Characterization of intrapuparial development of Musca domestica (Diptera: Muscidae), under different temperatures in laboratory conditions.

Musca domestica (Linnaeus, 1758) (Diptera: Muscidae), popularly known as "housefly", is a highly synanthropic species, with economic, medical-sanitary, veterinary, and forensic importance. It is able to cause damage to health, transmit pathogenic agents, cause infection in domestic animals, and, in its immature stage, cause secondary myiasis. The scavenging habit of its immature stages makes these flies pioneers in colonizing both human and animal carcasses, from the initial stages of corpse decomposition to the final stages. Intrapuparial development studies of all stages of the biological cycle of these insects help estimate pupal age, being useful to forensic entomology to aid in determining the minimum postmortem interval (minPMI). This study describes, morphologically, the external structures of the pupae, under temperatures of 23, 27, and 30 ±â€…1 °C aiming to identify the characteristics that define their developmental stages and estimation of the pupae age of M. domestica. The whole experiment was carried out under laboratory conditions, with relative humidity 60 ±â€…10% and 12 hours of photoperiod. The process of pupariation and pupation including pre-pupae phases were observed; larvae pupae apolysis; early cryptocephalic pupae; late cryptocephalic pupae; phanerocephalic pupae; pharate adult, discriminated by eye color (transparent eyes, pink eyes, and red eyes); and the emergency of adults, which occurred in the intervals of 162-180; 138-144, and 96-102 hr, respectively, being described throughout the metamorphosis of the external morphological characteristics of the pupal stage of M. domestica.

Larvicidal and Adulticidal Activity of Essential Oils from Four Cuban Plants against Three Mosquito Vector Species.

Mosquitoes are one of the main vectors of many important diseases and their degree of resistance to chemical insecticides has increased. Nowadays, it has become crucial to identify novel plant larvicides with an eco-friendly impact. The components of essential oils from Croton linearis Jacq. (EO-Cl), Lantana involucrata L. (EO-Li), Ocimum sanctum var. cubensis M. Gómez. (EO-Os), and Zanthoxylum pistaciifolium Griseb. (syn. Zanthoxylum flavum subsp. pistaciifolium (Griseb.) Reynel (EO-Zp) were determined using gas chromatography-mass spectrometry (GC-MS) analysis. Larvicidal and adulticidal bioassays against Aedes aegypti, Anopheles albitarsis and Culex quinquefasciatus, were performed according to the World Health Organization standard methods. A high diversity of compounds was identified in the four oils, with a total of 152 compounds (33-70 components). EO-Cl, EO-Li, and EO-Os were classified as active against both insect forms, larvae and adults. Lantana involucrata showed the best results, with LC50 values from 33.8 to 41.7 mg/L. In most of the cases, it was not possible to associate the main compounds with the measured activity, supporting the hypothesis about probable synergistic interactions among major and minor compounds. The results indicate EO-Cl, EO-Os, and EO-Li as good eco-friendly insecticides with potential.

Development and Intrapuparial Characterization of Hydrotaea aenescens (Diptera: Muscidae) Raised at Different Temperatures Under Laboratory Conditions.

Species belonging to the Muscidae family are important in the medical-sanitary and forensic fields due to their biology. The intrapuparial stage of Hydrotaea aenescens (Wiedemann, 1830), which represents about 50% of the immature development cycle in muscoid Diptera, has not yet been studied in detail. This study identifies and describes the main temporal morphological changes that occur in the pupal body of H. aenescens during its development at 22, 27, and 32 ± 1°C, RH 60 ± 10% with a 12-hr photoperiod. Ten pupae were collected, sacrificed, and fixed every 3 hr after pupariation up to 24 hr, and every 6 hr thereafter until the first emergence. Emergence took place at 282, 174, and 126 hr at 22, 27, and 32°C, with 520, 340, and 260 pupae, respectively. External morphology was described and recorded at eight development stages: pupariation, pre-pupae, early and late cryptocephalic pupae, phanerocephalic pupae, pupae-adult apolysis, pharate adults, and imago, employing 18 key morphological characters for pupae age. These morphological pupae characters, comprise, therefore an alternative and/or additional method to aid in determining the minimum Postmortem Interval (minPMI).

Ultrastructure of the Immature Stages of Musca domestica (Diptera: Muscidae: Muscinae).

