Incidence of myiasis in Panama during the eradication of Cochliomyia hominivorax (Coquerel 1858, Diptera: Calliphoridae) (2002-2005)

We present the results of a study on myiasis in Panama during the first years of a Cochliomyia hominivorax eradication program (1998-2005), with the aim of investigating the behavior of the flies that produce myiasis in animals and human beings. The hosts that registered positive for myiasis were cattle (46.4%), dogs (15.3%), humans (14.7%), birds (12%), pigs (6%), horses (4%), and sheep (1%). Six fly species caused myiasis: Dermatobia hominis (58%), Phaenicia spp. (20%), Cochliomyia macellaria (19%), Chrysomya rufifacies (0.4%), and maggots of unidentified species belonging to the Sarcophagidae (3%) and Muscidae (0.3%). With the Dubois index, was no evidence that the absence of C. hominivorax allowed an increase in the cases of facultative myiasis.

Ultrastructure of the male terminalia of Cochliomyia hominivorax and C. macellaria

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.

Comparative morphology of the spermathecae of some species of Chrysomya Robineau-Desvoidy and Cochliomyia Townsend (Diptera, Calliphoridae)

Comparative morphology of the spermathecae of some species of Chrysomya Robineau-Desvoidy and Cochliomyia Townsend (Diptera, Calliphoridae). Little is known about the morphology of the chitinized structures of the spermathecae of the Calliphoridae. In this work, the spermathecae of Chrysomya albiceps Wiedemann, 1819, C. megacephala Fabricius, 1794, Cochliomyia macellaria Fabricius, 1775 and C. hominivorax Coquerel, 1858 are described and illustrated. The occurrence in one species of four spermathecae, an atypical form for blow flies, was recorded for the first time. The analysis of these structures will allow a better understanding of this group as well as provide taxonomic characters for future phylogenetic studies.

Treatment of oral myiasis caused by Cochliomyia hominivorax: two cases treated with ivermectin

The term myiasis is applied to the injurious action that larvae of certain diptera Cause to the organism of Vertebrate animals in the living or dead tissue in which they grow. Because of its great destructive potential. appropriate and preventative treatment are necessary. Among, the sites of infestation. the human mouth is a common site. mainly in tropical countries. We present two cases of oral myiasis Caused by Cochliomyia hominivorax spp. Ivermectin is all extremely effective semi-synthetic macrolides, in the treatment of, this condition. (C) 2008 The British Association of Oral and Maxillofacial Surgeons. Published by Elsevier Ltd. All rights reserved.

Influência do aumento do número de pupas hospedeiras de Cochliomyia macellaria (Diptera, Calliphoridae) no desenvolvimento do parasitóide Nasonia vitripennis (Hymenoptera, Pteromalidae) em laboratório

O desenvolvimento pós-embrionário, a produtividade, a taxa de parasitismo e a razão sexual de Nasonia vitripennis (Walker, 1836) criada em pupa de Cochliomyia macellaria (Fabricius, 1775) foram estudados. Densidades diferentes de hospedeiro foram usadas (proporções 1:1, 1:2, 1:3, 1:4 e 1:5) com tempo de exposição de 72 horas, em cada uma delas. Fêmeas nulíparas originárias da colônia estoque foram individualizadas em tubos de teste cobertos com algodão hidrófobo e contendo as pupas hospedeiras. Cada tratamento constituiu-se de 10 repetições. Depois da exposição, as vespas foram descartadas e as pupas hospedeiras foram individualizadas em tubos de teste até a emergência dos adultos de C. macellaria ou N. vitripennis. Amostras das pupas hospedeiras não expostas ao parasitismo e recebendo o mesmo tratamento experimental foram usadas como controle. Os parasitóides mostraram um desenvolvimento mais lento em relação ao aumento da densidade de hospedeiros. Houve uma diminuição na produção de parasitóides por hospedeiro em densidades elevadas. A razão sexual tendeu para um desvio para nascimento de fêmeas com o aumento da densidade do hospedeiro. Os índices de parasitismo mostraram uma diminuição quando o parasitóide foi exposto a mais de duas pupas hospedeiras.

