Rearing bacteria and maggots concurrently: a protocol using Lucilia sericata (Diptera: Calliphoridae) as a model species

Maggot debridement therapy using live Lucilia sericata (Meigen) larvae is an efficient and cost-effective way to treat chronic wounds. The recent increase in studies to assess the antibacterial properties of L. sericata has created a need for a simple, low-cost, and comprehensible rearing and investigative method for researchers with little or no entomological experience. This paper describes and evaluates a reproducible protocol for sterilising and rearing blowfly larvae utilising two sterile artificial diets (blood–yeast agar and pre-prepared blood agar plates) that is suitable for directly investigating the effect of larvae on microbial growth. Using Lucilia sericata as a model, the results show that larval growth on the pre-prepared blood agar diet is detrimental to larval growth and survival, whereas larval growth and survival on the blood–yeast agar diet are comparable to those of larvae raised on porcine liver. This diet is proposed as a standard for blowfly and bacteria interaction studies investigating clinical microbial strains. Developmental data are provided for L. sericata larvae raised on both sterile and nonsterile diets so that researchers can determine the effect of treatment based on the length of time for larvae to reach the required life stage at 25 ± 2 °C. Information on larval ageing (instars at an average of 1, 2, 3 and 4 days), oviposition times (4–5 days after adult emergence) and adult longevity on the diets (102–116 days) is also given.     

Is aggregated oviposition by the blow flies Lucilia sericata and Phormia regina (Diptera: Calliphoridae) really pheromone‐mediated?

When female blow flies Lucilia sericata and Phormia regina (Diptera: Calliphoridae) oviposit in aggregations on carrion, even‐aged larval offspring reportedly develop faster, and fewer are parasitized or preyed upon. The benefits of aggregated oviposition equally affect con‐ and heterospecific larvae sharing a resource. The benefits imply that female blow flies engage in coordinated, pheromone‐mediated oviposition behavior. Yet, repeated attempts to identify oviposition pheromones have failed invoking doubt that they exist. Simply by regurgitating and feeding on carrion, flies may produce attractive semiochemicals. If flies were to aggregate in response to feeding flies rather than ovipositing flies, then the semiochemical cue(s) may be associated with the salivary gland. Working with L. sericata and P. regina and using liver as a surrogate oviposition medium, we test the hypotheses, and present data in their support, that (i) gravid or nongravid females ovipositing and/or feeding on liver enhance its attractiveness to gravid and nongravid females; (ii) females respond to semiochemicals from feeding heterospecific females; (iii) females respond equally well to semiochemicals from feeding con‐ and heterospecific females; (iv) macerated head tissues of females applied to liver enhance its attractiveness; and (v) females in direct contact with and feeding on liver, but not when next to yet physically separated from liver, enhance attraction of flies. We conclude that oviposition site‐seeking females do not respond to an oviposition pheromone. Instead, they appear to coopt semiochemicals associated with feeding flies as resource indicators, taking chances that resources are suitable for oviposition, and that ovipositing flies are present.     

Lifetime reproductive output of Calliphora vicina and Lucilia sericata in outdoor caged and field populations; flight vs. egg production?

Females of the blowflies Calliphora vicina (Robineau-Desvoidy) and Lucilia sericata (Meigen) (Diptera: Calliphoridae) maintained in sheltered outdoor cages and supplied with excess food, oviposited later than would have been expected from the temperature-sum. The survival rates of the caged flies was high and the isolation of flies from predation, extreme temperatures and food shortages is likely to have contributed to this. Despite good survival rates, subsequent egg production over the greater part of the adult life span was reduced to approximately 24% for C. vicina and approximately 55% for L. sericata, of the potential expected from the published temperature-sums required for the maturation of successive egg batches. The data suggest that under field-cage conditions there is a considerable variation in egg development between individuals of the same age and that this variation should not be overlooked, since it may have significant implications in ecological and forensic investigations; however, the cause of this variability remains unclear. While lower than expected, the reproductive outputs recorded in the cages were nevertheless considerably greater than those that have been estimated for blowflies in the field and illustrate the potential for population increase in these species under favourable conditions. The possibility of a greater energy investment in flight activity relative to reproductive output in C. vicina compared to L. sericata is proposed.     

