reached adulthood. It was found that both male and female Chrysomya rufifacies weigh more in the pupal stage than do their Cochliomyia macellaria counterparts and are larger in size. By using pupal weight to more quickly identify the species, forensic entomologists will ultimately be able to estimate a PMI in a more timely manner. [ABSTRACT FROM AUTHOR]

In forensic cases involving entomological evidence, establishing the postcolonization interval (post-CI) is a critical component of the investigation. Traditional methods of estimating the post-CI rely on estimating the age of immature blow flies (Diptera: Calliphoridae) collected from remains. However, in cases of delayed discovery (e.g., when remains are located indoors), these insects may have completed their development and be present in the environment as adults. Adult fly collections are often ignored in cases of advanced decomposition because of a presumed little relevance to the investigation; herein we present information on how these insects can be of value. In this study we applied an age-grading technique to estimate the age of adults of Chrysomya megacephala (Fabricius), Cochliomyia macellaria (Fabricius), and Phormia regina (Meigen), based on the temperature-dependent accumulation of pteridines in the compound eyes, when reared at temperatures ranging from 5 to 35°C. Age could be estimated for all species*sex*rearing temperature combinations (mean r2±SE: 0.90±0.01) for all but P. regina reared at 5.4°C. These models can be used to increase the precision of post-CI estimates for remains found indoors, and the high r2 values of 22 of the 24 regression equations indicates that this is a valid method for estimating the age of adult blow flies at temperatures ≥15°C. [ABSTRACT FROM AUTHOR]

Alternative methods for the identification of species of blow fly pupae have been developed over the years that consist of the analyses of chemical profiles. However, the effect of biotic and abiotic factors that could influence the predictive manner for the tests have not been evaluated. The lipids of blowfly pupae (Cochliomyia macellaria, Lucilia cuprina, Lucilia sericata, and Phormia regina) were extracted in pentane, derivatized, and analyzed by total-vaporization solid phase microextraction gas chromatography-mass spectrometry (TV-SPME GC-MS). Peak areas for 26 compounds were analyzed. Here we evaluated one biotic factor (colonization) on four species of blow flies to determine how well a model produced from lipid profiles of colonized flies predicted the species of flies of offspring of wild-caught flies and found very good species identification following 10 generations of inbreeding. When we evaluated four abiotic factors in our fly rearing protocols (temperature, humidity, pupation substrate, and diet), we found that the ability to assign the chemical profile to the correct species was greatly reduced. [ABSTRACT FROM AUTHOR]

Common forensic entomology practice has been to collect the largest Diptera larvae from a scene and use published developmental data, with temperature data from the nearest weather station, to estimate larval development time and post-colonization intervals (PCIs). To evaluate the accuracy of PCI estimates among Calliphoridae species and spatially distinct temperature sources, larval communities and ambient air temperature were collected at replicate swine carcasses (N = 6) throughout decomposition. Expected accumulated degree hours (ADH) associated with Cochliomyia macellaria and Phormia regina third instars (presence and length) were calculated using published developmental data sets. Actual ADH ranges were calculated using temperatures recorded from multiple sources at varying distances (0.90 m–7.61 km) from the study carcasses: individual temperature loggers at each carcass, a local weather station, and a regional weather station. Third instars greatly varied in length and abundance. The expected ADH range for each species successfully encompassed the average actual ADH for each temperature source, but overall under-represented the range. For both calliphorid species, weather station data were associated with more accurate PCI estimates than temperature loggers associated with each carcass. These results provide an important step towards improving entomological evidence collection and analysis techniques, and developing forensic error rates. [ABSTRACT FROM AUTHOR]

The most important contribution of forensic entomology is the estimation of the postmortem interval (PMI) or time since death. The forensic entomologist assumes that the biological clock of necrophagous insects that develop by feeding on cadaver tissues begins when the victim's biological clock is turned off. However, tissues can be invaded while the host is still alive (called myiasis), so the period of activity of necrophagous insects would not be indicative of PMI. The aim of this work was, through the presentation of a case report, to highlight the importance of expertise in the identification of necrophagous species associated with a corpse and their type of relationship in order to avoid an erroneous estimation of PMI. The corpse of a woman, missing for 14 days, was found outdoors in a small river 15 cm deep. Her corpse had numerous lesions infested with dipteran larvae that were collected during autopsy. Entomological evidence included second and third instar larvae of Cochliomyia hominivorax and Co. macellaria. The obligate parasitic nature of Co. hominivorax as a primary producer of myiasis and secondary of Co. macellaria allowed us to establish the time when the victim was still alive and from there to estimate the PMI. • The most important contribution of forensic entomology is the estimation of time since death. • The biological clock of necrophagous flies starts when the victim's biological clock shuts down. • Necrophagous species may invade host tissues while the host is still alive (called myiasis). • This work proves that the period of insect activity (PIA) in the presence of myiasis does not correspond to the PMI. [ABSTRACT FROM AUTHOR]

