Effect of Ointments of Sulphur or Pyrogenium on Larvae of Cochliomyia hominivorax (Diptera: Calliphoridae).

BACKGROUND: Myiasis by Cochliomyia hominivorax (Diptera: Calliphoridae) is a serious problem in animal health in tropical and sub-tropical regions. Ointment-type preparations are a good option of formulation in cases of myiasis in farm and pet animals. Sulphur and Pyrogenium have already shown in-vitro efficacy on C. hominivorax. This article describes an in-vitro experiment to test the inhibition of development from exposing larvae of C. hominivorax to two homeopathic ointments (prepared individually with Sulphur or Pyrogenium). METHODS: The homeopathic ointments were produced by mixing sterile lanolin, tocopherol and homeopathic medicine on a hydroalcoholic basis according to the Brazilian Homeopathic Pharmacopoeia. Larvae were obtained from naturally occurring myiases in sheep (wild larvae) or from a laboratory colony. The test consisted of exposing a group of 10 third-stage C. hominivorax wild larvae in contact with Sulphur or Pyrogenium ointment, or a group of 15 laboratory-propagated larvae in contact with the alcoholic vehicle of the ointment or homeopathic medicines prepared in sterile water (Sulphur or Pyrogenium), and observing the effect on the development, longevity and fertility of the blow-fly specimens. RESULTS: The C. hominivorax larval inhibition rate was 90.0% for the Sulphur ointment group and was 86.0% for the Pyrogenium ointment group. The non-alcoholic vehicle and the alcoholic vehicle inhibited the development of 24.0% and 22.08% of the larvae respectively. Sulphur prepared in sterile water inhibited the development of 74.67% and Pyrogenium in sterile water inhibited 73.33% of larvae. Specimens that survived contact with homeopathic ointments had their longevity decreased and did not reproduce. CONCLUSION: Ointments of Sulphur or Pyrogenium were able to inhibit the development of C. hominivorax larvae. The ointment vehicle was harmless.

Histological and Immunohistochemical Study of Wounds in Sheep Skin in Maggot Therapy by Using Protophormia terraenovae (Diptera: Calliphoridae) Larvae.

A study was performed to evaluate the implication of Protophormia terraenovae larvae as a surgical therapy for wounded skin. Three groups of sheep (n = 25) were considered based on larval doses. Groups 1 and 2 were artificially infested with low and high concentrations of L1 stage P. terraenovae, respectively, and group 0 served as a control. Skin biopsies were taken at 4 and 14 d postinfestation (D.P.If). A histopathological study was carried out to evaluate the lesions with a score, numbers of eosinophils and mast cells, and an immunohistochemical analysis of CD3, CD79α, and CD68 as T lymphocytes, B lymphosytes, and macrophages, respectively. The results indicated that higher larval doses led to faster regeneration by 14 D.P.If. Furthermore, the higher larval doses showed a high number of the CD68 marker and eosinophils and a low number of CD3 and CD79α markers and mast cells. In addition, the number of mast cells, T lymphocytes, and macrophage markers increased when the lesion progressed; however, a low number of immunolabeled CD79α cells and eosinophils were observed. The results indicate a possible positive effect of larvae in the healing of certain wounds.

A formulation of neem and hypericum oily extract for the treatment of the wound myiasis by Wohlfahrtia magnifica in domestic animals.

Untreated, traumatic, or wound myiases can cause severe consequences to animal health and welfare as well as economic losses to livestock productions. For healing myiasis-caused wounds, disinfectant such as creolin is wrongly but currently used in association with insecticides. Though effective, creolin is highly toxic to the patients, is inadequate with respect to the repellent effect, and may delay the healing of treated wounds. In this uncontrolled study, the efficacy of the patented plant-derived formulation 1 Primary Wound Dressing© (1-PWD), composed of neem oil (Azadirachta indica A. Juss.) and the oily extract of Hypericum perforatum (L.) flowers, has been investigated. Forty-four domestic animals of different species suffering from wound myiasis lasting for up to 25 days, at different parts of the body, were enrolled in the study. No systemic or local antibiotic or disinfectants' treatment was administered. Larvae recovered on open wounds and adults reared from mature larvae were identified as Wohlfahrtia magnifica. All the treated wounds healed in a range of 10 to 32 days without further infestation. None of the recruited animals presented bacterial complications. Data herein presented indicate that the tested natural plant-derived formulation is able to manage the infestation caused by W. magnifica larvae and the healing process of traumatic infested wounds in several domestic animal species, without any side effect on the living tissue and without the need to use local or systemic chemical or other products.