Computer modelling of bone’s adaptation: the role of normal strain,shear strain and fluid flow

Bone loss is a serious health problem. In vivo studies have found that mechanical stimulation may inhibit bone loss as elevated strain in bone induces osteogenesis, i.e. new bone formation. However, the exact relationship between mechanical environment and osteogenesis is less clear. Normal strain is considered as a prime stimulus of osteogenic activity; however, there are some instances in the literature where osteogenesis is observed in the vicinity of minimal normal strain, specifically near the neutral axis of bending in long bones. It suggests that osteogenesis may also be induced by other or secondary components of mechanical environment such as shear strain or canalicular fluid flow. As it is evident from the literature, shear strain and fluid flow can be potent stimuli of osteogenesis. This study presents a computational model to investigate the roles of these stimuli in bone adaptation. The model assumes that bone formation rate is roughly proportional to the normal, shear and fluid shear strain energy density above their osteogenic thresholds. In vivo osteogenesis due to cyclic cantilever bending of a murine tibia has been simulated. The model predicts results close to experimental findings when normal strain, and shear strain or fluid shear were combined. This study also gives a new perspective on the relation between osteogenic potential of micro-level fluid shear and that of macro-level bending shear. Attempts to establish such relations among the components of mechanical environment and corresponding osteogenesis may ultimately aid in the development of effective approaches to mitigating bone loss.     

A new species of Anthodiscus (Caryocaraceae) from Chocó, Colombia

The first record ofAnthodiscus from the rain forest of Pacific coastal Colombia is the new speciesA. chocoensis which is described here. The distribution of the genus is discussed in relation to its recent discovery in both the Chocó and the coastal forests of eastern Brazil.     

A new species of Apechoneura Kriechbaumer (Hymenoptera, Ichneumonidae, Labeninae) from Colombia

A new species of the ichneumonid subfamily Labeninae, Apechoneura seminigrasp. n., is described. Specimens were collected from the Amazon Rainforest of Colombia.     

Conversion of the BASE prion strain into the BSE strain: the origin of BSE?

Atypical neuropathological and molecular phenotypes of bovine spongiform encephalopathy (BSE) have recently been identified in different countries. One of these phenotypes, named bovine "amyloidotic" spongiform encephalopathy (BASE), differs from classical BSE for the occurrence of a distinct type of the disease-associated prion protein (PrP), termed PrP(Sc), and the presence of PrP amyloid plaques. Here, we show that the agents responsible for BSE and BASE possess different biological properties upon transmission to transgenic mice expressing bovine PrP and inbred lines of nontransgenic mice. Strikingly, serial passages of the BASE strain to nontransgenic mice induced a neuropathological and molecular disease phenotype indistinguishable from that of BSE-infected mice. The existence of more than one agent associated with prion disease in cattle and the ability of the BASE strain to convert into the BSE strain may have important implications with respect to the origin of BSE and spongiform encephalopathies in other species, including humans.     

First report of Triatoma nigromaculata (Stål, 1859) (Hemiptera, Reduviidae, Triatominae) for Colombia

The presence of Triatoma nigromaculata was recorded for the first time in Colombia in the rural village La Playa in the province of Cauca. A single female was captured from an outdoor area near a household. The presence of Trypanosoma parasites in the specimen was not established due to the poor condition of the specimen. The epidemiological importance of this finding is discussed with respect to the potential for transmission of Chagas disease in the province of Cauca and, more broadly, in Colombia.     