The family Calliphoridae is widely known to lead the colonization of corpses and their development rates are frequently used to estimate the postmortem interval. This study presents the larval growth of five forensically important species of Calliphoridae in Colombia. Rearing took place in semicontrolled field conditions where the egg masses were collected. We show curves of larval growth, larval length and time intervals to reach all immature stages for Lucilia eximia and Cochliomyia macellaria at two sites with different climatic conditions and for Chrysomya albiceps, Chrysomya megacephala and Calliphora nigribasis at one site. Overall, high temperatures speeded up the development of the species reared at two different sites, whereas low temperatures for C. nigribasis, lengthened the total development time. Differences between this study and others can be explained by the experimental conditions in the field without the possibility of strict laboratory rearing controls.La familia Calliphoridae es ampliamente conocida por liderar la colonización de los cadáveres y sus tasas de desarrollo son frecuentemente utilizadas para estimar el intervalo postmortem. Este estudio presenta el crecimiento larval de cinco especies de Calliphoridae de importancia forense en Colombia, considerando que la cría se dio en condiciones de campo semicontroladas en los lugares donde las masas de huevos fueron colectadas. Mostramos también, los intervalos de longitud y el tiempo empleado en alcanzar todos los estadios inmaduros para Lucilia eximia y Cochliomyia macellaria en dos lugares con diferentes condiciones climáticas y Chrysomya albiceps, Chrysomya megacephala y Calliphora nigribasis, en un solo lugar. En general, las altas temperaturas producen una aceleración en el desarrollo de las especies criadas en dos sitios diferentes, mientras que bajas temperaturas para C. nigribasis, alargaron el tiempo utilizado para completar el desarrollo. Las diferencias entre este estudio y otros, pueden estar dadas por las condiciones experimentales presentadas en campo sin los controles estrictos que son posibles durante la cría en laboratorio.

MicroRNAs (miRNAs) are small noncoding RNAs that modulate gene expression through post-transcriptional regulation. Here, we report the identification and characterization of miRNAs in two closely related screwworm flies with different feeding habits: Cochliomyia hominivorax and Cochliomyia macellaria. The New World screwworm, C. hominivorax, is an obligatory parasite of warm-blooded vertebrates, whereas the secondary screwworm, C. macellaria, is a free-living organism that feeds on decaying organic matter. Here, the small RNA transcriptomes of adults and third-instar larvae of both species were sequenced. A total of 110 evolutionarily conserved miRNAs were identified, and 10 putative precursor miRNAs (pre-miRNAs) were predicted. The relative expression of six selected miRNAs was further investigated, including miRNAs that are related to reproduction and neural processes in other insects. Mature miRNAs were also characterized across an evolutionary time scale, suggesting that the majority of them have been conserved since the emergence of the Arthropoda [540 million years ago (Ma)], Hexapoda (488 Ma) and Brachycera (195 Ma) lineages. This study is the first report of miRNAs for screwworm flies. We also performed a comparative analysis with the hereby predicted miRNAs from the sheep blowfly, Lucilia cuprina. The results presented may advance our understanding of parasitic habits within Calliphoridae and assist further functional studies in blowflies. [ABSTRACT FROM AUTHOR]

Blowflies (Diptera: Calliphoridae) are a family of much importance to the fields of forensic and medical entomology. Blowflies can find decomposing flesh within minutes and are an important species used by forensic entomologists in determining a post-mortem interval (PMI). PMI may be used to estimate a time of death for a given individual and is a very common practice in the field of forensics. This study measured the differences in longevity between adult male Chrysoma rufifacies and Cochliomyia macellaria flies. Maggots were reared in a laboratory in order to properly measure their lifespan. A t-test was done to determine a p-value for the given data. It was found that C. macellaria adult male flies (M=27.7931; SD= 10.962) experience a greater longevity than Ch. rufifacies adult male flies (M=21; SD=12.8027). This information can be applicable in determining post-mortem intervals in future forensic entomology cases and for use in secondary myiasis in medical settings. [ABSTRACT FROM AUTHOR]

