The predatory behavior of Hydrotaea albuquerquei (Lopes) larvae on the larvae of Musca domestica Linnaeus under laboratory conditions

ABSTRACT Larvae of Hydrotaea species are facultative predators of larvae of other fly species on poultry farms, chicken feces, pig, and decaying carcasses. The Neotropical species H. albuquerquei occurs together with M. domestica in these environments and might be useful in the biological control of the latter. To verify the predatory capacity of H. albuquerquei larvae on the larvae of M. domestica, we varied the size of the larvae and the densities of the predators and prey under controlled laboratory conditions. Adults were collected from a poultry farm for the experiment, and the larvae they produced were reared in the laboratory. The second and third instar larvae of H. albuquerquei, when at higher densities, suppressed populations of house fly larvae when the latter were smaller than the former. This means that the functional response increases gradually with an increase in prey population density and predator size. In these conditions, one H. albuquerquei larva consumes up to 29 M. domestica larvae at high prey densities and could reduce 100% of the house fly population under a 50% prey density. This study confirmed a pattern previously observed in other predatory larvae and our results have implications for the biological control and integrated pest management programs of M. domestica in poultry and swine farms.

Houseflies speaking for the conservation of natural areas: a broad sampling of Muscidae (Diptera) on coastal plains of the Pampa biome, Southern Brazil

ABSTRACT The Brazilian Coastal Plain of the Pampa Biome (CPPB), has suffered fragmentation caused by resource extraction and cattle raising. In turn, conservation proposals are needed to prevent the anthropisation of Pampa natural areas. The first step towards conservation proposals by using insects is fauna inventories, providing data support for legislators. Thus, we undertook a regional and broad-scale sampling survey to investigate the diversity of Muscidae flies in protected and non-protected areas of CPPB. In addition, we carried out an ecological guild diversity analysis as a metric approach of bioindication. The Muscidae sampling resulted in 6314 specimens, 98 species taxa in 31 genera. Based on diversity estimators, our sampling represents 70-86% of all muscids of CPPB. The highest diversity occurs in Pelotas streams (non-protected) and Taim Ecological Station (a huge protected area). Despite the fact these areas are more diversified and present more predatory muscid species than others, invasive species associated with livestock were observed at a higher level, providing evidence of the impact of livestock proximity to protected areas. Based on biological characters of Muscidae species and ecological guild analysis, we were able to identify: (i) high diversity of carnivorous species associated with forested and more preserved areas and (ii) a high level of a few saprophagous species as indicator of anthropisation process. In general, our results represent a significant step towards understanding Muscidae in Southern Brazil, and we demonstrate how the population ecology of muscid flies supports data to conservation proposals.

Domestic infestation by Sclerodermus sp. with associated skin manifestation

Abstract: Sclerodermus sp. is an aculeate insect (Hymenoptera: Bethylidae), measuring 2-4 mm in length. It is a parasitoid and needs termites as hosts to complete its life cycle. It is found in a wide variety of woods and may accidentally sting humans who come near affected wooden objects. A 50-year-old woman presented two episodes of intense pruritic lesions. Clinical diagnosis of insect bite was doubtful since there were no pets at home, lesions had not started during summer and the patient denied rural activities. During a night episode of itching, the patient examined her bed and found 8 insects likely to be responsible for the bites. Scanning electron microscopy revealed typical features of a female of the genus (wingless and with multiple stingers at the lower end of the abdomen).

