Larvicidal and adulticidal effects and ultrastructural changes of larvae midgut epithelium of musca domestica (diptera: muscidae) fed with bacillus thuringiensis var. kyushuensis

Abstract INTRODUCTION: Musca domestica is resistant to many insecticides; hence, biological control is a suitable alternative. METHODS: We evaluated the lethality of strain Btk176 towards the larval and adult M. domestica and the histopathological effects in the larvae midgut. RESULTS: We observed 99% larval and 78.9% adult mortality within 48 hours of spore ingestion (dosage, 2.4×108 CFU/ml). The histopathological effects were consistent with cytotoxicity. PCR analysis showed the presence of the cry1Ba gene. Transmission electron microscopy revealed a bipyramidal parasporal body. Thurigiensin activity was not detected. CONCLUSIONS: The serovar, Btk176 might be a potential biocontrol agent for houseflies.

Chemical composition and insecticidal activity of Cymbopogon citratus essential oil from Cuba and Brazil against housefly / Composição química e atividade inseticida do óleo essencial de Cymbopogon citratus de Brasil e Cuba contra mosca doméstica

Essential oil of Cymbopogon citratus collected from Brazil and Cuba was tested to a chemical characterization and then was tested on the post-embryonic development of Musca domestica. The chemical composition analysis by GC-MS of the oils from Brazil/Cuba allowed the identification of 13 and 12 major constituents respectively; nine of them common to both. In the both oils, the main components were the isomers geranial and neral, which together form the compound citral. This corresponds to a total of 97.92%/Brazil and 97.69%/Cuba of the compounds identified. The monoterpene myrcene, observed only in the sample of Cuba, presented a large relative abundance (6.52%). The essential oil of C. citratus (Brazil/Cuba) was dissolved in DMSO and tested at concentrations of 5, 10, 25, 50, 75 and 100% and citral was prepared by mixing 16.8 mg with 960 µL DMSO. Both essential oils and monoterpene citral were applied topically to newly-hatched larvae (1µL/larva). The results showed a lethal concentration (LC50) of 4.25 and 3.24% for the Brazilian and Cuban essential oils, respectively. Mortalities of larval and newly-hatched larvae to adult periods were dose-dependent for the two both oils as for monoterpene citral, reaching 90%. Both essential oils and citral caused morphological changes in adult specimens.

O óleo essencial de Cymbopogon citratus, coletado no Brasil e em Cuba, foi caracterizado quimicamente e testado no desenvolvimento pós-embrionário de Musca domestica. A análise da composição química dos óleos essenciais (Brasil/Cuba), por Cromatografia Gasosa acoplada ao espectrômetro de massa (GC-EM), permitiu a identificação de 13 e 12 componentes principais, respectivamente; nove deles comuns aos dois. Em ambos os óleos, os principais componentes foram os isômeros geranial e neral, que, juntos, formam o composto citral. Esse corresponde a um total de 97,92%/Brasil e 97,69%/Cuba dos compostos identificados. O monoterpeno mirceno, observado na amostra cubana, apresentou grande abundância relativa (6,52%). O óleo de C. citratus (Brasil/Cuba) foi dissolvido em DMSO, obtendo–se as concentrações de 5, 10, 25, 75 e 100%; e o citral (16,8 mg) foi misturando com 960mL de DMSO. Tanto o óleo essencial como o monoterpeno citral foram aplicados topicamente nas neolarvas (1µL/larva). Os resultados mostraram uma concentração letal (CL50) de 4,25% e 3,24% para o óleo essencial brasileiro e cubano, respectivamente. As mortalidades do período larval e o de neo-larva a adulto foram dose-dependentes, tanto para os óleos como para o monoterpeno citral, podendo chegar a 90%. Ambos os óleos essenciais e citral causaram alterações morfológicas nos espécimes adultos.

Side effects of IGR cyromazine on nasonia vitripennis [hymenoptera: pteromalidae] a parasitic wasp of house fly pupae

Combination of cyromazine as an Insect Growth Regulator [IGR] and Nasonia vitripennis [Hymenoptera: Pteromalidae] a parasitic wasp may be an effective tool for reducing the house-fly populations in poultry houses and livestock farms. This study was conducted to assess the side effects of the IGR cyromazine on the level of parasitism and numbers and the longevity of emerged N. vitripennis parasitoids from house fly pupae. Cyromazine treated cloth target was used as the contaminating method of the parasitoids which was applied in this research study. The Weibull distribution showed that there was no significant difference among controls and cyromazine treated targets for longevity data. There was no significant effect of cyromazine on the level of parasitism of N. vitripennis using ?2 test. One-way ANOVA showed that the actual numbers emerging were significantly higher in the control than in two cyromazine treatments; however, it is a useful phenomenon because of reducing the hyperparasitism. There is a good consistency between using N. vitripennis and 1.1% or 0.9% cyromazine treated targets. Therefore cyromazine treated targets can be applied as a safe delivery vehicle for applying the cyromazine IGR in the poultry houses and livestock farms in an Integrated Pest Management [IPM] program

