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Despite the wide distribution and persistence of microplastics (MPs), their interactive effects with molluscicides are unknown. Schistosomiasis, a neglected tropical disease, affects 236.6 million people worldwide. Niclosamide (NCL) is the only molluscicide recommended by the World Health Organization (WHO) and it is used to control the population of Schistosoma spp.'s intermediate host. Thus, this study aimed to evaluate of the interaction between polyethylene (PE) MPs and NCL, and their associated toxicity in the freshwater snail Biomphalaria glabrata (Say 1818). Weathered PE MPs were characterized and theoretical analysis of NCL-MP adsorption nature was made using quantum mechanical calculations. The toxicity of NCL isolated (0.0265 to 0.0809 mg L-1) and under interaction with PE MPs (3400 µg L-1) in B. glabrata embryos and newly hatched snails was analyzed. In silico analysis confirmed the adsorption mechanisms of NCL into PE MPs. PE MPs decreased the NCL toxicity to both B. glabrata developmental stages, increasing their survival and NCL lethal concentrations, indicating concerns regarding NCL use as molluscicide in aquatic environments polluted by MPs. In conclusion, MPs may change the efficiency of chemicals used in snail control programs.

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Limnoperna fortunei, the golden mussel, is a bivalve mollusk considered an invader in South America. This species is responsible for ecological and economic damages due to its voluminous fouling capability. Chemical biocides such as MXD-100™ and sodium dichloroisocyanurate (NaDCC) are often used to control L. fortunei infestations in hydraulic systems. Thus, we proposed to investigate the effects of different periods (24, 48 and 72 h) of exposure to MXD-100™ (0.56 mg L-1) and NaDCC (1.5 mg L-1) on the gills of L. fortunei through morphological and molecular analyses. NaDCC promoted progressive morphological changes during the analyzed periods and only an upregulation of SOD and HSP70 expression during the first 24 h of exposure. MXD-100™ led to severe morphological changes from the first period of exposure, in addition to an upregulation of SOD, CAT, HSP70 and CYP expression during the first 24 h. In contrast, MXD-100™ led to a downregulation of CAT transcription between 24 and 48 h. In static conditions, NaDCC causes lethal damage after 72 h of exposure, and that exposure needs to be continuous to achieve the control of the species. Meanwhile, the MXD-100™ treatment presented several effects during the first 24 h, showing acute toxicity in a shorter period of time.

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Biomphalaria glabrata snails constitute the main vector of schistosomiasis in Brazil, and Bauhinia monandra Kurz, the leaves of which contain BmoLL lectin with biocidal action, is a plant widely found on continents in which the disease is endemic. This work describes the composition of B. monandra preparations and the effect on embryos and adult snails, their reproduction parameters and hemocytes. We also describe the results of a comet assay after B. glabrata exposure to sublethal concentrations of the preparations. Additionally, the effects of the preparations on S. mansoni cercariae and environmental monitoring with Artemia salina are described. In the chemical evaluation, cinnamic, flavonoid and saponin derivatives were detected in the two preparations assessed, namely the saline extract and the fraction. Both preparations were toxic to embryos in the blastula, gastrula, trochophore, veliger and hippo stages (LC50 of 0.042 and 0.0478; 0.0417 and 0.0419; 0.0897 and 0.1582; 0.3734 and 0.0974; 0.397 and 0.0970 mg/mL, respectively) and to adult snails (LC50 of 6.6 and 0.87 mg/mL, respectively), which were reproductively affected with decreased egg deposition. In blood cell analysis, characteristic cells for apoptosis, micronucleus and binucleation were detected, while for comet analysis, different degrees of nuclear damage were detected. The fraction was able to cause total mortality of the cercariae and did not present environmental toxicity. Therefore, B. monandra preparations are promising in combating schistosomiasis since they can control both the intermediate host and eliminate the infectious agent, besides being safe to the environment.

