<p> Though it is well established that insects are attracted to decomposing vertebrates, little is known about the mechanism of attraction. Olfaction is thought to be the primary sense involved in resource location by necrophilous insects, and several studies have attempted to identify cadaveric-produced volatile organic compounds (VOCs) that contribute to insect attraction. This previous research has been completed almost exclusively in lab settings, with no field studies to verify these findings. </p><p> The goal of my thesis was to test necrophilous insect attraction to nine cadaveric VOCs (1-butanol, 1-pentanol, <i>p­</i>-xylene, <i>o</i>-xylene, ethanol, cyclohexanone, acetamide, dimethyl disulfide, and dimethyl trisulfide) in a field setting. Pitfall traps at six research locations were baited with the chemicals for one week. Specimens collected from the traps were identified and species assemblages were compared to those of a pig carcass. Replicates were conducted in fall 2018 and spring 2019. </p><p> Two chemicals were identified as important attractants for a variety of necrophilous insects: dimethyl disulfide and dimethyl trisulfide. These chemicals were especially attractive to <i>Phormia regina</i>, a blow fly (Diptera: Calliphoridae) found worldwide. VOC insect communities did not include all of the insects found on carcasses, possibly indicating the necessity of chemical blends for effective attraction. This study is only the second study to test necrophilous insect attraction in a field setting. </p>

Submitted by Jorge Silva (jorgelmsilva@ufrrj.br) on 2018-04-27T17:35:24Z No. of bitstreams: 1 2014 - Thiago Blanc Celino.pdf: 6972677 bytes, checksum: 143eeb47588b45b8bb4ab7a3bf4e4d31 (MD5) / Made available in DSpace on 2018-04-27T17:35:25Z (GMT). No. of bitstreams: 1 2014 - Thiago Blanc Celino.pdf: 6972677 bytes, checksum: 143eeb47588b45b8bb4ab7a3bf4e4d31 (MD5) Previous issue date: 2014-03-27 / CAPES / This work was performed in human cadavers and animal carcasses, with the aim to describe the injuries and assess the evolution of these artifacts during development of the decomposition process. The cadavers were examined at the scene and at the morgue. Two types of substrates were found: found accidentally and intentionally exposed to the activity of ants. Data collection for the bodies lasted a year, in Rio de Janeiro and Amazonas. Data collection for carcasses was held in July, followed by two years in an army barracks, in Rio de Janeiro. The specimens were collected with tweezers and transported to the laboratory immersed in 70% ethanol. We used three domestic pig - Sus scrofa, dead at the scene by shooting projectile firearm and exposed areas with nests inside a modified Shannon trap, a distance of 50 meters from each other. Four pitfalls were arranged around the traps. Photographs were made and only one or two specimens that caused artifacts were collected, relating them with injuries. The specimens were conducted for Myrmecology Laboratory of the Federal Rural University of Rio de Janeiro for identification. During the research , we analyzed eight cases of human cadavers, in which were collected : a) Myrmicinae subfamily , tribe Solenopsidini possibly genus Solenopsis spp b ) Camponotus sp.1 c ) Camponotus sp.2 d ) Camponotus rufipes ; e) Pheidole sp. 1 f ) Ectatomma sp.1 g ) Cephalotes atratus h) Crematogaster sp.1 i) small ants unidentified. However , only the first taxon was found associated with the corpses of the IML. Associated with animal carcasses were found : a) Solenopsis sp.1 b ) Pheidole sp.1 c ) Brachymyrmex sp.1 d ) Wasmannia sp.1 e) Ectatomma lugens . The latter being associated with animal carcass found accidentally. Among the collected species, Ectatomma sp.1 Brachymyrmex sp.1 and Wasmannia sp.1 causing artifacts were not observed. The lesions encountered can be described as serpentine punctuated by presenting color ranging from yellow to dark brown. They had removing skin surface such as scratches, in some cases, removal of the evolved to underlying tissues. In some