Toxicity and oviposition deterrence of essential oils of Clinopodium nubigenum and Lavandula angustifolia against the myiasis-inducing blowfly Lucilia sericata.

Cutaneous myiasis is a severe worldwide medical and veterinary issue. In this trial the essential oil (EO) of the Andean medicinal plant species Clinopodium nubigenum (Kunth) Kuntze was evaluated for its bioactivity against the myiasis-inducing blowfly Lucilia sericata (Meigen) (Diptera Calliphoridae) and compared with that of the well-known medicinal plant species Lavandula angustifolia Mill. The EOs were analysed and tested in laboratory for their oviposition deterrence and toxicity against L. sericata adults. The physiology of EO toxicity was evaluated by enzymatic inhibition tests. The antibacterial and antifungal properties of the EOs were tested as well. At 0.8 µL cm-2, both EOs completely deterred L. sericata oviposition up to 3 hours. After 24 h, the oviposition deterrence was still 82.7% for L. angustifolia and the 89.5% for C. nubigenum. The two EOs were also toxic to eggs and adults of L. sericata. By contact/fumigation, the EOs, the LC50 values against the eggs were 0.07 and 0.48 µL cm-2 while, by topical application on the adults, LD50 values were 0.278 and 0.393 µL per individual for C. nubigenum and L. angustifolia EOs, respectively. Inhibition of acetylcholine esterase of L. sericata by EOs (IC50 = 67.450 and 79.495 mg L-1 for C. nubigenum and L. angustifolia, respectively) suggested that the neural sites are targets of the EO toxicity. Finally, the observed antibacterial and antifungal properties of C. nubigenum and L. angustifolia EOs suggest that they could also help prevent secondary infections.

An acetone extract of Clausena anisata may be a potential control agent for flies encountered in cutaneous myiasis.

Clausena anisata is a medicinal plant used traditionally to treat myiasis and as an insect repellent by various communities. We have previously demonstrated the effects of C. anisata extracts on blowfly feeding and development in our laboratory. The impact of C. anisata leaf extracts on populations of different fly species on farms in Mpumalanga, South Africa was investigated in this study under field conditions. Flies were exposed to liver baits treated with acetone leaf extracts of C. anisata (150 mg/mL). Fly numbers and composition on two farms, with and without C. anisata treated liver, were compared during a period of 12 weeks when fly populations were expected to be high. Observations were made on fly behaviour and development, adult sizes and numbers. The flies exposed to liver treated with the leaf extract of C. anisata had a decreased rate of development, prolonged larval period, smaller body sizes and more sluggish behaviour compared to those subjected to the control treatment. No significant differences were, however, found between the numbers and sizes of flies on the treated and on the control farm, which was most likely due to the limited nature of the baiting programme we followed. The effects of C. anisata extracts on blowfly behaviour and development observed in previous laboratory studies were confirmed in this field evaluation. Although the extracts did not have a significant effect on the overall population size in this experiment, we believe that the C. anisata leaf extract could be useful in integrated pest management based on its effect on larval development. In addition, species such as Lucilia cuprina and Chrysomya marginalis seemed to have been repelled by the C. anisata treated liver; as a result, further work should explore this aspect and how it can be used for the protection of animals.

In vitro and in vivo effects of neem tree (Azadirachta indica A. Juss) products on larvae of the sheep nose bot fly (Oestrus ovis L. Díptera: Oestridae).