Musca domestica (Linnaeus, 1758) is a muscoid species that is widespread throughout the world and acts as a mechanical vector of different enteropathogens primarily in underdeveloped countries. The adult and its immature forms are associated with decaying organic matter and can be seen visiting human corpses and animal carcass, and the larvae can also cause an infestation on human and animal wounds, feeding on the tissues. These characteristics make them have a forensic significance and, mainly, a great sanitary importance. This study aimed to analyze and describe morphological aspects of their immature stages of M. domestica, including the eggs, the first-, second-, and third-instar larvae, and the puparium using scanning electron microscopy (SEM). The eggs have standard format that all muscoid flies shared. The exochorion has some modified cells that were used for embryonic respiration. The first-instar larvae present two openings on the posterior spiracle as in the second-instar larvae, but with the last one, we can observe the anterior spiracle structure. The third-instar larvae, as in some other Muscidae species, have a posterior spiracular opening with a sinuous form that is located near the edge of the spiracular plate. The puparium morphology is equal to the third instar with a respiratory structure that helps the breathing during the metamorphosis process. This article supports the need for knowledge over the morphological characteristics of the immature forms of the muscoid Diptera (Linnaeus, 1758) at the same time helping with the correct identification of this insect phase.

Larvicidal and adulticidal effects and ultrastructural changes of larvae midgut epithelium of Musca domestica (Diptera: Muscidae) fed with Bacillus thuringiensis var. kyushuensis.

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.

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.

Ultrastructure of immature stages of the black dump fly: Ophyra aenescens (Wiedemann, 1830) (Diptera: Muscidae: Azeliinae).

Ophyra aenescens (black dump fly) originally belonged to the New World, however, now it is spread worldwide. This fly is a mechanical vector of some pathogenic microorganisms and eggs of the human botfly (Dermatobia hominis). The adults are associated with decaying matter and the immature stages colonize animal and human corpses. It is considered an important muscid species for forensic entomology. The aim of this study was to describe the morphology of the eggs, the three larval instars and the puparia of O. aenescens using scanning electron microscopy (SEM). The spiracular opening of the first instar has an interruption in the middle of its length. Comparing to the other instar, the ventral tubercles are only developed in the first instar. The anterior spiracles have a variation in the numbers of spiracular ramification. The puparia morphology is similar to the third instar larvae, however the cephalic region is retracted and on the third thoracic segment, a respiratory structure is present. In conclusion, the SEM technique used and the results obtained are helpful to describe and differentiate the immature stages of O. aenescens and consequently support forensic and medical entomology.

Effect of age on cuticular hydrocarbon profiles in adult Chrysomya putoria (Diptera: Calliphoridae).

A species-specific complex mixture of highly stable cuticular hydrocarbons (CHCs) covers the external surface of all insects. Components can be readily analyzed by gas chromatography coupled to mass spectrometry (GC-MS) to obtain a cuticular hydrocarbon profile, which may be used as an additional tool for the taxonomic differentiation of insect species and also for the determination of the age and sex of adult and immature forms. We used GC-MS to identify and quantify the CHCs of female and male Chrysomya putoria (Wiedemann, 1818) (Diptera: Calliphoridae) from one to five days old. CHCs ranged from C21 to C35 for females and from C21 to C37 in males. Major compounds were the same for both sexes and were 2-MeC28, C29:1, n-C29, 15-,13-MeC29, 2-MeC30, C31:1, n-C31 and 15-,13-MeC31. The relative abundance of each component, however, varied with age. Cluster Analysis using Bray-Curtis measure for abundance showed that cuticular hydrocarbon profiles are a strong and useful tool for the determination of age in adult C. putoria.

Bionomy of two flies of sanitary and forensic importance: Peckia (Sarcodexia) lambens (Wiedemann) and Oxysarcodexia amorosa (Schiner) (Diptera, Sarcophagidae)

ABSTRACTThis study aims to elucidate the bionomy of Peckia(Sarcodexia) lambens and Oxysarcodexia amorosa to provide data for medical, veterinary and forensic entomology analyses. We analyzed larval stage duration (L1–L3), weight of the mature larvae (L3), pupal stage duration, L1–adult duration, adult emergence and viability of larvae and adults of both species. Larval viability of P. (S.) lambens was 82% and the mean duration of the larval stage was 3.51 ± 0.99 days. The mature larvae had a mean weight of 33.67 ± 7.13 mg. The mean duration of the pupal stage was 8.26 ± 0.93 days and the mean duration of the L1–adult was 11.53 ± 1.22 days. Mean lifespan for females and males was 39.33 ± 1.52 and 57.33 ± 4.72 days, respectively. Larval viability of O. amorosa was 76% and mean duration of larval stage was 3.51 ± 0.64 days. Mature larvae had a mean weight of 28.28 ± 3.38 mg. Mean duration of the pupal stage was 10.14 ± 0.63 days and mean duration of the L1–adult was 13.60 ± 0.69 days. Mean lifespan for females and males was 83.66 ± 15.94 and 84.00 ± 19.97 days, respectively. Oxysarcodexia amorosa showed a L1–adult stage longer than P. (S.) lambens; however both species showed low viability. O. amorosa laid more larvae than P. (S.) lambens, this fact may occur because O. amorosa had longer life duration.

