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Larval therapy, the therapeutic use of blowfly larvae to treat chronic wounds, is primarily used in debridement. There are, however, gaps in current knowledge of the optimal clinical application of the therapy and mechanisms of action in the debridement process. Using an artificial assay, two studies were undertaken to investigate these aspects of larval debridement by Lucilia sericata Meigen (Diptera: Calliphoridae); the first studied the effects of the density of larvae on tissue digestion and larval mass, and the second considered the effects on the same parameters of incorporating protease inhibitors into the feeding substrate. The total mass of tissue digested increased with larval density until saturation was observed at 5.0-7.5 larvae/cm2. This range was considered optimal as lower doses resulted in the removal of less tissue and higher doses offered no additional tissue removal and appeared to exacerbate competition for feeding. In the second study, increased protease inhibitor concentration led to significant decreases in tissue digestion and larval mass, suggesting that serine proteases, particularly trypsin, may play major roles in larval digestion. Such information is important in elucidating the main constituents that make up larval digestive products and may be significant in the development of new therapies. [ABSTRACT FROM AUTHOR]

The subfamily Luciliinae is diverse and geographically widespread. Its four currently recognised genera (Dyscritomyia Grimshaw, 1901, Hemipyrellia Townsend, 1918, Hypopygiopsis Townsend 1916 and Lucilia Robineau-Desvoidy, 1830) contain species that range from saprophages to obligate parasites, but their pattern of phylogenetic diversification is unclear. The 28S rRNA, COI and Period genes of 14 species of Lucilia and Hemipyrellia were partially sequenced and analysed together with sequences of 11 further species from public databases. The molecular data confirmed molecular paraphyly in three species-pairs in Lucilia that hamper barcode identifications of those six species. Lucilia sericata and L. cuprina were confirmed as mutual sister species. The placements of Dyscritomyia and Hypopygiopsis were ambiguous, since both made Lucilia paraphyletic in some analyses. Recognising Hemipyrellia as a genus consistently left Lucilia s.l. paraphyletic, and the occasionally-recognised (sub)genus Phaenicia was consistently paraphyletic, so these taxa should be synonymised with Lucilia to maintain monophyly. Analysis of a matrix of 14 morphological characters scored for adults of all genera and for most of the species included in the molecular analysis confirmed several of these findings. The different degrees of parasitism were phylogenetically clustered within this genus but did not form a graded series of evolutionary stages, and there was no particular relationship between feeding habits and biogeography. Because of the ubiquity of hybridization, introgression and incomplete lineage sorting in blow flies, we recommend that using a combination of mitochondrial and nuclear markers should be a procedural standard for medico-criminal forensic identifications of insects. [ABSTRACT FROM AUTHOR]

An understanding of how arthropods use energy is fundamental to explaining their diverse life histories and adaptation to specific environments. It is also of importance when attempting to predict the impacts of environmental change on patterns of development and phenology. Here, lipid use by the economically important agent of ovine myiasis, Lucilia sericata ( Diptera: Calliphoridae), was quantified at a range of temperatures. During pupation, at temperatures above the minimum temperature required for development (9 °C), pupae depleted an average of 30% of their total lipid over the course of pupation regardless of temperature. There was no detectable loss of lipid during pupation at temperatures below 9 °C. In general, larger individuals had the same relative amounts of lipid as smaller individuals. Newly emerged adults metabolized about 16% of the lipid reserves with which they emerged in the first 24 h during flight-related activity. Starved adults, with access to water but without sucrose or protein, depleted their lipid reserves and died within about 4 days of emergence. However, adults with access to protein and/or carbohydrate were able to maintain a stored lipid content of about 2.38% of their total body mass for at least 14 days after emergence, irrespective of sex. This finding is similar to that in field-caught individuals, in which lipid content was found to be a mean of 3% of body mass. The data suggest that warmer environmental conditions, within the temperature limits tested here, although shortening the time required for development and altering the patterns of seasonal abundance of L. sericata, are unlikely to impact on fly survival because of greater metabolic demands during non-feeding stages of the lifecycle. [ABSTRACT FROM AUTHOR]