cases, the detachment of the epidermis formed a clump of skin similar to those observed in cadavers in more advanced stage of decomposition. The jaws of the ants produce lesions in the superficial vessels causing bleeding postmortem. We also observed similar chemical injuries to injuries intra vitam produced by burning acid and / or smoking. Lesions caused by Solenopsis sp. was possible to trace the tracks of foraging evidenced by formic acid , as well as the accumulation of dirt, indicating the attempt of ants close these post-mortem lesions. It was found that ants can lead to skeletonization of small carcasses. The domestic pig carcasses showed artifacts similar to those found in bodies, at least until they reach the beginning of the initial stage of deterioration, when the activity of the flies hampered his observation. / Este trabalho foi realizado em cad?veres humanos e em carca?as animais, com o objetivo de descrever as les?es e avaliar a evolu??o desses artefatos durante o desenvolvimento do processo de decomposi??o. Os cad?veres humanos foram examinados na cena do crime e no necrot?rio. Dois tipos de carca?as foram avaliadas: encontradas acidentalmente e intencionalmente expostas ? atividade de formigas. A coleta de dados relativa aos corpos durou um ano, no Rio de Janeiro e no Amazonas e a relativa ?s carca?as foi realizada em julho, por dois anos seguidos, no Rio de Janeiro. Os esp?cimes foram coletados com pin?as e transportados ao laborat?rio fixados em etanol 70%. Foram utilizados tr?s porcos dom?sticos - Sus scrofa, mortos no local, atrav?s de disparo de proj?til de arma de fogo e expostos em ?reas com formigueiros dentro de uma armadilha tipo Shannon modificada, a dist?ncia de 50 metros uma das outras. Quatro armadilhas de solo foram dispostas entorno das armadilha Shannon. Fotografias foram confeccionadas e apenas um ou dois exemplares que causaram os artefatos foram coletados, relacionando-os com as les?es. Os exemplares foram conduzidos para o Laborat?rio de Mirmecologia da Universidade Federal Rural do Rio de Janeiro para identifica??o taxon?mica. Durante a pesquisa, foram analisados oito casos de cad?veres humanos, nos quais foram observados: a) Subfam?lia Myrmicinae, Tribo Solenopsidini, g?nero Solenopsis spp; b) Camponotus sp.1; c) Camponotus sp.2; d) Camponotus rufipes; e) Pheidole sp. 1; f) Ectatomma sp.1; g) Cephalotes atratus; h) Crematogaster sp.1; i) formigas pequenas n?o identificadas. Por?m, apenas o primeiro t?xon foi encontrado associado aos cad?veres do IML. Associados ?s carca?as animais foram encontrados: a) Solenopsis sp.1; b) Pheidole sp.1; c) Brachymyrmex sp.1; d) Wasmannia sp.1; e) Ectatomma lugens; sendo esta ?ltima associada ? carca?a animal encontrada acidentalmente. Dentre todas as esp?cies coletadas, Ectatomma sp.1, Brachymyrmex sp.1 e Wasmannia sp.1 n?o foram observadas causando artefatos. As les?es encontradas podem ser descritas como serpentiformes, pontuadas, apresentando colora??o que variava do amarelo at? o marrom escuro. Elas apresentavam remo??o de pele superficial como arranh?es que, em alguns casos, evolu?ram at? a remo??o dos tecidos subjacentes. Em alguns casos, o destacamento da epiderme formou um amontoado de pele similar ?queles observados em cad?veres em est?gio de decomposi??o mais avan?ados. As mand?bulas das formigas produziram les?es nos vasos superficiais causando sangramento p?s-morte. Tamb?m foram observadas les?es qu?micas similares a les?es intra vitam produzidas por queimadura de ?cido e/ou cigarro. Nas les?es provocadas por Solenopsis sp. foi poss?vel tra?ar as trilhas de forrageamento evidenciadas pelo ?cido f?rmico, bem como pelo ac?mulo de sujeira, indicando a tentativa das formigas fecharem estas les?es p?s-morte. Foi verificado que as formigas podem levar a esqueletiza??o de carca?as de pequeno porte. As carca?as de porco dom?stico apresentaram artefatos similares ?queles encontrados em corpos humanos, pelo menos at? alcan?arem o in?cio do est?gio de deteriora??o inicial, quando a atividade dos d?pteros dificultou sua observa??o.