Preliminary screening of the larvicidal effect of Brevibacillus laterosporus strains against the blowfly Chrysomya megacephala (Fabricius, 1794) (Diptera: Calliphoridae).

INTRODUCTION: This study evaluated whether different strains of Brevibacillus laterosporus could be used to control larvae of the blowfly Chrysomya megacephala, a pest that affects both human and animal health. METHODS: Mortality rates were recorded after 1-mL suspensions of sporulated cells of 14 different strains of B. laterosporus were added to 2.5g of premixed diet consisting of rotting ground beef fed to first instar larvae of C. megacephala. All bioassays were performed using 10 larvae per strain, with a minimum of three replicates for each bioassay. Larval mortality was recorded daily up to seven days. RESULTS: Strains Bon 707, IGM 16-92, and Shi 3 showed the highest toxicity toward the larvae producing 70.5%, 64.5%, and 51.6% of larval mortality, respectively, which was significantly higher than that in the control group (p < 0.05). In contrast, strains NRS 1642, NRS 661, NRS 590 BL 856, NRS 342, ATCC 6457, Bon 712, and NRS 1247 showed limited or no pathogenic activity against the target larvae. CONCLUSIONS: Our preliminary data indicated that B. laterosporus could be used to develop bioinsecticides against C. megacephala.

Preliminary screening of the larvicidal effect of Brevibacillus laterosporus strains against the blowfly Chrysomya megacephala(Fabricius, 1794) (Diptera: Calliphoridae)

: This study evaluated whether different strains of Brevibacillus laterosporus could be used to control larvae of the blowfly Chrysomya megacephala , a pest that affects both human and animal health.

Chemical composition and insecticidal activity of Cymbopogon citratus essential oil from Cuba and Brazil against housefly.

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.

Detection and preliminary physico-chemical properties of antimicrobial components in the native excretions/secretions of three species of Chrysomya (Diptera, Calliphoridae) in Brazil.

Antibiotic-resistant bacteria in hospitals and communities increasingly threaten public health in Brazil and the rest of the World. There is an urgent need for additional antimicrobial drugs. Calliphorid blowfly larvae are a rich source of antimicrobial factors but the potential of Neotropical species has been neglected. This preliminary study evaluates the antimicrobial activity of the native excretions/secretions of larvae of three species of Brazilian calliphorids, Chrysomya megacephala, Chrysomya albiceps and Chrysomya putoria. Native excretions/secretions were collected from third instar larvae, sterile filtered and tested for antibacterial activity against Staphylococcus aureus 9518, Escherichia coli K12 4401 and Serratia marcescens 365. Turbidometric assays were made in micro-plates, using an ELISA reader, with readings taken up to 22 h. Bacterial suspensions at the start and end of each experiment were also serially diluted, spread on nutrient agar plates and then colony forming units counted. The physico-chemical characteristics of the native excretions/secretions were also tested by freezing/thawing, boiling, and protease digestion. The native excretions/secretions of larvae from these three Chrysomya species significantly inhibited bacterial growth. Therefore, Brazilian calliphorid flies could potentially provide new classes of antibiotics.

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.

Ultrastructural studies of some character of Diptera (Muscidae) of forensically importance.

Insects are important in the decomposition of cadavers. In the field of forensic entomology, the taxonomic identification is essential to proceed to any procedure. The use of these insects in medico criminal investigation is the object of forensic entomological studies; the flies are generally attracted to cadavers and one of the most important contributions is to estimate the postmortem interval. The scanning electron microscopy, which allows rapid and accurate identification of character could be used to help identify different species of forensics flies, has been highlighted as it allows better visualization of the external morphology of immature and some adults. The aim of this study was to describe the katepisternals in females of Morellia humeralis and Biopyrellia bipuncta; the ommatidia of the compounds eyes of the male of B. bipuncta; the antennae of females of Ophyra aenescens and Ophyra albuquerquei and the ocellar triangle of the last two species and O. chalcogaster examined by scanning electron microscopy to help increase the anatomical database on flies for forensic importance. The katepisternals of M. humeralis and B. bipuncta were densely covered by different groups of sensilla. The surface of the ocellar region of O. aenescens was not covered by sensilla, but in O. albuquerquei and O. chalcogaster were densely covered by different types of sensilla. The coeloconic sensilla were only found in the flagellum of O. albuquerquei.

