Chrysomya Megacephala Larvae Research Articles

Using fly larvae to convert food waste for growing Oujiang color common carps: health risk assessment of polycyclic aromatic hydrocarbons.

The present study used Chrysomya megacephala larvae (CML) to transform food waste into safe and high-quality fish feed to substitute fish meal as a source of protein for growing Oujiang color common carps followed by a human health risk assessment of polycyclic aromatic hydrocarbons (PAHs). The results showed the ∑PAH concentration in the CML fed with food waste ranged from 50 to 370μgkg-1, and the most abundant PAH compound in the CML was BaP, contributing 59-84% of ∑PAHs. The Pearson correlation analysis results indicated no correlation between the ∑PAH concentrations and the culture substrate ratio (p > 0.05). Concentrations of BaP in the CML decreased with the increase of breeding density (p < 0.01). The residues as organic fertilizers have no potential ecological risk for PAHs. The biotransformed larva meal was used to partially or completely replace the fish meal as supplementary protein in the experimental feeds (T0, 0%; T50, 50%; T100, 100%). No significant difference (p < 0.05) of survival rate, lipid, and protein content in Oujiang color common carp was noted among T0, T50, and T100 fish feeds. Concentrations of ∑PAHs in Oujiang color common carp fed with the CML fish feeds all met the food safety standards in the European Union (EU). Furthermore, the consumption of Oujiang color common carps fed with the CML feed does not pose any health risks of PAHs for humans.

The anti-bacterial of whole body homogenates of third instar larvae of Chrysomya megacephala (Diptera:Calliphoridae) against different bacterial strains

The anti-bacterial of whole body homogenates of third instar larvae of Chrysomya megacephala (Diptera:Calliphoridae) against different bacterial strains

Potential application of Gustatory Receptor 1 (CmegGr1) gene as a molecular marker for identification of Chrysomya megacephala (Diptera: Calliphoridae).

Chrysomya megacephala larvae can easily be identified using cheap traditional microscopy techniques. Nevertheless, identification using taxonomy keys may be hampered, if the morphological characteristics of the larvae are incomplete, or immature for microscopic identification. To overcome the difficulty of species determination, molecular identification has gained relevance and is applied in forensic investigations. This study aimed to identify a novel target gene, known as the gustatory receptor 1 gene (CmegGr1), which has never been used for identification. The third instar larvae of Ch. megacephala (n = 30) and eight other forensically important fly species were obtained from two sources; rabbit carcasses and the Forensic Entomology Unit collection. Their DNAs were extracted and the CmegGr1 gene was amplified using polymerase chain reaction (PCR). The resulting sequences were subjected to phylogenetic analysis. A 209 bp fragment of the CmegGr1 gene was successfully amplified in 80% (24/30) of Ch. megacephala samples, while all of the non-Ch. megacephala species were not amplified. The phylogenetic analysis revealed that the evolutionary tree of CmegGr1 shares many traits with the 21a gustatory receptors of Calliphora stygia and Lucilia cuprina (Gr21a), which are also classified as necrophagous fly species. The high specificity of species identification was demonstrated in the present study using DNA barcoding, which led to the conclusion that the CmegGr1 gene could serve as an alternative marker for identifying Ch. megacephala.

Crystal and solution structures of a novel antimicrobial peptide from Chrysomya megacephala.

Antimicrobial peptides (AMPs) are small amphipathic peptides that exhibit bactericidal activity against a wide range of pathogenic microorganisms and are considered to be potential substitutes for antibiotics effective against microbial infection. PSK, an 84-amino-acid AMP recently isolated from Chrysomya megacephala larvae, probably belongs to the mitochondrial ATPase inhibitor family according to its sequence. No member of this family from an insect has been structurally characterized to date. In this study, the crystal structure of full-length PSK determined by molecular replacement using an ab initio modeled ensemble as a search model and a solution structure obtained from small-angle X-ray scattering (SAXS) measurements are reported. The crystal structure reveals a distinct fold compared with those of homologous peptides, in that PSK comprises two antiparallel α-helices rather than a single long helix, which is in good agreement with the SAXS-based ab initio model. However, the peptide exists as a monomer in solution, even though a stable dimer was observed in the crystal structure. This apparent contradiction may reflect different oligomerization states that may be implicated in its bioactivity. The data presented here have established a solid basis for further mechanistic studies of this novel insect AMP.