Effect of triflumuron and pyriproxyfen on Musca domestica L. larval stages in the laboratory

The residual effect of triflumuron and pyriproxyfen on Musca domestica L larval stages was studied in the laboratory. Both IGRs at varying concentrations ranging between 0.5 to 2.5 mg/L were placed inside beakers with mice chow and vitamin B complex and water as food for the 1st, 2nd and 3rd instars M.domestica larvae. Both IGRs inhibit M. domestica adult emergence of 98-98.5% when applied at the lowest concentration of 0.5 mg/L on the 1st instar, 93-97% of adult emergence inhibition on the 2nd instar, and 91-97% of adult emergence inhibition on the 3rd instar larvae respectively. There was no significant difference between triflumuron and pyriproxyfen on housefly adult emergence inhibition when fed to the 1st, 2nd and 3rd instars M.domestica larvae [P> 0.05]. However, there was a significant difference between the IGRs and the control [P< 0.05]. Both triflumuron and pyriproxyfen are effective in inhibiting adult emergence of housefly M domestica and therefore should be recommended for fly control particularly in chicken farms and dumping grounds in Malaysia for housefly control activities

Developmental inhibition and reproductive potential impairment in Musca domestica L. by heavy metals.

Post embryonic development and adult emergence of housefly, M. domestica L. was adversely affected in varying degrees on exposure of larvae to 6 different heavy metals. Of these, salts of mercury, aluminium and cadmium exhibited significant reduction in normal adult emergence. High decline in reproductive potential in terms of female fecundity and egg hatchability was also observed in the F1 progenies of treated larvae. The results are discussed in light of heavy pollution of environment by such contaminants.

Resistance of musca domestica [L.] [diptera: muscidae] from gamasa city to some insecticides

Susceptibility tests for house fly Musca domestica collected from Gamasa City and laboratory bred 1 were carried out. The data suggested that the levels of resistance in Gamasa population against malathion, diazinon, dimethoate [organophosphorus compounds] and permethrin [pyrethroid 1] were developed, while deltamethrin and cypermethrin were still effective. The highest homogeneity response was for malathion, followed by dimethoate, deltamethrin and cypermethrin. On the other hand, the highest homogeneity response in laboratory population was that of cypermethrin and deltamethrin followed by malathion, dimethoate, permethrin and then diazinon. The EST activity was higher in laboratory population [3 heavy bands], than Gamasa one [2 faint bands], while the activity of LDH and G-6PDH were higher in Gamasa population than in laboratory one. The ADH activity was the same in both populations. This means that EST was not the main detoxifying target in Musca domestica

Change in nucleic acids [RNA and DNA] contents, of Musca Domestica, under the effects of neem compounds and DDVP

Nucleic acids [RNA and DNA] contents were estimated in Musca domestica [PCSIR strain] after LD50 treatment of nem compounds [i. e. Margosan [OTM], H - 34, N6 - b] and an organophosphate [DDVP]. RNA and DNA contents were inhibited by all the undertest compounds. Treatment with Margosan - [OTM], H -34 and N6 - b resulted in the inhibition of RNA content upto 23.37%, 23.55% and 33.32% respectively. Whereas the organophosphate, DDVP decreased the RNA content upto 9.67% The effectiveness of the compounds for inhibiting RNA contents may be summarized as follows DDVP < Margosan - O[TM] < H -34 < N6-b. DNA contents also decreased by all the compounds. Inhibition was 19.49% by Margosan - OTM 35.52% by H - 34; 25.02% by N - 6 - b, and 28.82% by DDVP. The effectiveness of the compounds for inhibiting DNA contents may be summarized as follows. Margosan- O[TM]

Effect of plumbagin on gonadotrophic cycle of the housefly, Musca domestica L.

Topical treatment of the phytochemical plumbagin in doses ranging 0.005-5 micrograms prevented oocyte development and affected fecundity and fertility in M. domestica. The treatment to wandering larvae was less effective as the compound could only effect the fertility to a significant level whereas the fecundity was not significantly reduced. The effect of the compound was more pronounced in adult treatments where both fecundity and fertility reduced drastically. The compound also effected the oocyte maturation as it arrested the development of vitellogenic oocyte at stage six. As the juvenile hormone analogue methoprene and moulting hormone 20-hydroxyecdysone or the mixture of these hormones could not restore the development of the oocyte in ovaries of plumbagin treated flies, it is concluded that the compound does not effect the female houseflies through hormonal pathways, instead in all probability it acts like a cytotoxic compound.