Ultrastructure of immature stages of Lucilia cuprina (Diptera: Calliphoridae) using scanning electron microscopy.

The blowfly Lucilia cuprina is distributed worldwide and is a mechanical vector of pathogens. It can cause myiasis in humans and is strongly related to forensic entomology, as it is frequently found on human and animal corpses. However, most of the L. cuprina found on corpses are the immature stages of this fly. Correct identification is very important for forensic entomology but at present only the identification keys of adult L. cuprina are available. Thus, the aim of this paper was to describe and analyze the morphological characteristics of all larval instars and the puparia of L. cuprina using scanning electron microscopy (SEM).

First record of acari Arrenurus Dugès, 1834 as a parasite of Odonata species in Brazil

Water mites are common and widespread parasites of some aquatic insects in freshwater habitats. This is the first record of acari Arrenurus Dugès, 1834, as a parasite of Odonata in Brazil. Water mites were sampled from Miathyria marcella (Selys, 1857) and Ischnura fluviatilis (Selys, 1876).

Ácaros aquáticos são parasitas comuns de alguns insetos aquáticos em habitats de água doce. Este é o primeiro registro do ácaro Arrenurus Dugès, 1834, como parasita de Odonata no Brasil. Ácaros aquáticos foram coletados em Miathyria marcella (Selys, 1857) e Ischnura fluviatilis (Selys, 1876).

How photoperiods affect the immature development of forensically important blowfly species Chrysomya albiceps (Calliphoridae).

The purpose of this study was to verify the influence of different photoperiods on larval body weight, post-embryonic development, and viability of Chrysomya albiceps. The bioassays were performed in acclimatized chamber at 27 ± 1 °C and 60 ± 10 % relative humidity regulated by three different light and dark cycles for a period of 24 h-12:12, 24:00, and 00:24. Four replications with 50 newly hatched larvae each were used per photoperiod. The larvae were placed in container containing bovine ground meat (50 g). When mature larvae spontaneously abandoned the diet, they were individually weighed and separated into glass tubes until emergence. The larvae that did not abandon the diet were not weighed. The larvae from 24 h of photophase did not abandon the diet and pupated inside, so these larvae were not weighed and the larval and pupal developments were not registered. The mean of larval body weight did not vary between the 24 h scotophase and 12 h photophase. The mean duration of larval developmental time varied significantly when comparing the 24 h scotophase and the 12 h photophase, and the pupal developmental time also varied for the same photoperiods; in both stages, the duration of development was faster in the 24 h scotophase. The developmental time of neo-larvae to adult was verified in all photoperiods and gradually increased as photophase increased. There was a trend to augment of viability with the reduction of photophase length.

Bioactivity of latex from Euphorbia splendens var. hislopii (Euphorbiaceae) on post-embryonic development of Megaselia scalaris (Phoridae).

Larvae of Megaselia scalaris (Loew, 1866) feed on a wide range of decomposing organic matter and present a great importance to public health. This study evaluated the effect of crude latex extract from Euphorbia splendens var. hislopii (Euphorbiaceae) on post-embryonic development time of M. scalaris under laboratory conditions. The latex was used in its crude lyophilized form, dissolved in distilled water and tested in concentrations of 5 microg/mL, 10 microg/mL and 20 microg/mL. The latex was applied with the aid of an automatic pipette (1 microL/larva) on the newly-hatched larvae. Each group (the three concentrations of latex and the control group) was composed of 50 larvae and fed with 25mg of decomposing horse flesh. The experiment was made in quadruplicate. The observations were recorded daily. The data were submitted to analysis of variance (ANOVA) and Tukey's post hoc-test with a 5% significance level. The post-embryonic development time for all stages (larval, pupal and newly-hatched larvae to adult) tested with all three latex concentrations was significantly shorter than for the control group, but without any significant difference among the different concentrations. The more sensitive stages to the substance were pupal and newly-hatched larvae to adult. The viability was less than 51.5% in the three concentrations of latex in these stages and they were lower than for the control group (67.4% for pupal stage and 64% for newly-hatched larvae to adult). Therefore, it is likely that this substance has influence on the development and viability of these flies and can become a promising agent for insect pest management.