Necrophagous diptera associated with wild animal carcasses in southern Brazil

Necrophagous Diptera associated with wild animal carcasses in southern Brazil. The aim of this study was to acquire a better knowledge concerning the diversity of necrophagous Diptera that develop on wild animal carcasses. For this purpose, the decomposition of six wild animal carcasses was observed in order to collect and identify the main species of necrophagous flies associated with the decomposition process. The carcasses were found on highways near the cities of Pelotas and Capão do Leão in the initial stage of decomposition, with no significant injuries or prior larval activity. Four wild animal models were represented in this study: two specimens of Didelphis albiventris Lund, 1840; two Tupinambis merianae Linnaeus, 1758; one Nothura maculosa Temminck, 1815; and one Cerdocyon thous Linnaeus, 1766. A total of 16,242 flies from 14 species were reared in the laboratory, where Muscidae presented the greatest diversity of necrophagous species. Overall, (i) carcasses with larger biomass developed a higher abundance of flies and (ii) the necrophagous community was dominated by Calliphoridae, two patterns that were predicted from published literature; and (iii) the highest diversity was observed on the smaller carcasses exposed to the lowest temperatures, a pattern that may have been caused by the absence of the generalist predator Chrysomya albiceps (Wiedemann, 1819). (iv) An UPGMA analysis revealed a similar pattern of clusters of fly communities, where the same species were structuring the groupings.

Interaction between Musca domestica L. and its predator Muscina stabulans (Fallén) (Diptera, Muscidae): effects of prey density and food source abundance

Interaction between Musca domestica L. and its predator Muscina stabulans (Fallén) (Diptera, Muscidae): Effects of prey density and food source abundance. The objective of this work was to evaluate the influence of prey density and food source abundance on the predatory behavior of Muscina stabulans over M. domestica. Three predator/prey proportions were evaluated (1:1, 1:3 and 1:6), using 100 third instar predator larvae against second instar prey larvae. Each proportion was maintained using three different levels of food substrate (25, 50 and 100 g). The experiments were carried out in triplicate in BOD incubators (25ºC, UR 70% ± 10% and 12 h photoperiod). The mortality of the M. domestica larvae was 100% under all conditions, except in the 1:6 predator/prey proportion, at the 50g and 100g food substrate levels, where it was 99.99% and 99.22%, respectively. There was a significant increase in the development period of M. stabulans in relation to the increase in prey density and decrease in quantity of food substrate. An increase in the proportion of individuals and a reduction in the amount of resource slowed down larval development. Muscina stabulans pupal weight was proportional to the increase in prey density and the amount of food substrate. The proportion or the density influenced the survival of M. stabulans, with no difference in relation to the amount of food source and consequently in the interaction of the factors. There was no difference between the 1:1 and 1:3 predator-prey densities, with both differing from the 1:6 density.

Phenology of Spalangia endius Walker (Hymenoptera, Pteromalidae) in pupae of Musca domestica Linnaeus (Diptera, Muscidae) under laboratory conditions / Fenologia de Spalangia endius Walker (Hymenoptera, Pteromalidae) em pupas de Musca domestica Linnaeus (Diptera, Muscidae) em condições de laboratório

This work describes the phenology of Spalangia endius Walker in pupae of Musca domestica Linnaeus under laboratory conditions. In order to understand the developmental cycle of Spalangia endius under laboratory conditions, 360 Musca domestica pupae aged from 24 to 48 hours were exposed to 15 S. endius pairs for a period of 24 hours at 26 ± 2ºC. These pupae were kept in a BOD incubator at the same temperature, with a relative humidity of <70%, and 12 hours photophase. Fifteen hymenopteran specimens were dissected daily to evaluate their stage and development time. The phenology concluded that S. endius had a development cycle of 19 days with an incubation period of 24 hours. The development of the larvae of S. endius occurred in the subsequent eight days, during which a series of morphological alterations were observed. The pre-pupal stage occurred on the tenth day, where the movement ceased and elimination of the meconium started. The pupal stage occurred from the 11th to the 19th day, with emergence of males first, followed by female emergence approximately 24 hours later. These results allowed the evaluation of aspects of the detailed bionomics of the development of S. endius in order to record and program production of this parasitoid, thus optimizing its utilization as a biological control agent.

