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1.
Cell Host Microbe ; 26(3): 301-303, 2019 09 11.
Artigo em Inglês | MEDLINE | ID: mdl-31513766

RESUMO

Because Drosophila larvae do not possess intestinal stem cells, it is unknown how damaged gut cells are replenished. In this issue of Cell Host & Microbe, Houtz et al. (2019) show that larvae have a unique gut repair mechanism that involves borrowing stem cells originally reserved for adult gut formation.


Assuntos
Drosophila , Roubo , Animais , Intestinos , Larva , Células-Tronco
2.
Naturwissenschaften ; 106(9-10): 52, 2019 Sep 03.
Artigo em Inglês | MEDLINE | ID: mdl-31482235

RESUMO

Parasitoid researchers have generally thought that the body size of the mother parasitoid does not affect the fitness performance of the progeny during the immature stage, as long as the progeny develop in the same environment. We reveal for the first time that this is not true for the parasitoid Echthrodelphax fairchildii (Hymenoptera: Dryinidae), which is parasitic on planthoppers. Large females ensured an increased survival rate for their progeny during the immature stage and a large body size at adult emergence. Maternal body size differentially affected the body sizes and survival rates of male and female progeny. Small females did not produce female progeny, and the survival rate of the female progeny increased more steeply with increasing maternal body size than that of the male progeny. Meanwhile, the body size of male progeny increased more steeply with increasing maternal body size. The influence of maternal body size on progeny survival to adult emergence has never been reported in insects before. In addition, large females were more likely to lay female eggs, suggesting that females control the sex ratio of progeny in response to their own body size.


Assuntos
Tamanho Corporal/fisiologia , Interações Hospedeiro-Parasita/fisiologia , Vespas/anatomia & histologia , Vespas/fisiologia , Animais , Feminino , Larva/anatomia & histologia , Larva/fisiologia , Masculino , Oviposição/fisiologia , Taxa de Sobrevida
3.
Oecologia ; 191(2): 325-334, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31535255

RESUMO

There is increasing interest in how animals respond to multiple stressors, including potential synergistic or antagonistic interaction between pathogens and perceived predation risk (PPR). For prey that exhibit phenotypic plasticity, it is unclear whether infection and PPR affect behaviour and morphology independently, or in an antagonistic or synergistic manner. Using a 2 × 2 factorial experiment involving green frog (Lithobates clamitans) tadpoles exposed to ranavirus (FV3) and larval dragonflies (Anax spp.), we assessed whether anti-predator responses were affected by infection. We found that activity and feeding were reduced additively by both stressors. Body mass of tadpoles from FV3-exposed tanks was lighter relative to control and PPR-only tanks, while metabolism was comparable across treatments. We found that FV3 exposure compromised morphometric responses to PPR in an antagonistic manner: tadpoles exposed to both treatments had restricted changes in tail depth compared to those receiving singular treatment. We conclude that multiple stressors can have complex and substantive effects on organisms, and that interactions between stressors may yield a range of responses depending on the level of exposure and sensitivity of the organism. Additional work should more fully determine mechanisms underlying the complex interplay between infection and predation risk, across a range of environmental conditions.


Assuntos
Odonatos , Ranavirus , Animais , Larva , Comportamento Predatório
4.
Vet Parasitol ; 273: 97-104, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31473450

RESUMO

This study aimed to investigate the presence of the natural transovarial transmission of tick-borne pathogens in unfed larvae obtained from engorged female ticks from domestic animals in Turkey. Larvae (n = 4530, 151 pools) obtained from 75 engorged female ticks and female carcasses were screened for the presence of certain tick-borne pathogens by PCR. The presence of transovarial transmission of Babesia occultans was detected in Hyalomma marginatum and Hy. excavatum, while Ba. ovis in Rhipicephalus bursa. Theileria annulata was detected only in Hy. excavatum and Rh. turanicus female carcasses, but not in their examined progenies. Additionally, Rickettsia aeschlimannii and Rickettsia raoultii were detected in Hy. marginatum and Dermacentor marginatus females, respectively, and all their examined larvae. Besides, Ri. slovaca was detected in a De. marginatus female carcass and its one of two examined larvae pools. The presence of mixed Ba. occultans and Ri. aeschlimannii infection was also determined in an Hy. marginatum female and its larvae. This is the first demonstration of transovarial transmission of Ba. occultans in naturally infected Hy. excavatum. These data suggested that Hy. excavatum may act as vector in the natural cycle of Ba. occultans.