Background: The green bottle fly maggot, Lucilia sericata, is a species with importance in medicine, agriculture and forensics. Improved understanding of this species’ biology is of great potential benefit to many research communities. MicroRNAs (miRNA) are a short non-protein coding regulatory RNA, which directly regulate a host of protein coding genes at the translational level. They have been shown to have developmental and tissue specific distributions where they impact directly on gene regulation. In order to improve understanding of the biology of L. sericata maggots we have performed small RNA-sequencing of their secretions and tissue at different developmental stages. Results: We have successfully isolated RNA from the secretions of L. sericata maggots. Illumina small RNA-sequencing of these secretions and the three tissues (crop, salivary gland, gut) revealed that the most common small RNA fragments were derived from ribosomal RNA and transfer RNAs of both insect and bacterial origins. These RNA fragments were highly specific, with the most common tRNAs, such as GlyGCC, predominantly represented by reads derived from the 5’ end of the mature maggot tRNA. Each library also had a unique profile of miRNAs with a high abundance of miR-10-5p in the maggot secretions and gut and miR-8 in the food storage organ the crop and salivary glands. The pattern of small RNAs in the bioactive maggot secretions suggests they originate from a combination of saliva, foregut and hindgut tissues. Droplet digital RT-PCR validation of the RNA-sequencing data shows that not only are there differences in the tissue profiles for miRNAs and small RNA fragments but that these are also modulated through developmental stages of the insect. Conclusions: We have identified the small-RNAome of the medicinal maggots L. sericata and shown that there are distinct subsets of miRNAs expressed in specific tissues that also alter during the development of the insect. Furthermore there are very specific RNA fragments derived from other non-coding RNAs present in tissues and in the secretions. This new knowledge has applicability in diverse research fields including wound healing, agriculture and forensics. [ABSTRACT FROM AUTHOR]

First instars of Lucilia ampullacea Villeneuve, Lucilia caesar Linnaeus, Lucilia cuprina Weidemann, Lucilia richardsi Collin, Lucilia sericata Meigen and Lucilia silvarum Meigen (Diptera: Calliphoridae) are thoroughly documented with scanning electron microscopy images, light microscopy photographs and line drawings. The following morphological structures are documented: pseudocephalon, antennal complex, maxillary palpus, facial mask, cephaloskeleton, thoracic and abdominal spinulation, spiracular field, and posterior spiracles. New diagnostic features of the cephaloskeleton are presented and the spinulation of the abdominal segments is described. Earlier descriptions are summarized and major discrepancies with the current study are discussed. The present results allow for the clarification, correction and, especially, complementing existing information provided by numerous authors. The first instar larva of L. richardsi is described for the first time and an identification key to the first instars of European species of Lucilia Robineau-Desvoidy of forensic importance is presented. [ABSTRACT FROM AUTHOR]

In chronic wounds, it may be clinically important to remove extracellular bacterial and patient DNA as its presence may impede wound healing and promote bacterial survival in biofilm, in which extracellular DNA forms part of the biofilm architecture. As medicinal maggots, larvae of Lucilia sericata Meigen (Diptera: Calliphoridae) have been shown to efficiently debride wounds it became of interest to investigate their excretions/secretions (ES) for the presence of a deoxyribonuclease (DNAse) activity. Excretions/secretions products were shown to contain a DNAse, with magnesium, sodium and calcium metal ion dependency, and a native molecular mass following affinity purification of approximately 45 kDa. The affinity purified DNAse degraded genomic bacterial DNA per se, DNA from the slough/eschar of a venous leg ulcer, and extracellular bacterial DNA in biofilms pre-formed from a clinical isolate of Pseudomonas aeruginosa. The latter finding highlights an important attribute of the DNAse, given the frequency of P. aeruginosa infection in non-healing wounds and the fact that P. aeruginosa virulence factors can be toxic to maggots. Maggot DNAse is thus a competent enzyme derived from a rational source, with the potential to assist in clinical wound debridement by removing extracellular DNA from tissue and biofilm, and promoting tissue viability, while liberating proteinaceous slough/eschar for debridement by the suite of proteinases secreted by L. sericata. [ABSTRACT FROM AUTHOR]