Food habits of Puma concolor (Carnivora: Felidae) in the Parque Nacional Natural Puracé, Colombia

Neotropical puma (Puma concolor) diet is scarcely known, in particular that of mountain dwelling individuals from Northern South America. This is the first study on pumas from the paramo and the first puma diet analysis for Colombia. The puma diet was studied from 2007 to 2009 in the Puracé National Park in the South Colombian Andes. Paramos are unique neotropical high altitude ecosystems which store and regulate water, and are currently threatened by agricultural expansion and climate change. Seven latrines were monitored for three years and scat collected, washed and dried. Items in scat such as hair, bones, claws and others were separated. Hairs were inspected by microscopy and compared to voucher hair museum specimens. Bone fragments, claws and teeth were also compared to museum collections and identified wherever possible. Additionally, six cameras were set along game trails to document puma and potential prey presence in the area. Food items from five species were identified in 60 puma scats; Northern Pudu (Pudu mephistophiles) was the most important prey in their diet. A total of 354 camera trap-nights photographed a male and female puma, Northern pudu and Spectacled bear (Tremarctos ornatus). The main conclusion suggests a strong dependence of puma on the threatened and mysterious Northern Pudu in paramo habitats. This behavior might reflect restricted prey availability in the high Andes mountains of Colombia, and highlights the plasticity in the puma diet. Conservation actions in the paramo should thus, focus on focal wild species, and in particularly those that show a relationship, such as the one evidenced here with the dependence of puma on Northern Pudu. These findings contribute to increase the little known ecology of Andean puma populations and the species as a whole in Colombia. Baseline data on puma prey populations in different ecosystems throughout their range, is critical to understand the regional requirements for survival, and design conservation actions, to follow and evaluate the need for particular protected areas along their geographical gradients.     

Diet of the capybara Hydrochaeris hydrochaeris (Rodentia: Hydrocharidae) in Caño Limón, Arauca, Colombia

We studied the composition and seasonal variation of the diet of the capybara (Hydrochaeris hydrochaeris) in the flooded savannas of Ca?o Limón, Colombia. This was achieved by direct observation of the consumption patterns of these animals. The capybaras only consumed plants, and their diet included 89 species of 22 families. Sixty three percent of these plant species had not been reported before. The most commonly consumed plants (94% of the diet), belonged to the Poaceae, Cyperaceae, Leguminosae and Pontederiaceae. Only seven species represented 60% of the total diet: the grasses Hymenachne amplexicaulis (16.9%), Digitaria bicornis (4.5%) and Panicum maximum (4.4%) and the Cyperaceae Rynchospora corymbosa (4.4%). There was seasonal variation in the diet composition of capybaras.     

Historical, social and epidemiological roots of tuberculosis in Bogotá, Colombia

Understanding the current epidemiologic dynamic of tuberculosis (TB) in any society requires a holistic approach. In the current paper, the history and behavior of the TB is summarized for Bogotá, Colombia. In prehispanic periods the occurrence of TB was low. During the Conquest and the Colony periods, a moderate increase of pulmonary and abdominal TB was observed. In the 1870s, a great increase in cases of pulmonary TB was associated with the accelerated urbanization process. Since the 1920s, the occurrence of pulmonary TB shifted to the status of an endemic disease. After 1920, its occurrence was relatively steady until the 1970s, when its occurence greatly decreased. More recently, however, an increase in case numbers has been observed. The occurrence of TB in each period is associated with clearly defined social and environmental phenomena.     

Genetic variability of Brycon henni (Characiformes: Characidae) in the middle basin of Nare and Guatapé Rivers, Magdalena River system, Colombia

Brycon henni is a native species in Magdalena's River basin, and because of its cultural and economic importance, is strongly overexploited. This study aimed to describe the genetic variability and population structure of this species from Nare and Guatapé rivers basins. A total of 195 individuals were collected and DNA extractions were obtained from muscle and blood tissue. Fourteen primers were evaluated with the RAPD technique, being four of them polymorphic, and produced 66 different fragments (63% polymorphism). Besides, using the molecular variance (AMOVA) analysis, the population structure was described for all sites (phi(ST) = 0.297, phi(ST) = 0.163; Nare and Guatapé river basins, respectively), and suggested the importance of the migratory behaviour of the species in the genetic differentiation. Genetic distances among sampled sites showed that most of the genetic differentiation occurred between sites Guatapé and El Cardal with respect to the others. A Mantel Test demonstrated a correlation between genetic and geographic distances (r = 0.431 both of the basins evaluated; r = 0.377, Nare river middle basin), and suggested isolation by distance. The outcomes obtained in this study have valuable implications in species conservation and the genetic variability of natural populations of B. henni, and should be complemented with morphological analyses.     