Larval dispersal and predation in experimental populations of Chrysomya albiceps and Cochliomyia macellaria (Diptera: Calliphoridae)

In this study we investigated the larval dispersal associated with larval predation in experimental populations of Chrysomya albiceps and Cochliomyia macellaria. Frequency distribution of sampling units (G test) in the substrate was used to evaluate variation in larval dispersal. An experimental acrylic channel (1 x 0.1 x 0.2 m) covered with wood shavings was used to observe larval dispersal prior to pupation. The acrylic channel was graduated at 0.05 m intervals, each representing a sampling unit; hence, 20 sampling units were set up. A Petri dish containing third instar larvae of single and double species was deposited at one edge of the acrylic channel allowing larvae to disperse. The number of buried pupae (0, 1, 2, …n) present in each sampling unit was recorded. For double species, the number of recovered larvae of C. albiceps was similar to the number initially released on the dish Petri. On the other hand, the number of recovered larvae of C. macellaria was significantly smaller than the initially released number. The results show that C. albiceps attacks C. macellaria larvae during the larval dispersal process. The larval distribution of C. albiceps did not differ significantly from C. macellaria in double species, but it differed significantly in single species. The larval aggregation level of C. macellaria decreased when C. albiceps was present and the larval aggregation level of C. albiceps increased when C. macellaria was present. The implications of such findings for the population dynamics of these species are discussed.

Larval dispersal and predation in experimental populations of Chrysomya albiceps and Cochliomyia macellaria (Diptera: Calliphoridae)

In this study we investigated the larval dispersal associated with larval predation in experimental populations of Chrysomya albiceps and Cochliomyia macellaria. Frequency distribution of sampling units (G test) in the substrate was used to evaluate variation in larval dispersal. An experimental acrylic channel (1 x 0.1 x 0.2 m) covered with wood shavings was used to observe larval dispersal prior to pupation. The acrylic channel was graduated at 0.05 m intervals, each representing a sampling unit; hence, 20 sampling units were set up. A Petri dish containing third instar larvae of single and double species was deposited at one edge of the acrylic channel allowing larvae to disperse. The number of buried pupae (0, 1, 2, n) present in each sampling unit was recorded. For double species, the number of recovered larvae of C. albiceps was similar to the number initially released on the dish Petri. on the other hand, the number of recovered larvae of C. macellaria was significantly smaller than the initially released number. The results show that C. albiceps attacks C. macellaria larvae during the larval dispersal process. The larval distribution of C. albiceps did not differ significantly from C. macellaria in double species, but it differed significantly in single species. The larval aggregation level of C. macellaria decreased when C. albiceps was present and the larval aggregation level of C. albiceps increased when C. macellaria was present. The implications of such findings for the population dynamics of these species are discussed.

Larval dispersal and predation in experimental populations of Chrysomya albicieps and Cochliomyia macellaria (Diptera : Calliphoridae)

In this study we investigated the larval dispersal associated with larval predation in experimental populations of Chrysomya albiceps and Cochliomyia macellaria. Frequency distribution of sampling units (G test) in the substrate was used to evaluate variation in larval dispersal. An experimental acrylic channel (1 x 0.1 x 0.2 m) covered with wood shavings was used to observe larval dispersal prior to pupation. The acrylic channel was graduated at 0.05 m intervals, each representing a sampling unit; hence, 20 sampling units were set up. A Petri dish containing third instar larvae of single and double species was deposited at one edge of the acrylic channel allowing larvae to disperse. The number of buried pupae (0, 1, 2,...n) present in each sampling unit was recorded. For double species, the number of recovered larvae of C. albiceps was similar to the number initially released on the dish Petri. on the other hand, the number of recovered larvae of C. macellaria was significantly smaller than the initially released number the results show that C. albiceps attacks C. macellaria larvae during the larval dispersal process. The larval distribution of C. albiceps did not differ significantly from C. macellaria in double species, but it differed significantly in single species. The larval aggregation level of C. macellaria decreased when C. albiceps was present and the larval aggregation level of C. albiceps increased when C. macellaria was present. The implications of such findings for the population dynamics of these species are discussed.

Myiasis in Palate by Cochliomyia hominivorax

Myiasis is the infestation of tissues and organs of animals and humans caused by the larvae of certain dipteran flies. It is more common in undeveloped and tropical countries and usually affects elderly patients, persons who are sick, and patients with mental illness. Oral myiasis is a rare pathologic condition and a risk to the patient's life because of its great destructive potential. Therefore, appropriate treatment is necessary. This article aimed to report a case of myiasis caused by Cochliomyia hominivorax in the palate of a patient with primary progressive aphasia, which was successfully treated through mechanical removal of larvae plus administration of ivermectin.