Assuntos
Infecções Bacterianas/veterinária , Infecções Protozoárias em Animais/transmissão , Doenças Transmitidas por Carrapatos/veterinária , Carrapatos/microbiologia , Carrapatos/parasitologia , Animais , Animais Domésticos/microbiologia , Animais Domésticos/parasitologia , Infecções Bacterianas/microbiologia , Infecções Bacterianas/transmissão , DNA Bacteriano/genética , DNA de Protozoário/genética , Feminino , Larva/microbiologia , Larva/parasitologia , Ovário/microbiologia , Ovário/parasitologia , Reação em Cadeia da Polimerase , Infecções Protozoárias em Animais/parasitologia , Doenças Transmitidas por Carrapatos/microbiologia , Doenças Transmitidas por Carrapatos/parasitologia , Doenças Transmitidas por Carrapatos/transmissão , Turquia
5.
Dis Aquat Organ ; 135(3): 241-250, 2019 Sep 19.
Artigo em Inglês | MEDLINE | ID: mdl-31535619

RESUMO

Within communities, pathogens and parasites have the potential to indirectly influence predator-prey interactions. For instance, prey that exhibit pathology or altered traits (e.g. behavioral shifts) following infection could be more prone to predation, which is known as parasite-induced vulnerability to predation (PIVP). PIVP has been frequently documented for pathogens with trophic transmission, because predators are often critical in the pathogen's life cycle. However, for pathogens without trophic transmission, PIVP can lead to a healthy herds effect, thereby reducing transmission in the system. In this study, we explored whether the pathogen ranavirus (family Iridoviridae) enhances vulnerability of 4 species of larval amphibians (spring peepers Pseudacris crucifer, gray treefrogs Hyla versicolor, American toads Anaxyrus americanus, and northern leopard frogs Lithobates pipiens) to 2 common tadpole predators (larval green darners Anax junius [hereinafter Anax] and adult water bugs Belostoma flumineum [hereinafter Belostoma]). For each anuran species, we conducted short-term microcosm experiments to assess predation rates on individuals that were or were not exposed to virus. For 3 of the 4 species, we found that exposure to ranavirus decreased survival rates with Anax between 2- and 9-fold. However, we did not see the same trend with Belostoma, which indicates that predator identity is important in this interaction. More specifically, the higher efficiency of Anax in capturing and consuming prey, relative to Belostoma, may allow Anax to capitalize on trait changes induced by virus exposure and enhance the PIVP effect. Our results indicate that trait-mediated indirect effects could play a role in creating healthy herds in amphibian communities.


Assuntos
Anuros/parasitologia , Animais , Bufonidae , Larva , Comportamento Predatório
6.
Dis Aquat Organ ; 135(3): 251-255, 2019 Sep 19.
Artigo em Inglês | MEDLINE | ID: mdl-31535620

RESUMO

The mass decline of amphibian populations poses a serious threat to global biodiversity and ecosystem stability. The pathogenic fungus Batrachochytrium dendrobatidis (Bd) has contributed to the extirpation and extinction of hundreds of amphibian species worldwide. Bd produces potentially damaging metabolites during the host infection process that may affect amphibian growth and development, even in the absence of infection. In this experiment, Cuban tree frog Osteopilus septentrionalis tadpoles and adults were exposed once to either artificial spring water (ASW) or Bd metabolites (n = 31 tadpoles per treatment and n = 30 and 20 adults per treatment, respectively). Tadpoles exposed to Bd metabolites alone developed faster than those exposed to ASW; however, there was no difference in tadpole length, weight change, or mortality between treatments. Despite the faster developmental speed, metabolite exposure did not reduce tadpole weight or length (compared at Gosner stages 27, 29, and 31). There was no effect of treatment on adult size or mortality. These results indicate that both tadpole and adult O. septentrionalis do not appear to be negatively impacted by exposure to non-infectious Bd-contaminated water. In fact, tadpoles developed faster when exposed to metabolites and were of equal size as those in their stage cohort, implying a potential long-term benefit if faster development allows them to leave Bd-infected waters sooner.