Objetivando conhecer o ciclo de desenvolvimento de Spalangia endius sob condições de laboratório, 360 pupas de Musca domestica com idade de 24 a 48 horas foram expostas a 15 casais de S. endius por um período de 48 horas a 26 ± 2ºC. Estas pupas foram mantidas em BOD. Com mesma temperatura, umidade relativa <70% e com fotofase de 12 horas, onde diariamente dissecava-se 15 espécimes para avaliar o estágio e tempo de desenvolvimento do himenóptero. A fenologia permite concluir que S. endius apresenta um ciclo de desenvolvimento de 19 dias, cujo período de incubação foi de 24 horas, o desenvolvimento de larvas de S. endius ocorreu nos oito dias subsequentes nos quais uma série de alterações morfológicas foi observada. O estágio de pré-pupa deu-se no décimo dia onde cessa a movimentação e inicia a eliminação de mecônio. O estágio pupal ocorreu do décimo primeiro dia ao décimo nono, momento da emergência dos primeiros machos, já as fêmeas iniciaram a emergência aproximadamente 24 horas após. Estes resultados permitem avaliar aspectos da bionomia pormenorizada do desenvolvimento de S. endius para armazenar e programar a produção deste parasitóide, otimizando sua utilização como agente de controle biológico.

The effect of environment on development and survival of pupae of the necrophagous fly Ophyra albuquerquei Lopes (Diptera, Muscidae)

The effect of environment on development and survival of pupae of the necrophagous fly Ophyra albuquerquei Lopes (Diptera, Muscidae). Species of Ophyra Robineau-Desvoidy, 1830 are found in decomposing bodies, usually in fresh, bloated and decay stages. Ophyra albuquerquei Lopes, for example, can be found in animal carcasses. The influence of environmental factors has not been evaluated in puparia of O. albuquerquei. Thus, the focus of this work was motivated by the need for models to predict the development of a necrophagous insect as a function of abiotic factors. Colonies of O. albuquerquei were maintained in the laboratory to obtain pupae. On the tenth day of each month 200 pupae, divided equally into 10 glass jars, were exposed to the environment and checked daily for adult emergence of each sample. We concluded that the high survival rate observed suggested that the diets used for rearing the larvae and maintaining the adults were appropriate. Also, the data adjusted to robust generalized linear models and there were no interruptions of O. albuquerquei pupae development within the limits of temperatures studied in southern Rio Grande do Sul, given the high survival presented.

Efeito de fatores ambientais sobre o desenvolvimento e sobrevivência de pupas de Ophyra albuquerquei Lopes (Diptera, Muscidae). Espécies de Ophyra Robineau-Desvoidy, 1830 são encontradas em corpos em decomposição, usualmente nas fases fresca, inchamento e murcha. Entre estas espécies, Ophyra albuquerquei Lopes, 1985 pode ser encontrada em carcaças de ratos e coelhos. A influência de fatores ambientais sobre pupas de O. albuquerquei não tinha sido avaliada até o momento. Desta maneira, o foco deste trabalho foi motivado pela necessidade por modelos de previsão do desenvolvimento de insetos necrófagos em função de fatores abióticos. Colônias de O. albuquerquei foram mantidas em laboratório para a obtenção de pupas. Até o décimo dia de cada mês, 200 pupas distribuídas em 10 frascos de vidro foram expostas ao meio e foi verificada diariamente a emergência dos adultos de cada amostra. Os dados se ajustaram a modelos lineares generalizados robustos. Além disto, foi concluído que não existem limiares mínimos e máximos de temperatura para o desenvolvimento de pupas de O. albuquerquei no sul do Rio Grande do Sul, devido à alta sobrevivência apresentada.