Two studies were carried out in order to test the effects of neem tree extracts (Azadirachta indica A. Juss) on sheep bot fly larvae (Oestrus ovis L. Diptera: Oestridae). First, aqueous extracts from neem seeds (ASNE) at 0, 5 y 10% (w/v) concentrations were tested on larval mortality in vitro. In a second study, the effect of oral administration with neem seed meal (0, 100 y 200mg/kg) and neem leaves (1% of diet) on number of larvae found at necropsy and larval development was evaluated in experimentally O. ovis-infected sheep. Results in Experiment 1 showed a significant (P<0.05) effect of ASNE on time to L1 mortality in a dosis-dependent manner. In Experiment 2, oral administration of seeds or leaves did not affect the number of larvae found at necropsy of the sheep, but interfered with larval development and there was a tendency to reduce larval weight at the end of the infection period (55d).

Bioactivities of some essential oils against the camel nasal botfly, Cephalopina titillator.

Nasopharyngeal myiasis of camels is caused by the larvae of Cephalopina titillator. We determined the efficacy of essential oils (EOs) of pumpkin, Cucurbita maxima; lupinus, Lupinus luteus; garlic oil, Allium sativum; and peppermint, Mentha piperita, against the third larval stage of C. titillator using larval immersion tests. The positive control group was treated with ivermectin and the negative control one was treated with distilled water and few drops of Tween 80. Larvae were reared until adult emergence. The data indicated that complete larval mortalities were reached 24 h post treatment (PT) with 2 % pumpkin, 7.5 % garlic and peppermint, 30 % lupinus, and 0.15 % ivermectin. The lethal values, LC50s, were 0.20, 0.44, 0.42, 0.47, and 0.03 %, respectively. Pumpkin and ivermectin were 2 and 17 times, respectively, more effective than the other EOs. Ivermectin was seven times more intoxicating than pumpkin oil. Formation of pupae had been stopped after treatment of larvae with 2 % pumpkin, 7.5 % garlic and peppermint, 30 % lupines, and 0.04 % ivermectin. Adult emergence had been completely ceased following treatment of larvae with 0.5 % EOs and 0.04 % ivermectin. Morphological abnormalities were pronounced after treatments, and peppermint oil was the foremost cause of deformation in larvae (44 % PT with 7.5 %) and pupae (40 % PT with 2 %). Pumpkin oil (6 %) was selected to be the drug of choice for controlling C. titillator. Besides their insecticidal effects, EOs are much safer than ivermectin regarding health and environmental issues. Consequently, EOs described herein merit further study as potential nasal drench for C. titillator control.

Isolation of seselin from Clausena anisata (Rutaceae) leaves and its effects on the feeding and development of Lucilia cuprina larvae may explain its use in ethnoveterinary medicine.

ETHNOPHARMACOLOGICAL RELEVANCE: The leaves of Clausena anisata are used traditionally to expel maggots from wounds of animals in Zimbabwe. We have previously proved in the laboratory that the plant certainly affects the behaviour and growth of blowfly larvae. The objective of this study was to isolate and identify the active compounds responsible for this activity. MATERIALS AND METHODS: The acetone extract of Clausena anisata leaf powder was separated by solvent-solvent partition into five fractions. The n-hexane fraction was the most active in the larvicidal assay and therefore subjected to open column chromatography on silica gel. RESULTS: The isolated compound was identified by nuclear magnetic resonance (NMR) and mass spectroscopy (MS) as the pyranocoumarin, seselin, chemically known as 2',2'-dimethylpyranocoumarin. It inhibited feed intake in the first and second instars of blowfly larvae at the minimum concentration tested of 1 ppm resulting in significant lower mass pupae (13.5±0.5 mg and 22.4±0.4 mg for the first and second instar larvae respectively) compared to the solvent control group (26.19±0.8 mg) (p<0.05). CONCLUSIONS: This is the first report of the isolation of seselin from the leaves of Clausena anisata and the first report of the compound having an effect against blowfly larvae.

Lousicidal, ovicidal and repellent efficacy of some essential oils against lice and flies infesting water buffaloes in Egypt.