Time between death and discovery of remains, or postmortem interval (PMI), can be assessed using blow fly maggot age. Forensic entomologists rely on published, often nonlocal, species-specific developmental tables to determine maggot age. In a series of common garden experiments, we investigated the developmental rate variation between populations of Lucilia sericata collected from Sacramento, CA, San Diego, CA, and Easton, MA at 16°C, 26°C, and 36°C. For the 16°C trial the time measurement started at egg hatch, while for the higher temperatures the experiment began at oviposition; the wandering stage signified the endpoint for all experiments. The distribution of developmental times differed significantly (ANOVA, p < 0.001) between the three populations within each temperature treatment. We discovered that regional variation of developmental times within a blow fly species exists. This study demonstrates the importance of assembling local population-specific developmental tables when estimating larval age to determine PMI. [ABSTRACT FROM AUTHOR]

Lucilia sericata maggots are used world-wide in biosurgery for the medical treatment of nonhealing wounds because they ingest necrotic tissues and significantly promote healing. To gain further insight into interdependencies between ecological adaptation and molecular evolution of innate immunity in Diptera, we used the suppression subtractive hybridization method to screen for genes that are differentially expressed in response to septic wounding of sterile second instar larvae of L. sericata. This approach resulted in the identification of 65 novel Lucilia genes including potential signalling proteins (e.g. inhibitor of apoptosis 2 protein) and a number of digestive enzymes including lipases and proteinases. Additionally, we found numerous putative antimicrobial peptides (AMPs), such as a potential Lucilia defensin, diptericin and three novel proline-rich AMPs. The identified genes may facilitate access to both peptides and proteins within the beneficial excretions, secretions and haemolymph of medicinal maggots and provide novel insights into the evolution of innate immunity in Diptera. [ABSTRACT FROM AUTHOR]

Abstract: Current evidence suggests that neo formation of the anabolic steroid boldenone (androsta-1,4-diene-17-ol-3-one) occurs in calves’ faecal material, making it difficult to distinguish between illegally administered boldenone and its potential endogenous presence. This strengthens the urgent need to elucidate the pathway leading to boldenone formation. In our laboratory, the invertebrate Neomysis integer (Crustacea, Mysidacea) was used since 2004 as an alternative model for the partial replacement of vertebrate animals in metabolisation studies with illegal growth promotors and veterinary drugs, e.g. boldenone. The present study evaluates the metabolic capacity of other invertebrates, the brine shrimp Artemia franciscana and maggots of the greenbottle fly Lucilia sericata. The first results indicate that maggots of L. sericata are able to convert phytosterols and –stanols, nowadays in substantial amounts added to animal feed, into androsta-1,4-diene-3,17-dione (ADD), the precursor of boldenone, at a yield of 0.10–0.14% (p <0.001, significance compared to endogenous excretion of maggots) but not to boldenone itself. Furthermore, β-testosterone, an endogenous hormone, was transformed into androst-4-ene-3,17-dione (AED), ADD and β-boldenone at a significant (p <0.001, significance compared to endogenous excretion of maggots) yield of circa 13%, 0.80% and 2.2%, respectively. In future studies these results are of value to further evaluate the use of maggots of L. sericata as an invertebrate model in metabolisation studies. [Copyright &y& Elsevier]

The resurgence of larval biotherapy as a debridement tool in wound management has been accompanied by several clinical reports highlighting concomitant tissue regeneration. Studies employing in vitro cell motility assays have found that purified excretory/secretory (ES) products from Greenbottle larvae (blowfly, Lucilia sericata) are motogenic for human dermal fibroblasts when used as a supplement in culture media. The objective of the present study was to determine whether ES delivered using a prototype hydrogel wound dressing induced similar motogenic effects on fibroblastic (3T3) and epithelial cells (HaCaTs) comprising a scratched-monolayer wound model. Quantitative analysis by MTT assay failed to detect significant mitogenic effects of ES on either cell type. Quantitative image analysis revealed that ES exposure markedly accelerated wound closure through a motogenic effect on both fibroblasts and keratinocytes. Quantitative histochemical analysis detected significantly higher phosphotyrosine (pTyr) expression in ES-exposed cell cultures than in controls; moreover immunocytochemistry revealed conspicuously raised levels of pTyr expression in cells located at the wound margin. By attenuation with a panel of enzyme inhibitors these effects were attributed to the protease components of ES. The present results suggest that controlled delivery of ES as a follow-up to maggot debridement therapy may be an effective therapeutic option for stimulation of tissue regeneration in wound management. [ABSTRACT FROM AUTHOR]