Assembly rules in Muscid Fly assemblages in the grasslands Biome of Southern Brazil

The distribution of muscid species (Diptera) in grasslands fragments of southern Brazil was assessed using null models according to three assembly rules: (a) negatively-associated distributions; (b) guild proportionality; and (c) constant body-size ratios. We built presence/absence matrices and calculated the C-score index to test negatively-associated distributions and guild proportionality based on the following algorithms: total number of fixed lines (F L), total number of fi xed columns (F C), and the effect of the average size of the populations along lines (W) for 5000 randomizations. We used null models to generate random communities that were not structured by competition and evaluated the patterns generated using three models: general, trophic guilds, and taxonomic guilds. All three assembly rules were tested in each model. The null hypothesis was corroborated in all F L X F C co-occurrence analyses. In addition, 11 analyses of the models using the W algorithm showed the same pattern observed previously. Three analyses using the W algorithm indicated that species co-occurred more frequently than expected by chance. According to analyses of co-occurrence and guild proportionality, the coexistence of muscid species is not regulated by constant body size ratios. In fl ies of the grasslands, no rule was identified. Yet, a consensus did emerge from our analyses: species co-occur more frequently than expected by chance, indicating that aggregation is a recurring phenomenon among flies with saprophagous adults and predatory larvae. Therefore, competition does not seem to play an important role in the determination of muscid assemblages in the grasslands in Southern Brazil.

Reproduction and survival of Muscina stabulans under laboratory conditions / Reprodução e sobrevivência de Muscina stabulans em condições de laboratório

This is the first published report concerning reproduction and survival using life table analyses of fertility and survival for Muscina stabulans maintained under laboratory conditions with artificial diets. The intrinsic rate of growth, reproduction rate and average generational time were obtained, suggesting a rapid population growth under these rearing conditions. These findings permitted the creation of time models of survival and oviposition, as well as a quantitative estimate of the adaptation capacity of this species.

Com o objetivo de apresentar um primeiro delineamento para a reprodução e sobrevivência da Muscina stabulans em condições de laboratório, foram desenvolvidas tabelas de vida em dieta artificial. A taxa intrínseca de crescimento natural, a taxa reprodutiva líquida e o tempo médio de uma geração foram estimados, além da análise do tempo de oviposição e da sobrevivência dos adultos dessa espécie. Os dados sugerem uma alta taxa de crescimento da população nas condições de criação. Esses resultados permitem a criação de modelos de sobrevivência e oviposição, bem como estimativas quantitativas da adaptabilidade dessa espécie.

Rate of development of forensically-important Dipterain southern Brazil / Taxa de desenvolvimento de Diptera de importância forense no sul do Brasil

Dipteran larvae were collected from rabbit (Oryctolagus cunniculus L.) carcasses during the four seasons in 2005 in the southernmost state of Rio Grande do Sul, Brazil. The larvae were fed ground beef at ambient temperatures following collection from carcasses. The development of each species under these conditions was estimated. The most abundant species in the carcasses were Lucilia eximia (Wiedemann) and Chrysomya albiceps (Wiedemann) (Calliphoridae), and they were found in all seasons. The data were fitted to a linear model that describes the relationship between temperature and linear developmental rating. These two species are primary forensic indicators in southern Brazil. Other species such as Hemilucilia semidiaphana (Rondani) (Calliphoridae), Synthesiomyia nudiseta (Wulp), Muscina stabulans (Fallen) (Muscidae), and Fannia pusio (Wiedemann) (Fanniidae) were forensically less important because they only occurred in high frequency in certain seasons and during the first days of carcass decomposition.

Larvas de dipterous foram coletadas em carcaças de coelho-doméstico (Oryctolagus cunniculus L.) ao longo das quatro estações de 2005 no extremo-sul do Rio Grande do Sul, Brasil. As larvas foram alimentadas com carne bovina moída e acondicionadas em temperatura ambiente. O desenvolvimento de cada espécie foi acompanhado nestas condições. As espécies mais abundantes na carcaça foram Lucilia eximia (Wiedemann) e Chrysomya albiceps (Wiedemann) (Calliphoridae) em todas as estações. Os dados foram ajustados a um modelo linear da relação entre a taxa de desenvolvimento destas espécies e a temperatura média diária do ambiente. Estas duas espécies são as principais indicadoras forense no sul do Brasil. Outras espécies como Hemilucilia semidiaphana (Rondani) (Calliphoridae), Synthesiomyia nudiseta (Wulp), Muscina stabulans (Fallen) (Muscidae) e Fannia pusio (Wiedemann) (Fanniidae) foram menos importantes porque ocorreram em alta abundância em determinadas estações do ano no decorrer dos primeiros dias de decomposição.