Assuntos
Quitridiomicetos , Animais , Anuros , Biodiversidade , Ecossistema , Larva
7.
Ecotoxicol Environ Saf ; 182: 109449, 2019 Oct 30.
Artigo em Inglês | MEDLINE | ID: mdl-31398778

RESUMO

The flame retardant, tris(1,3-dichloro-2-propyl) phosphate (TDCIPP), is one of the most developmentally toxic organophosphate flame retardants (OPFRs). However, few mechanistic studies on phenotypic malformation caused by TDCIPP have been conducted. This study investigates the molecular mechanism underlying abnormal tail fin development consistently observed in zebrafish embryos exposed to TDCIPP. The results show that the defects in the tail fin (e.g., bent spine, defective caudal fin, and damaged tip) were associated with altered expression of transcription factors. The significant up-regulation of mmp9 and, among insulin-growth factor (IGF) families, igfbp-1a and igfbp1b was observed, whereas alterations in the expression of cdx4, igf1a, ifg1b, igf2b, and vegaa regulating tail development were dependent on time points. In accordance with changes in mRNA gene expression, TDCIPP impaired vessel formation and disorganized muscle in transgenic Tg(fli-GFP) zebrafish larvae. Furthermore, we found that the overexpression of mmp9 caused by TDCIPP was not linked to igfbp-1. Overall, these findings demonstrate that TDCIPP disrupts the progression of tail fin development, accompanied by defects in vessel and muscle formation in developing zebrafish embryos.


Assuntos
Desenvolvimento Embrionário/efeitos dos fármacos , Retardadores de Chama/toxicidade , Compostos Organofosforados/toxicidade , Animais , Animais Geneticamente Modificados , Retardadores de Chama/metabolismo , Larva , Organofosfatos/metabolismo , Fosfatos/metabolismo , Peixe-Zebra/embriologia , Peixe-Zebra/metabolismo
8.
Ecotoxicol Environ Saf ; 182: 109448, 2019 Oct 30.
Artigo em Inglês | MEDLINE | ID: mdl-31398781

RESUMO

The electrocoagulation (EC) technique is an alternative method of isolating natural products with the advantage of minimizing the amounts of organic solvents required for this process, which are often harmful to the environment. In this research, the EC and the conventional solvent extraction methods were used in the isolation of Stemona alkaloids from the aerial parts of Stemona aphylla. A comparison was made between the amounts of the isolated alkaloids and the solvents used. The isolated alkaloids were evaluated for their larvicidal, ovicidal and oviposition-deterrent activities against the dengue vector, Aedes aegypti. The morphology and histopatology of the alkaloid treated larvae were also investigated. Two Stemona alkaloids, (2'S)-hydroxystemofoline and stemofoline, were isolated from both the EC and the conventional method. The amounts of (2'S)-hydroxystemofoline from the EC method was about the same as that obtained from the conventional method. However, the amounts of stemofoline obtained from the EC method were about two times larger than those obtained from the conventional method. Importantly, the EC method required six times less total organic solvents. The larvicidal activity assays of (2'S)-hydroxystemofoline and stemofoline showed that these were highly effective against Aedes aegypti larvae with LC50 values of 3.91 µg/ml and 4.35 µg/ml, respectively. Whereas, the crude EC extract (LC50 = 11.86 µg/ml) showed greater larvicidal activity than the crude extract obtained from the conventional extraction method (LC50 = 53.40 µg/ml). The morphological observations of the (2'S)-hydroxystemofoline and the stemofoline treated larvae revealed that the anal gills were the sites of aberrations. A histopathological study showed that larvae treated with these alkaloids had cytopathological alterations to the epithelial cells of the midgut. At a concentration 40 µg/ml (2'S)-hydroxystemofoline showed 100% ovicidal activity on 24 h old eggs while stemofoline showed 97.2%. Furthermore, the oviposition-deterrent effects of (2'S)-hydroxystemofoline and stemofoline, at a concentration of 80 µg/ml were 99.5% and 97.2%, respectively.