Oftalmomiíase externa causada por cochliomyia hominivorax

The purpose of this study was to report a case of external ophthalmomyiasis caused by Cochliomyia hominivorax in a 10 years-old child, which presented acute preseptal celulitis and had 17 worms removed from the lacrimal canaliculus and conjunctival cul de sac, bilaterally, with resolution. The authors discuss the diagnosis and treatment of this nosological entity.

Atividade terapêutica do spinosad contra larvas de Cochliomyia hominivorax (L1, L2 e L3) em bovinos infestados natural e artificialmente

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Ivermectina e abamectina em diferentes doses e vias de aplicação contra larvas de Cochliomyia hominivorax em bolsas escrotais de bovinos recém-castrados, provenientes da região sudeste do Brasil

The preventive efficacy of ivermectin and abamectin administered in different routes (subcutaneous, intramuscular and pour-on) and doses (200 and 500mcg kg(-1)) against Cochliomyia hominivorax in the scrotal sac of cattle after castration, was evaluated. Animals from six different farms, in the state of Sao Paulo and Minas Gerais, Brazil were used. For each study, 3045 uncastrated bulls, depending on the number of groups, were selected. On day zero of the study, the procedure was carried out by the method of bloody castration and the animals were treated after this process. The efficacy of ivermectin and abamectin administered via the pour-on (500mcg kg(-1)), subcutaneous (200mcg kg(-1)) as well as the efficacy of abamectin intramuscularly (200mcg kg(-1)) were evaluated. In each experiment, one group of animals was kept as control. The animals were evaluated from the 3rd to the 14th day after castration process/treatment. The efficacy values for both active principles were <= 30% the next day 10 post-treatment (PT), and in five experiments, both ivermectin and abamectin, regardless of the route of administration, were ineffective (0.0%) on the day 10th PT. Based on the results found in this study, conducted in different properties from southeastern Brazil, both ivermectin and abamectin, when used the protocol presented, were considered ineffective in preventing scrotal myiasis in bulls, irrespective of the route of administration and dose used.

Rara miasis maxilar por Cochliomyia hominivorax: reporte de caso, actualidad y entomología

La miasis maxilar es un raro padecimiento tropical y endémico de varias zonas del mundo, propio de algunos mamíferos, y el hombre no es la excepción. A continuación presentamos el primer reporte de miasis de este tipo en Ecuador, caracterizamos una masiva invasión larvaria y analizamos casos similares reportados en la literatura médica.

Deep sequencing of New World screw-worm transcripts to discover genes involved in insecticide resistance

Background: The New World screw-worm (NWS), Cochliomyia hominivorax, is one of the most important myiasis-causing flies, causing severe losses to the livestock industry. In its current geographical distribution, this species has been controlled by the application of insecticides, mainly organophosphate (OP) compounds, but a number of lineages have been identified that are resistant to such chemicals. Despite its economic importance, only limited genetic information is available for the NWS. Here, as a part of an effort to characterize the C. hominivorax genome and identify putative genes involved in insecticide resistance, we sampled its transcriptome by deep sequencing of polyadenylated transcripts using the 454 sequencing technology. Results: Deep sequencing on the 454 platform of three normalized libraries (larval, adult male and adult female) generated a total of 548,940 reads. Eighteen candidate genes coding for three metabolic detoxification enzyme families, cytochrome P450 monooxygenases, glutathione S transferases and carboxyl/cholinesterases were selected and gene expression levels were measured using quantitative real-time polymerase chain reaction (qRT-PCR). Of the investigated candidates, only one gene was expressed differently between control and resistant larvae with, at least, a 10-fold down-regulation in the resistant larvae. The presence of mutations in the acetylcholinesterase (target site) and carboxylesterase E3 genes was investigated and all of the resistant flies presented E3 mutations previously associated with insecticide resistance. Conclusions: Here, we provided the largest database of NWS expressed sequence tags that is an important resource, not only for further studies on the molecular basis of the OP resistance in NWS fly, but also for functional and comparative studies among Calliphoridae flies. Among our candidates, only one gene was found differentially expressed in resistant individuals, and its role on insecticide resistance should be further investigated. Furthermore, the absence of mutations in the OP target site and the high frequency of mutant carboxylesterase E3 indicate that metabolic resistance mechanisms have evolved predominantly in this species.