Les larves de Diptères nécrophages se développant sur un cadavre font face à de fortes pressions de sélection. Nous démontrons comment cet environnement extrême aurait favorisé l’apparition de stratégies comportementales efficaces et originales, basées sur des mécanismes comme la régulation thermique mais également la socialité.Ce travail pose en premier lieu les bases du comportement de régulation thermique des larves de Diptères Calliphoridae. En effet, celles-ci sont confrontées à un environnement thermique très hétérogène, dans lequel elles vont sélectionner la zone la plus appropriée à leur activité métabolique. Bien que différentes espèces exploitent la même ressource au même moment, nous avons observé que les larves de Lucilia sericata, Calliphora vomitoria et Calliphora vicina ont chacune une température préférentielle de développement. De plus, nous démontrons que ces larves sont en recherche constante de leur température préférentielle (thermorégulation), et qu’elles adaptent leur alimentation à la température du milieu. Ce premier volet d’expérimentations illustre ainsi le rôle prépondérant de la température dans le comportement des larves. En second lieu, ce travail s'intéresse à la dimension sociale des larves nécrophages, et plus particulièrement au comportement d'agrégation. Nous avons démontré chez Lucilia sericata un fort effet attractif et rétentif des congénères, rendant manifeste une prévalence de la socialité sur la régulation thermique. Les résultats sont cependant drastiquement différents dans des conditions hétérospécifiques, où la formation du groupe varie selon les températures préférentielles et les cinétiques d’agrégation de chaque espèce. Ainsi, la température sélectionnée par un groupe hétérospécifique émerge d'un compromis entre les comportements de thermorégulation et d'agrégation. Enfin, ce travail analyse l’effet de ces stratégies comportementales sur le développement des individus.Nous montrons que le comportement de thermorégulation et l’action des congénères affectent la température sélectionnée par les larves, et donc, leur développement. De tels résultats démontrent l’existence de véritables stratégies comportementales individuelles et collectives de développement, reposant sur l’optimisation de paramètres multiples permettant aux larves de se développer au mieux dans cet écosystème extrême qu’est le cadavre en décomposition. / On a cadaver, necrophagous dipteran larvae suffer from strong selection pressures during their development. The premise of this thesis is that such an extreme, competitive and constraining environment would have favored the emergence of efficient developmental strategies, based on mechanisms such as thermal regulation but also sociality. This PhD work is divided into three parts. The first part focuses on the thermal behavior of Calliphorids larvae, which are confronted with a heterogeneous thermic environment on the corps, in which they select the most appropriate area for their metabolic activity. Firstly, this part shows that larvae have a preferential developmental temperature, which is different according to the species (Lucilia sericata, Calliphora vomitoria and Calliphora vicina), although they exploit the same resource at the same time. Secondly, this part demonstrates that the larvae are always in search of this preferential temperature and thirdly, that they adapt both their displacement and their food intake according to the temperature of the nourishing substrate. This first part of experiments demonstrates that the temperature parameters have a strong effect on larval behavior. The second part of this work focuses on the social dimension of larval behavior by analyzing the influence of congeners, mainly through their active aggregation behavior. We show for Lucilia sericata a strong attractive and retentive effect of the group, making obvious that sociality prevails over thermal regulation. However, these results are radically different under heterospecific conditions where the group formation strongly depends on preferential temperatures as well as aggregation kinetics of each species. Finally, the third part of this work analyzes the effects of temperature and congeners on the development of individuals and shows that both the behavior of thermoregulation and the action of congeners impact the temperature selected by larvae, and therefore, their development. These results indicate the existence of individual and collective behavioral development strategies based on the optimization of multiple parameters that allow larvae to develop ideally in this extreme ecosystem of a decaying corpse.