Assuntos
Aedes/efeitos dos fármacos , Alcaloides/toxicidade , Controle de Mosquitos/métodos , Componentes Aéreos da Planta/química , Extratos Vegetais/toxicidade , Stemonaceae/química , Animais , Dengue/transmissão , Vetores de Doenças , Eletrocoagulação , Feminino , Compostos Heterocíclicos de 4 ou mais Anéis , Inseticidas/farmacologia , Larva/efeitos dos fármacos , Mosquitos Vetores , Oviposição/efeitos dos fármacos
9.
BMC Plant Biol ; 19(1): 338, 2019 Aug 02.
Artigo em Inglês | MEDLINE | ID: mdl-31375063

RESUMO

BACKGROUND: In native environments plants frequently experience simultaneous or sequential unfavourable abiotic and biotic stresses. The plant's response to combined stresses is usually not the sum of the individual responses. Here we investigated the impact of cold on plant defense against subsequent herbivory by a generalist and specialist insect. RESULTS: We determined transcriptional responses of Arabidopsis thaliana to low temperature stress (4 °C) and subsequent larval feeding damage by the lepidopteran herbivores Mamestra brassicae (generalist), Pieris brassicae (specialist) or artificial wounding. Furthermore, we compared the performance of larvae feeding upon cold-experienced or untreated plants. Prior experience of cold strongly affected the plant's transcriptional anti-herbivore and wounding response. Feeding by P. brassicae, M. brassicae and artificial wounding induced transcriptional changes of 1975, 1695, and 2239 genes, respectively. Of these, 125, 360, and 681 genes were differentially regulated when cold preceded the tissue damage. Overall, prior experience of cold mostly reduced the transcriptional response of genes to damage. The percentage of damage-responsive genes, which showed attenuated transcriptional regulation when cold preceded the tissue damage, was highest in M. brassicae damaged plants (98%), intermediate in artificially damaged plants (89%), and lowest in P. brassicae damaged plants (69%). Consistently, the generalist M. brassicae performed better on cold-treated than on untreated plants, whereas the performance of the specialist P. brassicae did not differ. CONCLUSIONS: The transcriptional defense response of Arabidopsis leaves to feeding by herbivorous insects and artificial wounding is attenuated by a prior exposure of the plant to cold. This attenuation correlates with improved performance of the generalist herbivore M. brassicae, but not the specialist P. brassicae, a herbivore of the same feeding guild.


Assuntos
Arabidopsis/fisiologia , Herbivoria , Animais , Arabidopsis/metabolismo , Borboletas/fisiologia , Resposta ao Choque Frio , Dieta , Regulação da Expressão Gênica de Plantas/fisiologia , Herbivoria/fisiologia , Larva , Mariposas/fisiologia , Folhas de Planta/metabolismo , Folhas de Planta/fisiologia , Transcriptoma
10.
J Agric Food Chem ; 67(33): 9210-9219, 2019 Aug 21.
Artigo em Inglês | MEDLINE | ID: mdl-31390203

RESUMO

The insecticidal and antifeedant activities of five 7-chloro-4-(1H-1,2,3-triazol-1-yl)quinoline derivatives were evaluated against the maize armyworm, Spodoptera frugiperda (J.E. Smith). These hybrids were prepared through a copper-catalyzed azide alkyne cycloaddition (CuAAC, known as a click reaction) and displayed larvicidal properties with LD50 values below 3 mg/g insect, and triazolyl-quinoline hybrid 6 showed an LD50 of 0.65 mg/g insect, making it 2-fold less potent than methomyl, which was used as a reference insecticide (LD50 = 0.34 mg/g insect). Compound 4 was the most active antifeedant derivative (CE50 = 162.1 µg/mL) with a good antifeedant index (56-79%) at concentrations of 250-1000 µg/mL. Additionally, triazolyl-quinoline hybrids 4-8 exhibited weak inhibitory activity against commercial acetylcholinesterase from Electrophorus electricus (electric-eel AChE) (IC50 = 27.7 µg/mL) as well as low anti-ChE activity on S. frugiperda larvae homogenate (IC50 = 68.4 µg/mL). Finally, molecular docking simulations suggested that hybrid 7 binds to the catalytic active site (CAS) of this enzyme and around the rim of the enzyme cavity, acting as a mixed (competitive and noncompetitive) inhibitor like methomyl. Triazolyl-quinolines 4-6 and 8 inhibit AChE by binding over the perimeter of the enzyme cavity, functioning as noncompetitive inhibitors. The results described in this work can help to identify lead triazole structures from click chemistry for the development of insecticide and deterrent products against S. frugiperda and related insect pests.