Cochliomyia macellaria (Fabricius) (Diptera: Calliphoridae) is a significant species in forensic entomology when accurately determining time of death by using postmortem interval. The larvae participate in secondary myiasis when feeding on the decaying tissue of deceased organisms. Variables such as temperature and location can either speed up or slow down the development of C. macellaria, which need to be taken into account when determining an accurate time of death. Eggs of C. macellaria were collected, submerged in water for varying amounts of time, and observed in order to see if exposure to water caused them to die before hatching. It was found that eggs soaked for one minute had the highest percentage survive. Eggs soaked for zero, two, and five minutes had slightly less survive, while eggs soaked for seven and ten minutes saw a significant decrease in survival. These results will not only assist forensic entomologists when determining time of death, but will also give a better understanding about which habitats this species is most likely to be found in. [ABSTRACT FROM AUTHOR]

Many forensically important Calliphorids reap their importance from use of their relatively known development time. Both Chrysomya rufifacies and Cochliomyia macellaria are in the family Calliphoridae, and have been found to invade carcasses. This allows a postmortem interval (PMI) to be established, and this levies them forensic significance. If more points of comparison pertaining to elements of development or time lived of Ch. rufifacies and C. macellaria could be correctly utilized, then a more accurate PMI could be produced. In this study C. macellaria and Ch. rufifacies adults (F1) were reared from maggots obtained on a highway (P1) in order to record the length of time each individual F1 adult lived. The mean longevity of C. macellaria was found to be about four days longer than the longevity of Ch. rufifacies and showed no apparent positive correlation between observed general body size and the length of time an adult lived. [ABSTRACT FROM AUTHOR]

Comprehension of the lifecycle and life expectancy of Cochliomyia hominivorax Coquerel and Cochliomyia macellaria Fabricius, the primary and secondary screwworm, respectively have historically been of the utmost concern to researchers in medical, livestock and entomological research fields. C. hominivorax is a highly damaging agricultural pest because it is a prominent cause of myiasis in both humans and livestock, and attacks both living and necrotic tissue on the organism it infests. C. hominivorax has been eradicated in the United States, and the less dangerous Cochliomyia macellaria has taken the place of C. macellaria for research purposes given that the two species share similar life histories. In order to ensure that the use of C. macellaria as a model organism is valid, any potential differences in life history between the two species must be explored. This experiment was designed to determine lifespan differences between the sexes of C. macellaria, and results obtained showed no significant difference between the lifespans of males and females when exposed to laboratory conditions. Given this information, researchers can logically deduce that similar lifespans between the sexes are most conducive to maximized efficiency of C. macellaria. This information can then be taken and compared to similar studies in C. hominivorax to determine whether models of the life history of C. hominivorax based on C. macellaria are valid as they are, or if they need to be adjusted. [ABSTRACT FROM AUTHOR]

Cochliomyia Townsend includes several abundant and one of the most broadly distributed, blow flies in the Americas, and is of significant economic and forensic importance. For decades, Cochliomyia hominivorax (Coquerel) and C. macellaria (Fabricius) have received attention as livestock parasites and primary indicator species in forensic entomology. However, C. minima Shannon and C. aldrichi Del Ponte have only been subject to basic taxonomy and faunistic studies. Here we present the first complete phylogeny of Cochliomyia including numerous specimens per species, collected from 13 localities in the Caribbean. Four genes, the mitochondrial COI and the nuclear EF-1a, 28S rRNA, and ITS2, were analyzed. While we found some differences among gene trees, a concatenated gene matrix recovered a robustly supported monophyletic Cochliomyia with Compsomyiops Townsend as its sister group and recovered the monophyly of C. hominivorax, C. macellaria and C. minima. Our results support a close relationship between C. minima and C. aldrichi. However, we found C. aldrichi containing C. minima, indicating recent speciation, or issues with the taxonomy of the group. We provide basic information on habitat preference, distribution and feeding habits of C. minima and C. aldrichi that will be useful for future forensic studies in the Caribbean. [ABSTRACT FROM AUTHOR]