Insects of forensic importance from Rio Grande do Sul state in southern Brazil / Insetos de importância forense do Rio Grande do Sul, sul do Brasil

The experiment was conducted throughout the year 2005, at the Universidade Federal de Pelotas campus. The objectives of the study were to analyze the decomposition of rabbit (Oryctolagus cunniculus L.) with mean weight 2.67 Kg carcass and describe the interaction of insects acting on it, as well as the insect's potential use in legal medicine. We collected 5.239 insect specimens; 1.827 of them were obtained from larvae collected from carcasses and reared. The specimens were identified and 20 species were of forensic importance. The species Lucilia eximia (Wiedemann, 1819) and Chrysomya albiceps (Wiedemann, 1819) (Diptera, Calliphoridae) were better indicators of post-mortem interval (PMI) because they occurred in all seasons and were the first to reach the carcass. Hemilucilia semidiaphana (Rondani, 1850), H. segmentaria (Fabricius, 1805) (Diptera, Calliphoridae), Muscina stabulans (Fallén, 1817) and Synthesiomyia nudiseta (Wulp, 1883) (Diptera, Muscidae) can disclose death time because they occur only in certain months of the year. Oxyletrum discicolle (Brullé, 1840) (Coleoptera, Silphidae) and Dermestes maculates De Geer, 1774 (Coleoptera, Desmestidae) were found in advanced stages of decomposition.

Durante todas as estações do ano de 2005 foi conduzido um experimento em uma área do campus da Universidade Federal de Pelotas. O objetivo do estudo foi analisar a decomposição de carcaças de coelho (Oryctolagus cunniculus L.) pesando 2,67 Kg em média e descrever como os insetos atuam na decomposição e seu possível uso na medicina-legal. Foram coletados 5.239 espécimes; 1.827 foram obtidos a partir da criação de imaturos coletados na carcaça. Foram identificadas 20 espécies com importância forense. As espécies mais propícias para serem usadas com indicadoras de intervalo post-mortem (IPM) são Lucilia eximia (Wiedemann, 1819) e Chrysomya albiceps (Wiedemann, 1819) (Diptera, Calliphoridae) por terem sido encontradas em todas as estações de coleta e por serem uma das primeiras espécies a chegar à carcaça. Hemilucilia semidiaphana (Rondani, 1850), H. segmentaria (Fabricius, 1805) (Diptera, Calliphoridae), Muscina stabulans (Fallén, 1817) e Synthesiomyia nudiseta (Wulp, 1883) (Diptera, Muscidae) são espécies que podem indicar época da morte, pois ocorrem em meses específicos do ano. Oxyletrum discicolle (Brullé, 1840) (Coleoptera, Silphidae) e Dermestes maculatus De Geer, 1774 (Coleoptera, Desmestidae) são encontrados em estágios avançados de decomposição.

Chave pictórica para os gêneros de Tabanidae (Insecta: Diptera) do bioma Campos Sulinos, Rio Grande do Sul, Brasil / Illustrated key for Tabanidae (Insecta: Diptera) genera of Campos Sulinos biome, Rio Grande do Sul, Brazil

Foram realizadas coletas de tabanídeos ao longo de quatro anos (2002-2006) no extremo sul do Rio Grande do Sul, Brasil. Apresenta-se uma lista com 30 espécies, além de chave pictórica e diagnoses para identificação dos 15 gêneros encontrados na região. Nove espécies são registradas pela primeira vez no estado do Rio Grande do Sul.

Tabanids were collected and preserved along four years (2002-2006) in southern Rio Grande do Sul, Brazil. A list of 30 species is presented along with an illustrated key and diagnoses for identification of the 15 genera found in the area. Nine species are registered for the first time in the state of Rio Grande do Sul.