This investigation explored the environmental and physiological factors affecting adult blow fly (Diptera: Calliphoridae) arrival and attendance at pig (Sus scrofa domesticus L.) carcasses in Brazos Co, TX in the summer and winter, and validated a new technique for estimating the pre-colonization interval. It also examined how the offspring of said blow flies compensate for adverse developmental conditions such as starvation or the presence of older competitors by determining the function of minimum viable weight, critical weight, and the terminal growth period in Cochliomyia macellaria (F.) (Diptera: Calliphoridae). Adult blow fly carcass attendance is poorly explained by temperature, wind speed, ambient light intensity, or body size for either winter or summer-active species. Time of day explained approximately 10% in carcass size variation for all four of the most common species. For summer flies, the degree of ovarian development changed significantly from 96%/98% fully developed on day 1 postmortem to 7%/2% fully developed on day 2 postmortem for C. macellaria and Chrysomya rufifacies (Macquart) iv respectively. Using the binomial distribution, the minimum postmortem interval was correctly estimated for 4/6 validation tests. Minimum viable weight for C. macellaria was found to be ~ 0.02 g, and was stable under conditions of starvation and simulated competition. Under starvation conditions, time to pupariation was not altered, whereas under simulated competition, growth rate was increased and terminal growth period shortened. Starved flies under simulated competition entered the pupal state ~12 h faster than starved flies without competition, but required ~12 longer to complete development. These effects should be considered when estimating post-colonization intervals.

Chrysomya rufifacies and Cochliomyia macellaria are two medically and forensically important necrophagous flies that dominate ephemeral resources in the southern US. Since its introduction in 1981, Ch. rufifacies has become established throughout the New World due to its larvae being facultative predators. Through this research I examined the interaction between the native, primary colonizer C. macellaria and the invasive, secondary colonizer Ch. rufifacies and elucidated the olfactory mechanisms used to locate, colonize, and exploit ephemeral resources. This work used competition experiments, olfactometer experiments, and high-throughput sequencing to investigate the effects of priority colonization of ephemeral resources on both species, the olfactory mechanisms employed by gravid females to locate a resource, and the effects of egg-associated volatiles on those females. Results from competition experiments indicated that priority sequence significantly affected the fitness of both C. macellaria and Ch. rufifacies. Regulation of colonization time is not chiefly governed by resource age, as previously thought, but is affected by colonization of the resource by conspecific and heterospecific individuals. Colonizing adults may use cues from early colonizers to assess resource quality. These cues may be derived from the physiology of the eggs, the 31-39 species of bacteria I determined are present on the egg chorion, or some combination of both. Design of these experiments facilitated the development of techniques to surface-sterilize Calliphoridae eggs, analyze behavior of adults in a dual choice olfactometer, and associate adult response to conspecific and heterospecific eggs with environmental cues that ultimately affect larval fitness.

Carrion decomposition is an essential ecosystem function as it is an important component of nutrient cycling. Carrion decomposition has primarily been attributed to insect consumption, with little attention given to microbial communities or their potential interactions with insects. The first objective was to use passive insect-trapping methods to assess primary colonizer communities on swine carcasses between two treatments: 1) carrion with access to insects and 2) carrion excluded from insect access for five days using exclusion cages. Despite similarities between succession patterns within each treatment, carcasses initially exposed to insects had significantly fewer insect taxa. Therefore, collections of adult insect communities associated with carrion are promising as an indication of whether or not there has been a delay in insect colonization of a resource. There has yet to be a study documenting bacterial communities during carrion decomposition. The second objective was to describe bacterial community succession and composition during decomposition in the presence and absence of naturally occurring insects. Total genomic DNA was used to identify bacterial community composition via a modified bacterial tagged encoded FLX amplicon pyrosequencing. I obtained 378,904 sequences and documented distinct bacterial community successional trajectories associated with insect access and exclusion carcasses. By the fifth day of decomposition, Proteus was the dominant (72%) bacterial genus on exclusion carcasses while Psychrobacillus (58%) and Ignatzschineria (18%) were dominant bacterial genera on insect carcasses. These data are the first to document bacterial community composition and succession on carrion. My final objective was to assess microbial community function in response to carrion insect colonization using metabolic profiling. I characterized microbial community metabolic function in the presence and absence of the primary necrophagous insects. I documented significant microbial community metabolic profile changes during active decomposition of carcasses. Mean carcass microbial community metabolic function with insect access continuously decreased over decomposition during both field seasons. Thus demonstrating microbial metabolic activity may have discriminatory power to differentiate early and late stages of decomposition. Overall, my data contributes to an understudied area of microbial research important to organic matter decomposition, forensic entomology, and microbial-insect ecological interactions.