Bovine blood inoculated and incubated with bacteria was tested to determine if secondary screwworm, Cochliomyia macellaria (F.), would be attracted to the incubated substrate for oviposition. Five species of bacteria, Klebsiella oxytoca (Flugge), Proteus mirabilis Hauser, Proteus vulgaris Hauser, Providencia rettgeri Hadley, Elkins and Caldwell, and Providencia stuartii Ewing, previously isolated from animal wounds infested by primary screwworms, Cochliomyia hominivorax (Coquerel), were used. Incubated substrates were tested in a twochoice cage bioassay to study landing response and oviposition by gravid C. macellaria. Significantly more flies landed on substrates containing P. mirabilis than on substrates with other species of bacteria. Klebsiella oxytoca-treated substrates attracted the least flies. Substrates containing bacteria incubated for 72 h attracted significantly more flies than those incubated for 24-, 48-, or 96-h period. In 3-h duration oviposition tests, substrates with P. rettgeri attracted significantly more flies to oviposit than the other four species. The most eggs were recorded when substrates treated with all five species of bacteria were offered for oviposition. It is likely that multiple active chemicals present in the volatiles from substrates treated with all five species result in greater response than those in a single species. At least 72-h incubation seems to be necessary to obtain the most active volatile chemicals. Results suggest that C. macellaria uses similar chemical cues as C. hominivorax from bacteria volatiles as oviposition attractant/stimulant. [ABSTRACT FROM AUTHOR]

Understanding the onset and duration of adult blow fly activity is critical to accurately estimating the period of insect activity or minimum postmortem interval (minPMI). Few, if any, reliable techniques have been developed and consequently validated for using adult fly activity to determine a minPMI. In this study, adult blow flies (Diptera: Calliphoridae) of Cochliomyia macellaria and Chrysomya rufifacies were collected from swine carcasses in rural central Texas, USA, during summer 2008 and Phormia regina and Calliphora vicina in the winter during 2009 and 2010. Carcass attendance patterns of blow flies were related to species, sex, and oocyte development. Summer-active flies were found to arrive 4-12 h after initial carcass exposure, with both C. macellaria and C. rufifacies arriving within 2 h of one another. Winter-active flies arrived within 48 h of one another. There was significant difference in degree of oocyte development on each of the first 3 days postmortem. These frequency differences allowed a minPMI to be calculated using a binomial analysis. When validated with seven tests using domestic and feral swine and human remains, the technique correctly estimated time of placement in six trials. [ABSTRACT FROM AUTHOR]

This paper presents a diffusion model of larval dispersal especifically designed to account for particular aspects of postfeeding larval dispersal from the food source in organisms such as blowflies. In these organisms the dispersal of immatures includes two groups of individuals, those that are actively migrating and those that have initiated the pupation process. The classical diffusion equation in one dimension was modified to incorporate a function which describes the burying of larvae to become pupae. The analytical solution of this equation predicts oscillatory and monotonic dispersal behaviors, which are observed in experimental populations of blowfly species

The equilibrium dynamics of native and introduced blowflies is modelled using a density-dependent model of population growth that takes into account important features of the life-history in these flies. A theoretical analysis indicates that the product of maximum fecundity and survival is the primary determinant of the dynamics. Cochliomyia macellaria, a blowfly native to the Americas and the introduced Chrysomya megacephala and Chrysomya putoria, differ in their dynamics in that the first species shows a damping oscillatory behavior leading to a one-point equilibrium, whereas in the last two species population numbers show a two-point limit cycle. Simulations showed that variation in fecundity has a marked effect on the dynamics and indicates the possibility of transitions from one-point equilibrium to bounded oscillations and aperiodic behavior. Variation in survival has much less influence on the dynamics.

Cochliomyia macellaria (Fabricius) (Diptera: Calliphoridae), the secondary screwworm, is a medically and forensically relevant insect due to its infestation of necrotic tissue on cadavers and living organisms. Many insects exhibit sexual dimorphism in various traits, such as longevity, and these differences may be useful in making more accurate estimations of post-mortem interval (PMI). Male and female screwworms were reared from captured adults and their longevity was charted to determine differences between the sexes. However, it was determined that male and female C. macellaria exhibit no significant differences with regards to longevity and are similar to other carrion-feeding Diptera that are commonly found in cases of myiasis or cadaver infestation. This new data on longevity may be used in future research on the role C. macellaria plays in medical and forensic entomology. [ABSTRACT FROM AUTHOR]

Cochliomyia hominivorax and C. macellaria are species that cause primary and secondary myiasis, respectively of medical and veterinary importance in the New World. The male terminalia of both insects show morphological differences that are now described from scanning electron microscope (SEM) observations.