Assuntos
Inseticidas/síntese química , Inseticidas/farmacologia , Larva/efeitos dos fármacos , Quinolinas/química , Quinolinas/farmacologia , Spodoptera/efeitos dos fármacos , Acetilcolinesterase/química , Acetilcolinesterase/metabolismo , Animais , Inibidores da Colinesterase/síntese química , Inibidores da Colinesterase/química , Inibidores da Colinesterase/farmacologia , Química Click , Simulação por Computador , Proteínas de Insetos/antagonistas & inibidores , Proteínas de Insetos/química , Proteínas de Insetos/metabolismo , Inseticidas/química , Larva/enzimologia , Larva/crescimento & desenvolvimento , Simulação de Acoplamento Molecular , Doenças das Plantas/parasitologia , Spodoptera/enzimologia , Spodoptera/crescimento & desenvolvimento , Zea mays/parasitologia
11.
J Chem Ecol ; 45(8): 693-707, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31367970

RESUMO

Crop domestication and selective breeding have altered plant defense mechanisms, influencing insect-plant interactions. A reduction in plant resistance/tolerance against herbivory is generally expected in domesticated species, however, limited efforts have been made to compare inducibility of plant defenses between wild and domesticated genotypes. In the present study, the inducibility of several plant defense mechanisms (e.g. defensive chemicals, trichomes, plant volatiles) were investigated, and the performance and preference of the herbivore Helicoverpa zea were measured in three different tomato genotypes; a) wild tomato, Solanum pimpinellifolium L. (accession LA 2093), b) cherry tomato, S. lycopersicum L. var. cerasiforme (accession Matts Wild Cherry), and c) cultivated tomato, S. lycopersicum L. var. Better Boy). Enhanced inducibility of defensive chemicals, trichomes, and plant volatiles in the cultivated tomato, and a higher level of constitutive plant resistance against herbivory in the wild genotype was observed. When comparing the responses of damaged vs. undamaged leaves, the percent reduction in larval growth was higher on damaged leaves from cultivated tomato, suggesting a higher induced resistance compared to other two genotypes. While all tomato genotypes exhibited increased volatile organic compound (VOCs) emissions in response to herbivory, the cultivated variety responded with generally higher levels of VOCs. Differences in VOC patterns may have influenced the ovipositional preferences, as H. zea female moths significantly preferred laying eggs on the cultivated versus the wild tomato genotypes. Selection of traits during domestication and selective breeding could alter allocation of resources, where plants selected for higher yield performance would allocate resources to defense only when attacked.


Assuntos
Lycopersicon esculentum/química , Mariposas/fisiologia , Solanum/química , Animais , Comportamento Animal/efeitos dos fármacos , Catecol Oxidase/metabolismo , Feminino , Genótipo , Herbivoria , Larva/fisiologia , Lycopersicon esculentum/genética , Lycopersicon esculentum/metabolismo , Oviposição/efeitos dos fármacos , Fenóis/análise , Folhas de Planta/química , Folhas de Planta/metabolismo , Folhas de Planta/parasitologia , Proteínas de Plantas/análise , Análise de Componente Principal , Inibidores de Proteases/química , Solanum/genética , Solanum/metabolismo , Compostos Orgânicos Voláteis/química , Compostos Orgânicos Voláteis/metabolismo , Compostos Orgânicos Voláteis/farmacologia
12.
J Chem Ecol ; 45(8): 715-724, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31385154

RESUMO

Plants emit a specific blend of volatiles in response to herbivory and these volatiles, which often attract predators and parasitoids function as an indirect plant defense. The impact of plant volatiles in shaping herbivore defenses is unclear. Here, we report that specific plant volatiles induce immune responses in the polyphagous herbivore, Spodoptera litura. We characterized the hemocyte profile and established their functional significance with respect to ontogeny and exposure to specific plant volatiles. Fifth instar larvae showed the highest number and hemocytes diversity. We characterized seven different types of hemocytes, of which granulocytes performed phagocytosis, oenocytoids showed melanization activity, and plasmatocytes along with granulocytes and oenocytoids were found to be involved in encapsulation. Among the six volatiles tested, exposure to (E)-ß-ocimene caused the highest increase in total hemocytes number (THC) followed by linalool and (Z)-3-hexenyl acetate exposure. Although THC did not differ between these three volatile treatments, circulating hemocytes diversity varied significantly. (E)-ß-ocimene exposure showed higher number of plasmatocytes and phenol oxidase activity. The interaction of the parasitic wasp Bracon brevicornis with (E)-ß-ocimene exposed larvae was poor in terms of delayed paralysis and lower egg deposition. In choice assays, the wasp showed clear preference towards control larvae indicating (E)-ß-ocimene treatment renders the host unattractive. Hemocyte profiles post-parasitoid exposure and (E)-ß-ocimene treatment were similar indicating cue-based priming. When challenged with Bacillus thuringiensis, linalool exposure resulted in the highest survival as compared to other volatiles. Our results show that specific HIPVs can modulate cellular immunity of S. litura, revealing a new role for HIPVs in tri-trophic interactions.