It is commonly thought that blow flies are nocturnally inactive. Blowflies are often important in helping to estimate post mortem intervals (PMI) for corpses found at death scenes. If blow flies oviposit during nocturnal hours, there could possibly be up to 12-hour discrepancies for estimates of PMI. Two blow fly species, Phaenicia eximia (Wiedemann) and Cochliomyia macellaria (F.), oviposited nocturnally on ground beef baits in 2003, during the onset of low-atmospheric pressure (an air mass with lower atmospheric pressure than that of the air surrounding it) at rural study sites near Snook (Burleson County), Texas, under artificial lighting of at least 1500 footcandles when temperatures were at 26?C or higher. Trials conducted under similar conditions during the same year without a low-pressure system moving into the area resulted in no nocturnal blow fly oviposition. Nocturnal blow fly oviposition went undetected once low-atmospheric pressure systems settled into the study area, irrespective of temperature and lighting conditions. Thus, this study illustrates that there is a connection between the onset of low-atmospheric pressure and nocturnal blow fly oviposition on baits under artificial lighting of 1500 footcandles or more when temperatures are 26 ?C or above. After concluding 2003 experiments, statistical analyses supplied evidence that woodland habitat was more favorable for blow fly oviposition than prairieland habitat throughout the 2003 study, irrespective of species or time of year. Furthermore, statistical analyses conducted on nocturnal and diurnal temperature ranges furnished evidence to support the hypothesis that 2003 nocturnal temperatures had more of an effect on daily ovipositing than diurnal temperatures for P. eximia and Cynomyopsis cadaverina (Robineau-Desvoidy).

[Truncated abstract] A common application of forensic entomology is the estimation of post-mortem interval (PMI). This is most frequently estimated from the age of calliphorid specimens collected from a corpse, and in many cases it is the immature stages that are encountered. A critical step in the estimation of PMI is the accurate identification of insects to species level, with misidentification potentially resulting in the application of unsuitable developmental data and therefore inaccuracy in the resulting estimate. Identification has long been attempted on a morphological basis, but complicated by the lack of larval keys to the Calliphoridae, limited diagnostic features in immature stages and the poor preservation of specimens. Standard practice in forensic entomology is the rearing of immatures collected from the corpse through to the more distinctive adult stages, however this process is time-consuming and may be hindered where specimens die during rearing. Furthermore, many cases are presented for forensic entomologist as an afterthought and specimens are already preserved. Consequently, a new approach to the identification of calliphorids is sought which will overcome the problems of the morphological and rearing methods. ... The culmination of this study is the consideration of applications of molecular data to forensic entomology. A sequence-specific priming (SSP) technique is presented for the identification of the forensically significant calliphorids of Australia and New Zealand, along with a new method for the extraction and storage of calliphorid DNA samples using Whatman FTA cards. These techniques will potentially improve the efficiency and accuracy of identification in the estimation of PMI using calliphorids. The use of calliphorid DNA is not limited to PMI estimation, but may also be applied to museum studies. DNA was extracted from pupal casings from 300 year old mummified corpses, however difficulty was encountered in amplifying the DNA reproducibly. This illustrates however, the wide-ranging implications of the calliphorid sequence data gathered in this study. This thesis makes a significant contribution to the consideration of the status of some global calliphorid species. The new technique presented for identification of Australian and New Zealand species is the culmination of an important body of data that will ultimately contribute to the strong foundation of forensic entomology and our future accuracy, efficiency and utility as a routine investigative tool.

Thesis (M.Sc.)--University of Wollongong, 2006. / Typescript. Includes bibliographical references: leaf 178-186.