1. Third instars of the invasive blow fly Chrysomya rufifacies are facultative predators on larvae of the native blow fly Cochliomyia macellaria. 2. The effects of priority arrival time on the survivorship and fitness of C. rufifacies and C. macellaria were investigated in laboratory experiments. 3. Cochliomyia macellaria colonising a resource within 1-2 days after C. rufifacies resulted in a 20-70% reduction in survivorship, pupal weight and fecundity compared with those colonising a resource more than 2 days before or after C. rufifacies. Inversely, C. rufifacies exhibited a 50% increase in survivorship and fecundity when closely (∼2 days) associated temporally on the resource with C. macellaria and was negatively affected by disparate arrival. 4. These results demonstrate that arrival sequence significantly affects the fitness of both C. rufifacies and C. macellaria. Early colonisation may allow C. macellaria to persist in a community, while there are fitness benefits for C. rufifacies colonising after C. macellaria. 5. The 60% reduction in C. macellaria survivorship when in close temporal association with C. rufifacies may act as an agent of selection for C. macellaria to colonise a resource early and develop quickly to avoid predation on resources colonised by C. rufifacies. 6. Selection for such traits may explain how C. macellaria is able to persist despite intraguild predation by this invasive species. In contrast, the 50% increase in survivorship and fecundity exhibited by C. rufifacies when arriving after C. macellaria may select for C. rufifacies to delay colonisation. [ABSTRACT FROM AUTHOR]

Amplified Fragment Length Polymorphism (AFLP) analysis of entomological material provides a means of obtaining a reproducible DNA profile in a relatively short period of time. AFLP profiles were obtained using larval samples from Cochliomyia macellaria, Phormia regina and Sarcophaga bullata. Genomic DNA was isolated using the DNeasy Tissue Kit (Qiagen, Valencia, CA), double-digested by two restriction endonucleases (EcoRI and MseI) and ligated to oligonucleotide adapters. Two consecutive PCR reactions (preamplification and selective amplification) were performed using a modification of the AFLP protocol described by Gibco (Invitrogen, Rockville, MD). The DNA fragments were separated by capillary electrophoresis using the CEQ 8000 DNA Fragment Analyzer. Species specific profiles were developed for all three species. The results indicate that the AFLP technique is a viable and valuable technique for identification of entomological material. [ABSTRACT FROM AUTHOR]

Hydrocarbons were the major lipid class extracted by hexane from the vitelline membrane surface of dechorionated eggs of the house fly, Musca domestica, the New World screwworm, Cochliomyia hominivorax, the secondary screwworm, Cochliomyia macellaria, the green bottle fly, Phaenicia sericata, the sheep blow fly, Lucilia cuprina and the Mexican fruit fly, Anastrepha ludens. The length of time the embryos must be exposed to hexane with or without a small amount of alcohol in order to attain permeability was species-dependant. Long-chain n-alkanes comprised the major lipid class removed from vitelline membranes of all species except A. ludens where 2-methylalkanes were the major class. The range in size by the total number of carbon atoms in the hydrocarbons was: C23–C49 in C. hominivorax, C27–C33 in C. macellaria, C24–C35 in L. cuprina, C25–C36 in M. domestica, C25–C33 in P. sericata and C21–C51 in A. ludens. The major hydrocarbon component, expressed as percent of the total hydrocarbons, was n-nonacosane (C29) in C. hominivorax (40%), C. macellaria (43%), L. cuprina (38%), M. domestica (39%) and P. sericata (60%). However, in A. ludens, 2-methyloctacosane (32%) was the major hydrocarbon. Unsaturated hydrocarbons, monoenes (16%) and dienes (11%), were abundant only in A. ludens. Since prior studies indicated that the length of time the embryos must be exposed to hexane with or without a small amount of alcohol in order to attain permeability is species dependant, we suggest that the differences in hydrocarbon composition may contribute to this variation in lipid extractability. [Copyright &y& Elsevier]