Effect of the medicinal plant Withania somnifera on the development of a medico-veterinary pest Chrysomya megacephala (Diptera: Calliphoridae)

ABSTRACT Topical administration of root and seed extracts (5, 10, 15 and 20 µg/µL) of Withania somnifera to 0, 1, 2, and 3 days post-moult third instar larvae of Chrysomya megacephala resulted in disruption of moulting and metamorphosis. This leads to several developmental aberrations, such as prolongation of larval-pupal and pupal-adult ecdysis, larval mortality, abnormal pupariation, formation of pupal-adult mosaics and adultoids, ecdysial failure, reduced pupariation and adult emergence. Treatment with seed extracts of W. somnifera was more effective as it causes greater toxicity in all the treated groups as compared to that observed with the root extracts. There was a significant interaction among all three factors viz. extract type (root and seed extracts), larval stage (0, 1, 2, 3 days post-moult third instar larvae) and concentration (5 µg/µL, 10 µg/µL, 15 µg/µL, 20 µg/µL) for prolongation of larval-pupal and pupal-adult ecdysis. The results are similar to those observed with the administration of juvenoids and hence it can be inferred that the plant extracts mimic the action of juvenoids. The results clearly suggest that W. somnifera acts as a potential IGR disrupting the moulting and metamorphosis as a consequence of interference with the normal hormonal mechanism in C. megacephala. Abbreviations: Co Sf=coarse surface; Cy W=cylindrical wings; De Ae = deformed anterior end; De W = deformed wings; Ev G = everted genitalia; Ev Pt = everted ptilinium; L Mp = larval mouth parts; Nm W = non-membranous wings; P Ab = pupal abdomen; P Cu = pupal cuticle; Pa T L = partial tanned legs; Pg E = pigmented eyes; Pm = puparium; Re W = reduced wings; Sr G = scar of genitalia; T Pm = tanned puparium; Tu L = tubular legs; Tw Pm = twisted puparium; Un Ab = untanned abdomen; Un Pm = untanned puparium; W Pri = wing primordia

Evaluation of Larval Therapy Compared to Antibiotic Therapy in the Treatment of Skin Wounds in Rabbits.

Larval therapy (LT) is a therapeutic modality that uses larvae of necrophagous flies for the treatment of wounds. The use of this therapy presents several benefits, due to the action of the larvae that remove necrotic tissue selectively, exercising antimicrobial action, and promoting healing. There are situations in which LT proves to be the only or the best alternative for the patient, such as wounds infected by multidrug-resistant microorganisms or when treatment difficulties may lead to an indication for amputation. The purpose of this study was to compare the efficiency of LT, using larvae of Chrysomya megacephala, with that of antibiotic therapy in the treatment of cutaneous wounds infected with Pseudomonas aeruginosa. Twenty-four rabbits were used to perform the experiment, distributed in four groups: group 1, induced wound without bacterial infection; group 2, induced wound with bacterial infection; group 3, induced wound with bacterial infection and antibiotic therapy; group 4, induced wound with bacterial infection and LT. The macroscopic, microscopic, and statistical analyses indicated that LT was as effective as antibiotic therapy in wound healing.

Keys for identification of third instar larva and adult blowflies of forensic importance

Blow flies are important bio-indicators in forensic investigations. Species identification is a key step in forensic entomology. This paper describes the morphological characters of adult flies and third instar larvae of Chrysomya megacephala, C. rufifacies and C. bezziana which are forensically important flies. This simplified key will enable easy identification of these flies which are commonly present in Chennai and are of importance in forensic investigation.

The Effect of Temperature Regimes and Tissue Types on The Development of Chrysomya megacephala Larvae (Diptera: callophoridae).