Estimativa de entropia de Muscina stabulans (Fallén) (Diptera, Muscidae) em condições artificiais / Entropy estimation in Muscina stabulans (Fallén) (Diptera, Muscidae) under laboratory conditions

Estimativa de entropia de Muscina stabulans (Fallén) (Diptera, Muscidae) em condições artificiais. O conceito de entropia (H) foi adaptado da mecânica estatística para a demografia para quantificar o impacto da mortalidade na expectativa de vida e demonstrar quantitativamente a tendência da mortalidade em populações experimentais. Isto foi verificado para 160 casais de Muscina stabulans (Fallén, 1817) mantidos em câmara climatizada a 24,8°C ± 0,6°C, umidade relativa do ar entre 70 e 80 por cento e fotofase de 12 horas. Nestas condições, machos e fêmeas apresentaram valores de H intermediários aos valores teóricos de H = 0 e H = 0,5 demonstrando que para esta espécie, a curva de sobrevivência é do tipo retangular. A distribuição da mortalidade por idade específica indicou que a força desse parâmetro age de dois modos sobre os adultos desta espécie. Em um, a mortalidade tem maior força nos intervalos compreendidos entre a emergência dos adultos e o 10° dia após este processo. No segundo modo, a força de mortalidade é maior entre o 20° e 30° dias após a emergência, sendo que pequenas variações na mortalidade causam maior impacto na sobrevivência das fêmeas do que nos machos.

Entropy estimation in Muscina stabulans (Fallén) (Diptera, Muscidae) under laboratory conditions. Entropy (H) as a concept in demography was adapted from that of physics to quantify the impact of mortality on life expectancy and to quantitatively demonstrate mortality tendencies in experimental populations. Entropy was estimated for 160 pairs of Muscina stabulans (Fallén, 1817) in a climate-controlled chamber (24.8°C ± 0.6°C, relative humidity 70 - 80 percent, 12 h photophase). Both sexes had H values intermediate to those theoretically expected (0.0 - 0.5), showing that the survival curve is rectangular. The age-specific mortality distribution shows that mortality affects adults of this species in two ways. First, mortality is higher for 10 days from pupal emergence. Second, mortality again increases between 20-30 days after emergence. Small differences in mortality rates cause a greater overall impact on the survival of females.

Desenvolvimento de Ophyra albuquerquei Lopes (Diptera, Muscidae) em condições de laboratório / Development of Ophyra albuquerquei Lopes (Diptera, Muscidae) in laboratory conditions

Ophyra albuquerquei may often be a potential predator of Musca domestica Linnaeus, 1758 in poultry and pig houses in southern Brazil. Here we address the developmental period of immatures stages and their viability. To obtain eggs, larvae and pupae, a colony was established in the laboratory. Adult flies were fed on a diet comprising two parts dry milk, two parts sugar and one part fish flour. Larval diet comprised one part fish flour and one part sawdust and water. The eggs, larvae and pupae were incubated at 26° ± 1°C, 75 percent ± 10 percent R.H. and 12 h photoperiod. The egg to adult cycle took 573 h with a total viability of 64 percent. The shortest of the stages was the egg stage, which lasted about 20 h. The larval stage had the lowest viability (about 82 percent) and longest time interval (279 h). Overall, the results of this study show that O. albuquerquei can be readily maintained in the laboratory.

Generalized status epilepticus associated with massive pulmonary aspiration and transient central diabetes insipidus: case report

Status epilepticus causes significant morbidity and mortality. A case of generalized status epilepticus followed by massive pulmonary aspiration, acute respiratory failure and transient central diabetes insipidus is presented. Seizures were promptly controlled, but the patient required mechanical ventilation and correction of polyuria with desmopressin acetate. During hospitalization mental status improved, diabetes insipidus spontaneously remitted and he was discharged without neurologic sequelae. The clinical and pathophysiological features of this case are discussed