Assuntos
Compostos Orgânicos Voláteis/farmacologia , Vespas/fisiologia , Alcenos/farmacologia , Animais , Comportamento Animal/efeitos dos fármacos , Hemócitos/citologia , Hemócitos/efeitos dos fármacos , Hemócitos/metabolismo , Herbivoria , Interações Hospedeiro-Parasita , Sistema Imunitário/efeitos dos fármacos , Sistema Imunitário/metabolismo , Larva/fisiologia , Monofenol Mono-Oxigenase/metabolismo , Monoterpenos/farmacologia , Oviposição/efeitos dos fármacos , Fagocitose/efeitos dos fármacos , Plantas/química , Plantas/metabolismo , Plantas/parasitologia , Compostos Orgânicos Voláteis/química , Vespas/imunologia
13.
Rev Soc Bras Med Trop ; 52: e20190135, 2019 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-31390442

RESUMO

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.


Assuntos
Bacillus thuringiensis , Toxinas Bacterianas/farmacologia , Moscas Domésticas/efeitos dos fármacos , Inseticidas/farmacologia , Larva/efeitos dos fármacos , Análise de Variância , Animais , Contagem de Colônia Microbiana , Exotoxinas , Microscopia Eletrônica de Transmissão , Controle Biológico de Vetores/métodos , Reprodutibilidade dos Testes
14.
Waste Manag ; 96: 65-74, 2019 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-31376971

RESUMO

Fly larvae composting is an emerging waste treatment alternative with great potential to increase revenue from food waste management. For wider implementation, fly larvae composting has to be evaluated in comparison with conventional systems, based on direct greenhouse gas (GHG) emission data for the treatment process, which are currently limited. This study evaluated direct emissions of CO2, CH4, N2O and NH3 from composting of food waste using black soldier fly (BSF) larvae (Hermetia illucens). Use of BSF larvae-associated bacteria in 7-day pre-treatment and seeding at larvae treatment start were evaluated and compared to larvae treatment without bacteria addition. The treatments were performed in a set of 14-day laboratory-scale experiments. Mean substrate reduction was 49 ±â€¯8% and bioconversion ratio was 24 ±â€¯8% (both dry matter basis). Direct GHG emissions from the fly larvae treatment process were generally very small, with emissions of CH4 and N2O equivalent to 0.38 kg CO2-equivalents per ton food waste treated assuming global warming potential over 100 years, while mean total CO2 emissions were 96 g CO2 per kg food waste treated. Additional emissions could be expected to occur in the pre-treatment process, which did not provide any significant improvement in bioconversion ratio or reduction in total GHG emissions during treatment. Similarly, use of BSF larvae-associated bacteria did not significantly improve process efficiency. No NH3 emissions were detected, as reflected in total N mass balance over the treatment cycle. The results show that total direct GHG emissions from food waste treatment by fly larvae composting are lower than those from conventional food waste treatment, and that pre-treatment and seeding of food waste with BSF larvae-associated bacteria do not further reduce total GHG emissions.


Assuntos
Compostagem , Gases de Efeito Estufa , Gerenciamento de Resíduos , Animais , Efeito Estufa , Larva
15.
Pestic Biochem Physiol ; 159: 41-50, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31400783

RESUMO

Emerging fungal phytodiseases are a food security threat and novel fungicides are in an urgent need. Herein, a series of isobutyrophenone derivatives were designed and synthesized. The derivatives exhibited excellent fungicidal activities against seven fungi. The structure-activity relationship (SAR) study indicated that the introduction of a bromo group at the position 3 or 5 of the phenyl ring, as well as esterification of the 4-hydroxy with a chloroacetyl group, could substantially increase the antifungal activity and spectrum of the compounds. Among all 23 compounds, 2-bromo-3-hydroxy-4-isobutyryl-6-methylphenyl 2-chloroacetate (12b) showed the highest fungicidal activity against all seven tested fungal pathogens with EC50 values ranging from 1.22 to 39.94 µg/mL and exhibited the most potent inhibition against class II fructose-1,6-bisphosphate aldolase with an IC50 of 3.63 µM. The lead compounds were proven to be safe to NIH3T3/293 T cells and silkworm larvae, and relatively stable under different harsh conditions. Detached fruit tests showed the practical potential of lead compounds for fruit (or plant) protection. Taken together, our results indicated that the isobutyrophenone derivatives could be further optimized and developed as advanced leads for new fungicides.