Made available in DSpace on 2015-04-17T14:55:29Z (GMT). No. of bitstreams: 1 arquivototal.pdf: 2522413 bytes, checksum: 2dcde9206193aa66227f1638607e57cd (MD5) Previous issue date: 2013-07-30 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES / Beetles associated with decomposing carcasses in restinga environment, are being studied in this research, contributing information to forensic entomology, with respect to the estimated time of death of a body and translocation corpse. Four carcasses of pigs were used, two for each season in 2012. The carcasses were killed with a shot in the cranial region and placed in cages to prevent the action of scavengers. To collect beetles were used Shannon traps, pitfalls and collecting in the tray. We sampled 3,763 beetles belonging to 19 families and 96 species. The most abundant family was Histerid (n=1,406), followed by Staphylinidae (n=987) and Scarabaeidae (n=718). The family with the highest richness was Staphylinidae (S=23). The most species sampled were Euspilotus sp. 1 (n=930) Xerosaprinus diptychus (n=229) Euspilotus sp. 4 (n=155), Hypocaccus sp. (n=48) (Histeridae), Atheta sp. 1 (n=457), Hongophila sp. (n=269) Lissohypnus sp. (n=81), Philonthus sp. 1 (n=78) (Staphylinidae), Aidophus impressus (n=372), Dichotomius sp. gr geminatus (n=215), Parataenius simulator (n=64), Ateuchus sp. (n=46) (Scarabaeidae), Dermestes maculatus (n=143) (Dermestidae), Necrobia rufipes (n=104) (Cleridae) and Omorgus suberosus (n=78) (Trogidae). Due the difference in abundance and richness was observed seasonal behavior of beetles, since 80% were sampled in the rainy season and the richness ranged from 59 in this season to 26 in drought season. The succession of beetles varied from one station to another, probably due to the seasonal behvior. The nighttime show higher abundance of beetles (54%). The families with abundance above 70% during the night were Trogidae (78%), Tenebrionidae (74%) and Scarabaeidae (72%). None family had such value for daytime. The species referred to as potential forensic to restinga were D. maculates and N. rufipes by reproducing in the carcasses, and also Hypocaccus sp. and Bledius fernandezi by presenting a strict record of dunes and beach, similar environments studied here, suggesting that these species serve as indicators of the area. / Os besouros associados a carcaças em decomposição, em ambiente de restinga, estão sendo estudados no presente estudo, visando contribuir com informações para a Entomologia Forense, no que diz respeito à estimativa do tempo de morte de um corpo e translocação de cadáver. Quatro carcaças de suínos foram utilizadas como isca para atração dos insetos, duas para cada estação climática em 2012. As carcaças foram mortas com um tiro na região craniana e colocadas em gaiolas para impedir a ação de animais necrófagos de grande porte. Para coleta dos besouros foram utilizadas armadilhas Shannon, pitfalls e coletas em bandeja. Foram coletados 3.763 besouros pertencentes a 19 famílias e 96 espécies. A família mais abundante foi Histeridae (n=1.406), seguida por Staphylinidae (n=987) e Scarabaeidae (n=718). A família que apresentou maior riqueza foi Staphylinidae (S=23). As espécies mais coletadas foram: Euspilotus sp. 1 (n=930), Xerosaprinus diptychus (n=229), Euspilotus sp. 4 (n=155), Hypocaccus sp. (n=48) (Histeridae), Atheta sp. 1 (n=457), Homalotina sp. (n=269), Neohypnus sp. (n=81), Philonthus hepaticus (n=78) (Staphylinidae), Aidophus impressus (n=372), Dichotomius sp. gr. geminatus (n=215), Parataenius simulator (n=64), Ateuchus sp. (n=46) (Scarabaeidae), Dermestes maculatus (n=143) (Dermestidae), Necrobia rufipes (n=104) (Cleridae) e Omorgus suberosus (n=78) (Trogidae). Devido à diferença de abundância e riqueza foi observado comportamento sazonal dos besouros, visto que 80% foram coletados na estação chuvosa e a riqueza variou de 59 nesta estação para 26 na estiagem. A sucessão dos besouros variou de uma estação para outra, provavelmente devido o comportamento sazonal. A maior abundância dos besouros foi observada no período noturno (54%), sendo as famílias que apresentaram abundância acima de 70% no período noturno foram Trogidae (78%), Tenebrionidae (74%) e Scarabaeidae (72%). Nenhuma família apresentou tal valor para o período diurno. As espécies indicadas como potencial forense para a restinga foram Dermestes maculatus e Necrobia rufipes por se reproduzirem nas carcaças, e também Hypocaccus sp. e Bledius fernandezi por apresentarem registro estrito a ambientes de dunas e praia, semelhantes ao aqui estudado, sugerindo-se que essas espécies sirvam como indicadores de área.