This study investigated the effects of three temperature regimes representing several specific development conditions of this blowfly: (25.7, 28.4and 30.6oC) and tissue types. Furthermore, Chrysomya megacephala colonies were reared on three different food sources (all rabbit carcasses, Liver and muscles) on the development of C.megacephala as important forensic fly, and their possible implications to calculate the postmortem interval (PMI). The results showed that the mean durations period from egg to adult eclosion of C. megacephala when reared on control rabbit at 25.7, 28.4 and 30.6 oC were 303.5, 217 and194.5 hrs, respectively. In addition, the mean duration period from egg to adult eclosion when the larvae reared on liver tissue at 25.7, 28.4and 30.6oC were 275.5, 205.5 and 188.5 hrs, respectively. Moreover, The Larvae of C.megacephala reared on muscle tissues from rabbit carcasses, the mean duration from egg to adult eclosion at 25.7oC 28.4oC, and 30.6oC were 293, 214.5 and 192.5 hrs, respectively. From the previous results, it is obvious that the mean duration in larvae reared on control rabbit carcasses was longer than those fed on muscle which longer than those reared on the liver at all temperature regimes.

Detection of Malathion in Different Stages of Chrysomaya megacephala and Its Implications for Forensic Entomology

This study investigated the potential effects of Malathion in rabbit carcasses on the developmental of Chrysomya megacephala larvea, an important forensic species, and their possible implications for the calculate the postmortm interval ( PMI) .Three domestic rabbits Oryctolagus cuniculus were used in each experiment. Two rabbits were administered orally with 513 mg/kg (R1), 1026 mg/kg (R2) of Malathion, The third one was fed with distilled water (R0).Chrysomya megacephala larvae were allowed to grow on the liver (L), muscles (M) and all carcasses of rabbit. Malathion was detected in all collected rabbit tissues that received different dosages of Malathion (R1 and R2) but not detected in any of the controls (R0).The highest Malathion concentration was detected in lungs followed by muscle tissue and fats of R2(35.7 mg/kg, 29.75 mg/kg, and 22.31mg/kg, respectively). All third larval instars and pupae of C. megacephala were positive for malathion (R1 and R2), while malathion was not detected in all samples from the control colony (R0). Strong correlations were found between administered dosage and tissue concentrations. Malathion concentrations were higher in the third larval instars sampled for the concentration (R2) than those from muscle tissues of (R2) which followed by those from L2 colonies. Detected Malathion concentrations in the third larval instars and pupae of C. megacephala were significantly lower than those detected in the rabbit tissues except fats and heart from postmortem interval rabbit tissues treated with (R1). Moreover, the highest levels of Malathion were noticed in the pupae emerged from (R2) colony. Whereas, the lowest levels were detected in the pupae emerged from M1 colony.

Preliminary observations of necrophagous dipteran activities and a new host record of parasitoids on a high-rise building

Abstract A preliminary study on the ecological activities of necrophagous Diptera on a highrise building in Malaysia was conducted from April to August 2010. Fresh chicken livers (approximately 500 g) serving as bait were placed on the rooftop (101.6 m from the ground). Three replicates were carried out, each replicate lasting 30 days with daily observations and fly sampling. Maggots found in the bait were collected at random: some were preserved in 70% ethanol while the others were reared to the adult stage. Results showed that the flies arrived on the bait between 8 hours and 3 days after placement. The oriental latrine blow fly Chrysomya megacephala (Diptera: Calliphoridae) was the first to reach this altitude, followed by the scuttle fly Megaselia scalaris (Diptera: Phoridae) and the flesh fly Liopygia ruficornis (Diptera: Sarcophagidae). The larvae of Chrysomya megacephala were first recovered from the bait. However, they were succeeded by sarcophagid larvae. The predominant sarcophagid larvae were then raised to the adult stage and the resulting adults were identified as Parasarcophaga dux. The other sarcophagid pupae were either parasitized by hymenopteran parasitoids or dead. We recorded two species of parasitoids emerging from Liopygia ruficornis pupae: Exoristobia philippinensis (Hymenoptera: Encyrtidae) and Dirhinus himalayanus (Hymenoptera: Chalcididae). Liopygia ruficornis is recorded as a new host for these parasitoids for the first time.