Research ethics: the case with the tule (kuna), Urabbá, Colombia

An ethical analysis was performed during the development of a research project titled "Culture, nourishment and malaria in the Kuna aboriginals of Urabá, Colombia." This project had 2 objectives; (1) to investigate the prevalence of malaria and its relationship with hypovitaminosis A and nutritional status, and (2) to understand the community's conceptions and practices towards malaria. The current paper summarizes reflections concerning the application of ethical principles and moral values during the course of the malaria research project. Two intercultural relationships were clearly defined: the culture of the Tule (Kuna) Indians, with a traditional medical system, and the culture of the research group, focused on the biomedical model. The rationale and the discussion proposed during the writing of the project proposal was presented as well as the dilemmas that developed during the project within the communities. These problems required rapid decision-making in situations for which the scientists had not been adequately prepared. A need was indicated for application of ethical principles to permeate the analysis throughout the research process in a horizontal manner, such that the human dignity of the participants and the ethnicity of the community are preserved above the purposes of the project. In the research process, mediation between the ethics of conviction and the ethics of consequences must take precedence, with both outcomes tied to an informed consent in place during the process. The establishment of national and local research ethics committees was indicated as necessary to preserve the lifestyle and culture of the ethnic groups. These values were seen as endangered given the trading pressures and health policies in a globalized world.     

Morphological analysis of three populations of Anopheles (Nyssorhynchus) nuneztovari Gabaldón (Diptera: Culicidae) from Colombia

Based on the results of comparative analyses of 1,039 specimens of several progenies of Anopheles nuneztovarifrom three localities in Colombia, eight costal wing spot patterns were observed. Patterns I and III were the most frequent: 77.96% and 11.36%, respectively. Using the diagnostic characters ratio of the length of the basal dark area of hind tarsomere II/length of hind tarsomere II, ratio of the length of the humeral pale spot/length of the pre-humeral dark spot, and the ratio of the length of the subcostal pale spot/length of the distal sector dark spot (DS-III2/Ta-III2, HP/PHD, SCP/DSD) approximately 5% of the adult females were misidentified as a species of Nyssorhynchus, different from An. nuneztovari. Approximately 5% of the specimens showed DS-III2/Ta-III2 ratio less than 0.25 (range 0.21 - 0.24), and among them 3.34% shared a HP/PHD ratio less than 1.50. Consequently, 1.52% of An. nuneztovari individuals can be misidentified as Anopheles oswaldoi. In those specimens with the DS-III2/Ta-III2 ratios higher than 0.25, 34.45% displayed SCP/DSD values greater than 0.50 and of these, 3.65% displayed HP/PHD values greater than 1.8. This combination of characters could lead one to misidentify samples of An. nuneztovari as Anopheles rangeli. Similarly, 2.43% of the females could be identified erroneously as either Anopheles aquasalis or Anopheles benarrochi. Individuals with a HP/PHD ratio greater than 2.0, could be misidentified as Anopheles trinkae, Anopheles strodei or Anopheles evansae. A distinct combination of diagnostic characters for An. nuneztovari from Colombia is proposed.     

Passalidae (Coleoptera: Scarabaeoidea) of the Biogeographical Province of Chocó and the West Andean Region of Colombia,with the Description of Two New Species

We present a synopsis of the Passalidae of the Chocó biogeographical province and the western slopes of the Western Andean range of Colombia as a result of field collections, examination of entomological collections, and review of the literature. We record a total of 41 species, provide an identification key, and, for the 39 species for which we were able to examine specimens, include a diagnosis and collecting data. Two new species of Passalus (Pertinax) are described and illustrated. The species of this region compose 42% of the passalid species known for Colombia. The richness of species and the high degree of endemism (34%) indicate the faunistic importance of this area, which is closely related to the fauna of lowland Central America.