The lousicidal and repellent effects of five essential oils were investigated for the first time against the buffalo louse, Haematopinus tuberculatus, and flies infesting water buffaloes in Qalyubia Governorate, Egypt. For the in vitro studies, filter paper contact bioassays were used to test the oils and their lethal activities were compared with that of d-phenothrin. Four minutes post-treatment, the median lethal concentration, LC50, values were 2.74, 7.28, 12.35, 18.67 and 22.79% for camphor (Cinnamomum camphora), onion (Allium cepa), peppermint (Mentha piperita), chamomile (Matricaria chamomilla) and rosemary oils (Rosmarinus officinalis), respectively, whereas for d-phenothrin, it was 1.17%. The lethal time (50) (LT50) values were 0.89, 2.75, 15.39, 21.32, 11.60 and 1.94 min after treatment with 7.5% camphor, onion, peppermint, chamomile, rosemary and d-phenothrin, respectively. All the materials used except rosemary, which was not applied, were ovicidal to the eggs of H. tuberculatus. Despite the results of the in vitro assays, the in vivo treatments revealed that the pediculicidal activity was more pronounced with oils. All treated lice were killed after 0.5-2 min, whereas with d-phenothrin, 100% mortality was reached only after 120 min. The number of lice infesting buffaloes was significantly reduced 3, 6, 4, 6 and 9 days after treatment with camphor, peppermint, chamomile, onion, and d-phenothrin, respectively. Moreover, the oils and d-phenothrin significantly repelled flies, Musca domestica, Stomoxys calcitrans, Haematobia irritans and Hippobosca equina, for 6 and 3 days post-treatment, respectively. No adverse effects were noted on either animals or pour-on operators after exposure to the applied materials. Consequently, some Egyptian essential oils show potential for the development of new, speedy and safe lousicides and insect repellents for controlling lice and flies which infest water buffaloes.

Traditional remedies used for the treatment of cattle wounds and myiasis in Amatola Basin, Eastern Cape Province, South Africa.

A questionnaire survey was carried out to document traditional remedies used in the treatment of cattle wounds and myiasis in Amatola Basin. Eighty-three cattle farmers from nine villages were interviewed. The majority of respondents (67.9%) use traditional remedies for treatment of these conditions. However, 25.9% of them use a combination of traditional remedies with conventional medicines. The survey revealed that 13 medicinal plants belonging to 11 families were used. Aloe ferox, Prunus persica and Phytolacca heptandra were, however, the most commonly used. Leaves are the most frequently used plant part, often prepared as an infusion. Other non-plant remedies used include disinfectants, antiseptics as well as diesel and petrol. Manual removal of maggots from wounds was also practise and treatment is usually continued until the wound heals.

Persistence of human myiasis by Oestrus ovis L. (Diptera: Oestridae) among shepherds of the Etnean area (Sicily) for over 150 years.

From a study carried out in 22 townships of the Etnean area, by interviewing 112 shepherds, it was confirmed that 90 of them (80.3%), once or more in their lives, had contracted myiasis by Oestrus ovis L., habitual agent of estriasis in sheep. The most frequent sites of involvement were the pharynx (77 times), often extending to the larynx, the conjunctiva (56), followed by the nose (32) and rarely the ear (1). Multiple simultaneous sites involvement was also frequent affecting 54.4% of the shepherds. The chief symptom was pain, sometimes accompanied by fever and malaise. The shepherds go rarely to see a doctor (only 7 out of 90), the greater part preferring traditional remedies. It is curious to note that myiasis associated with Oe. ovis was already observed more than 150 years ago by a Sicilian physician, G. A. Galvagni, who had pointed out the high incidence of the myiasis in shepherds in the area. The persistence of human myiasis in the Etnean area appears to be related to the fact that in this region the conditions of sheep farming and the lifestyle of shepherds have not changed so much since then.

The effect of a drying agent (B26) on wool moisture and blowfly strike.

A drying agent (B26) was applied as a mist to sheep fleece. A reduction of 30 per cent in wool moisture was recorded, which persisted for 10 to 12 weeks. Reapplication of B26 extended the period of dryness, without adding to the reduction of moisture. Treatment using 100 to 200 ml of the drying agent resulted in reduced fleece moisture content for seven days when exposed to wetting by simulated rain. Treated sheep showed a 60 per cent reduction in the number and severity of fleece rot lesions. Diazinon reduced the incidence of natural flystrike by 50 per cent and the drying agent by 75 per cent over a five week period before shearing compared with untreated animals.