Disruption ofChrysomya megacephalaGrowth Caused by Lignan Grandisin : Table 1

The toxicity of tetrahydrofuran lignan grandisin was evaluated against larvae of Chrysomya megacephala F. (Diptera: Calliphoridae). The bioassay involved topical treatment on larvae, topical treatment on egg masses, and incorporation in the larval diet. Grandisin showed inhibition of postembryonic development by ovicidal (30%) and larvicidal (38%) effects and reduced larval weight (4 mg), when topically applied on egg masses and starving larvae (L1) at a concentration of 100 microg/microl. These findings elucidated the effect of grandisin on the C. megacephala life cycle and its potential to control C. megacephala populations.

Influence of photoperiod on body weight and depth of burrowing in larvae of Chrysomya megacephala (Fabricius) (Diptera, Calliphoridae) and implications for forensic entomology

Blowflies use discrete, ephemeral breeding sites for larval nutrition. After exhaustion of the food supply, the larvae disperse in search of sites to pupate or to seek other sources of food in a process known as post-feeding larval dispersal. In this study, some of the most important aspects of this process were investigated in larvae of the blowflies Chrysomya megacephala exposed to a variety of light: dark (LD) cycles (0:0 h, 12:12 h and 24:0 h) and incubated in tubes covered with vermiculite. For each pupa, the body weight and depth of burrowing were determined. Statistical tests were used to examine the relationship of depth of burrowing and body weight to photoperiod at which burrowing occurred. The study of burial behavior in post-feeding larval dispersing can be useful for estimating the postmortem interval (PMI) of human corpses in forensic medicine.

Larvicidal effects of mineral turpentine, low aromatic white spirits, aqueous extracts of Cassia alata, and aqueous extracts, ethanolic extracts and essential oil of betel leaf (Piper betle) on Chrysomya megacephala.

Many methods have been employed, with variable success, in the treatment of cutaneous myiasis caused by Chrysomya species. Experiment 1: to assess the larvicidal effect of mineral turpentine (MT) and the main ingredient of MT, low aromatic white spirits (LAWS), on Chrysomya megacephala larvae in vitro. Experiment 2: to assess the larvicidal effects of aqueous extracts of winged senna (Cassia alata), and aqueous extracts, ethanolic extracts and essential oil of betel leaf (Piper betle). In experiment 1, two samples of LAWS were obtained from two industrialists (samples 1 and 2). Adult flies of C. megacephala were bred in the insectory of the Department of Parasitology, Faculty of Medicine, University of Colombo. Petri dishes were prepared with pads of cotton wool. These cotton pads were soaked separately in MT, LAWS samples 1 and 2, and normal saline as a control. Ten larvae were placed in each Petri dish. The activity of the larvae was observed and recorded half-hourly. MT and the two samples of LAWS were analyzed by chromatography. In experiment 2, volatile essential oil of betel was prepared using a standard steam distillation process. An ethanolic extract of betel was obtained after boiling the crushed leaf with water, and mixing the stock with ethanol. Betel oil dilutions of 1-4% were prepared using 1% Tween 80 (v/v aq) as a solvent, with 0.05 g/100 mL sodium lauryl sulphate (as stabilizer) and 0.01 g/100 mL methyl paraben (as a preservative). Cotton wool swabs soaked in 1, 2, 3 and 4% essential oil of betel in 1% Tween 80 (v/v aq) prepared as above, 1, 2, 3 and 4% ethanolic extract of betel, 50 and 25% aqueous extract of C. alata, and 50 and 25% aqueous extract of betel were placed in separate Petri dishes. Ten larvae were placed in each Petri dish. 1% Tween 80 solvent with the stabilizer and the preservative, but without betel essential oil, was used as a negative control and MT was used as a positive control. Larval motility was assessed as before. MT and the two LAWS samples killed the larvae in vitro within 4 h. Chromatography showed more unidentified constituents in MT than in pure LAWS, indicating additional substances in MT. The 4 and 3% preparations of the essential oil of betel were effective in killing 100% of the larvae of Chrysomya within 3 h 30 min. The 2% extract of betel essential oil killed 96.7% of larvae in 4 h. Ethanolic and aqueous extracts of betel, the aqueous extract of C. alata, normal saline and the Tween 80 solvent were not larvicidal. MT and LAWS, the main ingredient of MT, were effective in killing Chrysomya larvae. Essential oil obtained from betel leaves also showed a dose-dependent larvicidal effect on Chrysomya larvae. This natural product may be effective in the treatment of wound myiasis.