Assuntos
Antifúngicos/química , Antifúngicos/metabolismo , Frutose-Bifosfato Aldolase/metabolismo , Animais , Bombyx/metabolismo , Linhagem Celular , Frutose-Bifosfato Aldolase/genética , Humanos , Larva/metabolismo , Camundongos , Testes de Sensibilidade Microbiana , Estrutura Molecular , Células NIH 3T3 , Relação Estrutura-Atividade
16.
Pestic Biochem Physiol ; 159: 85-90, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31400788

RESUMO

RNA interference (RNAi) is a potentially useful pest control method because of its high specificity. Silencing the expression of important RNAi target genes of pests will block important biological processes and reduce pest damage. Ecdysone is a unique arthropod hormone and the ecdysone receptor (EcR) is a key factor in molting pathway. We investigated the possibility that dsRNA targeting of the EcR of Tetranychus cinnabarinus (TcEcR) could effectively block development from larvae to adults. The mRNA level of TcEcR was highest in the larva stage, and 73.1% of the mites failed to survive the larva stage when TcEcR expression was silenced. Only 11.7% of T. cinnabarinus ingesting dsRNA successfully developed into adults, while 86.7% in the control succeeded in molting across each stage. RNAi significantly increased the developmental intervals of T. cinnabarinus. Under the effects of dsRNA, development times for the larva and first nymph doubled. Phenotype of body size change and death were observed during the development of T. cinnabarinus ingesting dsRNA. These findings suggest that RNAi is a potential means for the control of T. cinnabarinus. Genes in hormone pathways such as EcR are possible RNAi targets.


Assuntos
Larva/metabolismo , Interferência de RNA/fisiologia , Receptores de Esteroides/metabolismo , Tetranychidae/metabolismo , Animais , Tamanho Corporal , Plantas Geneticamente Modificadas/crescimento & desenvolvimento , Plantas Geneticamente Modificadas/metabolismo , RNA de Cadeia Dupla/genética , Receptores de Esteroides/genética , Tetranychidae/crescimento & desenvolvimento
17.
J Forensic Leg Med ; 67: 28-36, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31398663

RESUMO

The application of forensic entomotoxicology in investigations of death by poisoning has gained popularity as insects serves as an alternative specimen (evidence) when conventional toxicological samples have degraded or are no longer available. Successful detection, identification, and quantification of drugs and toxic substances from insects have been demonstrated through various research experiments. In the present review paper, role of insects as toxicological sample, its collection and preservation, analysis using various instrumental techniques, and trends in the use of analytical techniques have been discussed. Limitations hindering the growth of this field and the way forward for future studies have been highlighted. In addition, the effect of poisons on insects used for postmortem interval estimation has been described.


Assuntos
Entomologia , Comportamento Alimentar , Toxicologia Forense/métodos , Envenenamento/diagnóstico , Mudanças Depois da Morte , Animais , Depressores do Sistema Nervoso Central/análise , Besouros , Dípteros , Etanol/análise , Humanos , Larva , Extração Líquido-Líquido , Praguicidas/análise , Preparações Farmacêuticas/análise , Extração em Fase Sólida , Xenobióticos
18.
J Forensic Leg Med ; 67: 37-48, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31419763