Glycosylation and sulfation are two of the essential post-translational modifications of proteins. The slalom gene encodes a 3′-phosphoadenosine 5′-phosphosulfate transporter, a conserved protein found in organisms as diverse as plants and humans and required for sulfation of proteins. In Drosophila, slalom is exclusively expressed in salivary glands, which is unexpected, taken into account the general function for sulfation of proteins. In this paper, we present a detailed description of the slalom gene in a large insect, the blowfly Lucilia sericata. Our data demonstrate that the slalom gene structure, the protein and the expression pattern are highly conserved between Lucilia and Drosophila. Lucilia slalom promoter analysis, using transgenic Drosophila, demonstrates that the Lucilia slalom promoter can faithfully mimic the expression pattern of both Lucilia and Drosophila slalom in salivary glands. Taken together, these data show the structure and the transcriptional cis-regulatory elements of the slalom gene to be unchanged during evolution, despite the 100 million years of divergence between the two insects. Moreover, it suggests that the salivary gland-specific expression of slalom bears an important and conserved function for sulfation of specific macromolecules. [ABSTRACT FROM AUTHOR]

Species richness, abundance relations, exploitation efficiencies, and population dynamics were examined within four carrion fly communities from a small isolated island in the Baltic to the large island of Åland. A total of 23 species and 11408 Specimens were collected. Species richness (studied by rarefaction) of potential carrion flies was lowest on the small isolated island, but the smallest number of species emerged from the second largest island. Lucilia illustris Meig. was the most numerous species at every site, comprising 46-56% of the potential breeders and 71-91% of the emerging flies. Exploitation efficiency, measured by the numbers of individuals emerging per gram of carrion, was highest on the smallest island, but faunal similarity and ordination analyses suggest that competition was more intense on the larger islands. [ABSTRACT FROM AUTHOR]

Species composition and abundance relations of flies attracted to and bred from different sizes (20-100 g) and types of carrion (small mammal, cow liver, bird, and fish) were studied experimentally in natural breeding conditions in South Finland. Large pieces of carrion did not attract significantly more individuals or species than did small ones, but there was a positive correlation between size of carrion and numbers of flies bred, apparently because of competition. Altogether 10 species emerged from 50 cultures, and on average 2,78 ± 1,22 (SD) species emerged from one culture. The number of co-occurrences among the emerging flies indicated random colonization. Variation in species composition between like pieces of carrion was not less than variation between carcasses of different size or type; hence, size and type of carrion are not important determinants of community structure within the size and type ranges used. Lucilia illustris (Meig) was the predominant species, comprising 50% of flies trapped and 85% of flies bred. The difference indicates changing species composition in the community. Two sets of cultures were left open for egg-laying for 2 and 7 d. Competition was less intensive in the former cultures, which produced 4,0 individuals per gram of carrion, contrasting with only 1.4 individuals per gram in the latter cultures. Competition delayed development in all species, but least in L. illusiris, which suggests that fast developing species are at a competitive advantage. In agreement with this, abundance was positively correlated with (he rate of development. [ABSTRACT FROM AUTHOR]

The article offers information on larval therapy and its clinical application. The use of larval therapy, also known as biosurgery or maggot therapy, dates back to ancient civilisations, and stemmed from early observations of the therapeutic effects of opportunistic larval infestation. The larvae from green bottle fly Lucilia sericata are mainly used for wound care. It is currently used to treat chronic soft tissue wounds, including neurovascular ulcers, venous stasis wounds, pressure ulcers, traumatic and surgical wounds, burns and necrotic tumours.

The article presents the results of a preliminary observational study on using larval therapy to eliminate methicillin-resistant staphylococcus aureus (MRSA) from diabetic foot ulcers. The study included the application of sterile free-range larvae of the green bottle fly Lucilia Sericata to the MRSA-colonized ulcers. The results showed a reduction in sloughy necrotic tissue and an increase of granulation tissue. The results also confirmed the potential of the therapy as a noninvasive and risk-free treatment for MRSA.

Determines the ability of an in vivo anticoccidial assay to identify potential feed-through insecticides using first-instar Lucilia sericata. Insect growth regulator, Cyromazine; Fipronil; Permethrin; Larval immobility; Dose-response; Tolerance.