Summary The primary screwworm fly Cochliomyia hominivorax (Coquerel) (Diptera: Calliphoridae) is one of the most important insect pests of livestock in neotropical regions, whereas Cochliomyia macellaria (Fabricius) (Diptera: Calliphoridae), the secondary screwworm, is of medical and sanitary importance because of its role in the dissemination of pathogens. These two species share morphological similarities and both may occur in the same myiasis, but in different developmental stages. In this work, the usefulness of PCR-RFLP (polymerase chain reaction – restriction fragment length polymorphism) of mitochondrial DNA (mtDNA) for the unambiguous identification of C. hominivorax and C. macellaria was investigated. Two specific regions of mtDNA were amplified: 870 bp from Cytochrome oxidase subunit I and 2100 bp from the A + T rich/12S region from C. hominivorax and C. macellaria specimens from different areas of Brazil. Reliable species-specific PCR-RFLP results were obtained for the CO I region and the A + T rich/12S region using the restriction enzymes Dra I and Ssp I. These results confirm the conservation of CO I diagnostic restriction sites previously reported and demonstrate the usefulness of the control region sequences as an efficient marker for PCR-RFLP identification of Brazilian screwworm flies. The occurrences of intraspecific polymorphic patterns are discussed based on frequencies and potential conflicts for species identification. PCR-RFLP provides a potentially useful method for identifying samples from the areas where these species are monitored. [ABSTRACT FROM AUTHOR]

Chrysomya rufifacies (Macquart) (Diptera:Calliphoridae) and Cochliomyia macellaria (Fabricius) (Diptera:Calliphoridae) are two Calliphorid carrion feeding species of significant importance in forensic investigations. Pupal weight was predicted to be an effective indicator of sex and species identification between the two related species when reared in a laboratory. In order to test the effectiveness in the field, wild maggots of both species were reared and the pupae of their offspring were weighed and sexed. There was no significant weight difference found between male and female pupae of both species. However when each species was compared to the other, it was observed that male and female pupae of Ch. rufifacies weighed significantly more than their C. macellaria counterparts. These results could simplify the identification of species at the pupal stage, thereby expediting research involving the two species. [ABSTRACT FROM AUTHOR]

As part of a survey on necrophagous Diptera species in a fragment of seasonally dry tropical forest in Brazil, six species of Calliphoridae are reported here for the first time in the caatinga, a biome exclusive to Brazil. Three species native to the Neotropical region (Cochliomyia macellaria, Chloroprocta idioidea, Lucilia eximia) and 3 exotic species (Chrysomya albiceps, C. putoria and C. megacephala) are reported to occur simultaneously associated with pig carcasses in the semiarid region of Brazil. The invasive potential of Chrysomya species is likely to produce deleterious effects on native blow fly populations in the near future. [ABSTRACT FROM AUTHOR]

Since its establishment in the Americas, the invasive species Chrysomya albiceps has been displacing native species such as Cochliomyia macellaria. Behavioural traits associated with this phenomenon are poorly understood, particularly in semiarid environments, as in the Caatinga , the largest seasonally dry tropical forest in the world, endemic to Brazil, where resource availability is critical. Under hot and dry conditions, differences in flight activity may influence competitive abilities. We investigated the preferential time of flight of C. albiceps and C. macellaria in a fragment of Caatinga , based on the capture of adults in baited traps. Four diurnal treatments were used: 05:30 h to 08:30 h (early morning), 8:30 h to 11:30 h (late morning), 11:30 h to 14:30 h (early afternoon) and 14:30 h to 17:30 h (late afternoon), plus collections from 17:30 h to 05:30 h of the following day (night time). The results revealed that C. macellaria was almost three times more abundant than C. albiceps and that both species were least captured in the early morning and increasingly so during the day until the latter treatment. Curiously, no insect was collected in nocturnal samples. Contradictorily to our initial hypothesis, flies were mostly captured in the hottest and driest periods of the day. The similarity in flight temporal activity between the two species suggests that they may arrive at (and colonize) a substrate at the same time, with important implications for carrion ecology and forensic entomology. Image 1 • Chrysomya albiceps and Cochliomyia macellaria have similar temporal flight patterns. • Both species are most active in the hottest periods of the day. • Neither species was observed flying during the nocturnal treatment. • Our results boost the use of the species in forensic cases in semiarid regions. [ABSTRACT FROM AUTHOR]