RESUMO

Previous studies have begun to characterize the microbial community dynamics of the skin, soil, gut, and oral cavities of decomposing remains. One area that has yet to be explored in great detail is the microbiome of the fly larval mass, the community of immature flies that plays a significant role in decomposition. The current study aimed to characterize the microbiology and chemistry of larval masses established on pig (Sus scrofa domesticus) carcasses and to determine if these characteristics have potential as temporal evidence. Carcasses (n = 3) were decomposed on the soil surface of a tropical habitat on Oahu, Hawaii, USA and sampled over three days at 74 h, 80 h, 98 h, 104 h, 122 h, and 128 h (∼85-142 Accumulated Degree Days) postmortem. Larval masses were analyzed via high-throughput 16S rRNA sequencing and in situ chemical measurements (pH, temperature, oxidation-reduction potential). A trend was observed that resulted in three distinct microbial communities (pre-98 h, 98 h, and post-98 h). The oxidation-reduction potential (Eh) of larval masses apparently regulated microbial community structure with the most negative Eh being associated with the least rich and diverse microbial communities. Overall, a significant interaction between time and taxa was observed, particularly with bacterial phyla Firmicutes and Proteobacteria. The current results provide new insight into the microbial community and chemical parameters of larval masses and indicate a temporal shift that could be further studied as a PMI estimator.


Assuntos
Comportamento Alimentar , Larva/química , Larva/microbiologia , Microbiota , Mudanças Depois da Morte , Animais , Bactérias/genética , Entomologia , Patologia Legal , Hawaii , Concentração de Íons de Hidrogênio , Modelos Animais , Oxirredução , RNA Ribossômico 16S , Análise de Sequência de RNA , Suínos
19.
Dis Aquat Organ ; 135(2): 135-150, 2019 Aug 08.
Artigo em Inglês | MEDLINE | ID: mdl-31392966

RESUMO

American bullfrogs Lithobates catesbeianus are thought to be important in the global spread of ranaviruses-often lethal viruses of cold-blooded vertebrates-because they are commonly farmed, dominate international trade, and may be 'carriers' of ranavirus infections. However, whether American bullfrogs are easily infected and maintain long-lasting ranavirus infections, or are refractory to or rapidly clear infections, remains unknown. We tracked the dynamics of ranavirus in American bullfrogs through time and with temperature in multiple types of samples and also screened shipments from commercial suppliers to determine whether we could detect subclinical infections. Collectively, we found that tadpoles and juveniles were commonly infected at moderate doses, and while some died, others controlled and appeared to clear their infections. Some individuals, however, harbored subclinical infections for up to 49 d, suggesting that American bullfrogs may be important carriers. Indeed, tadpoles and metamorphosed frogs from 2 of 5 commercial suppliers harbored subclinicial infections. Juveniles at warmer temperatures had less intense but still persistent infections. Because diagnostic performance was strongly related to infection intensity, non-lethal samples (i.e. tail or toe clips, swabs, and environmental DNA) had only a moderate chance of detecting subclinical infections. Even internal tissues may fail to detect subclinical infections. However, viral shedding was correlated with the intensity of infection, so while subclinically infected tadpoles shed virus for 35-49 d, the low levels might lead to little transmission. We suggest that a quantitative focus on virus dynamics within hosts can provide a more nuanced view of ranavirus infections and the risk presented by American bullfrogs in trade.


Assuntos
Infecções por Vírus de DNA , Ranavirus , Animais , Anuros , Infecções por Vírus de DNA/veterinária , Larva , Rana catesbeiana , Estados Unidos
20.
Rev Soc Bras Med Trop ; 52: e20180459, 2019 Jul 29.
Artigo em Inglês | MEDLINE | ID: mdl-31365621

RESUMO

INTRODUCTION: The ability of Vitex trifolia and Vitex negundo essential oils to kill Aedes aegypti and Culex quinquefasciatus larvae was evaluated. METHODS: The larvae were treated with their respective essential oils at 50-125 ppm concentration. RESULTS: LC50 and LC90 for V. trifolia against Ae. aegypti and C. quinquefasciatus, and those for V. negundo against Ae. aegypti were 57.7+0.4, 77.9+0.9 ppm and 55.17+3.14, 78.28+2.23 ppm, and 50.86+0.9, 73.12+1.3 ppm, respectively. Eucalyptol and caryophyllene were the major components in Vitex trifolia and Vitex negundo essential oil, respectively. CONCLUSIONS: This study revealed potential larvicidal properties of essential oil from V. trifolia.


Assuntos
Aedes/efeitos dos fármacos , Inseticidas/farmacologia , Larva/efeitos dos fármacos , Mosquitos Vetores/efeitos dos fármacos , Óleos Voláteis/farmacologia , Vitex/química , Animais , Inseticidas/isolamento & purificação , Dose Letal Mediana , Óleos Voláteis/isolamento & purificação
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