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Schistosomiasis is caused by the intestinal parasite Schistosoma mansoni. Individuals are affected by schistosomiasis when they are exposed to aquatic environments contaminated with Schistosoma cercariae that emerged from the infected intermediate host mollusk of the genus Biomphalaria. The WHO recommends using molluscicidal products to reduce the snail population and disease transmission. The WHO encourages the search for alternative substances in schistosomiasis control. Natural products are seen as a promising alternative because they are abundant in countries where schistosomiasis is endemic and have many different substances in their extracts, impairing cases of resistance. Therefore, the nanoemulsion effect of a butanol-soluble fraction of Sideroxylon obtusifolium leaves was evaluated against three study points in the biological cycle of the disease, that is, adults and young Biomphalaria glabrata, spawning by the host mollusk, and infectious larvae of the parasite. Extract-SOB (butanol fraction) and nano-SOB (nanoemulsion) demonstrated promising activity in adult B. glabrata population control with an LC50 of 125.4 mg/L, an LC90 of 178.1 mg/L, an LC50 of 75.2 mg/L, and an LC90 of 97 mg/L. Nano-SOB presented greater potency against young B. glabrata, with an LC90 of 72.1 mg/L and an LC50 of 58.3 mg/L. Still, relevant activity against S. mansoni cercariae was eliminated in 4 h (LC90: 34.6 mg/L). Nano-SOB reduced viable spawning by approximately 30% at 178.1 and 97 mg/L. Referring to most substances in this extract, quercetin-3-rhamnosyl-(1-6)-galactoside and hyperoside may cause low environmental toxicity and human toxicity according to in silico analysis. Thus, nano-SOB is a promising agent to combat B. glabrata population growth and schistosomiasis transmission.

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Green nanoparticles (GNPs), mainly green silver nanoparticles (Ag NPs), have been recommended as sustainable and eco-friendly technologies to control vectors and intermediate hosts. The aim of the current study is to carry out a historical and systematic literature review about the use of green plant-based Ag NPs (GP-Ag NPs) to control medically important mosquito, tick and gastropods. Data about the number of studies published per year, geographical distribution of studies (mailing address of the corresponding author), synthesis type (plant species, plant structure and extract types), physicochemical properties of GP-Ag NPs, experimental designs, developmental stages and the toxic effects on mosquitoes, ticks and gastropods were summarized and discussed. Revised data showed that GP-Ag NPs synthesis and toxicity in mosquitoes, ticks and snails depend on plant species, plant part, extract types, exposure condition and on the analyzed species. GP-Ag NPs induced mortality, tissue damage, biochemical and behavioral changes in mosquitoes and reduced their fecundity, oviposition, egg hatching and longevity. Ticks exposed to GP-Ag NPs presented increased mortality and reduced oviposition, while on snails, studies demonstrated mortality, oxidative stress, and DNA damage. Immune responses were also observed in snails after their exposure to GP-Ag NPs. GP-Ag NPs reduced the reproduction and population of several vectors and intermediate hosts. This finding confirms their potential to be used in gastropod control programs. Future studies about current gaps in knowledge are recommended.

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Schistosomiasis has been controlled for more than 40 years with a single drug, praziquantel, and only one molluscicide, niclosamide, raising concern of the possibility of the emergence of resistant strains. However, the molecular targets for both agents are thus far unknown. Consequently, the search for lead compounds from natural sources has been encouraged due to their diverse structure and function. Our search for natural compounds with potential use in schistosomiasis control led to the identification of an algal species, Laurencia dendroidea, whose extracts demonstrated significant activity toward both Schistosoma mansoni parasites and their intermediate host snails Biomphalaria glabrata. In the present study, three seaweed-derived halogenated sesquiterpenes, (-)-elatol, rogiolol, and obtusol are proposed as potential lead compounds for the development of anthelminthic drugs for the treatment of and pesticides for the environmental control of schistosomiasis. The three compounds were screened for their antischistosomal and molluscicidal activities. The screening revealed that rogiolol exhibits significant activity toward the survival of adult worms, and that all three compounds showed activity against S. mansoni cercariae and B. glabrata embryos. Biomonitored fractioning of L. dendroidea extracts indicated elatol as the most active compound toward cercariae larvae and snail embryos.

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Iron oxide nanoparticles (IONPs) have been indicated for the control of parasites and intermediate hosts, as well as applications in several sectors of nanomedicine. However, knowledge regarding its toxicity, mechanisms of action and the role of functionalization in gastropods that act as intermediate hosts of neglected disease parasites is still scarce. The present study aimed to evaluate the toxicity of lauric acid bilayer-functionalized IONPs (LA-IONPs), lauric acid isolated (LA) and iron ions in embryos and newly-hatched Biomphalaria glabrata. The snails were exposed to different concentrations of IONPs, LA and iron ions (1.0-97.65 mg L-1) during 144 h (embryos) and 96 h (newly-hatched) and multiple parameters were analyzed, such as mortality, hatching rate, developmental delay, and morphological changes. The results showed that both iron forms (LA-IONPs and iron ions) and LA promoted mortality, hatching inhibition and morphological changes in snail embryos in a concentration-dependent patterns. Embryos also showed iron bioaccumulation after exposure to both iron forms. High toxicity was observed in newly-hatched snails compared to embryos, indicating the protective role of ovigerous masses during the early developmental stages. LA induced high developmental toxicity compared to LA-IONPs and iron ions. Results showed the molluscicide activity of LA-IONPs and isolated LA, indicating their potential use as molluscicide in the snail control program.

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This study describes for the first time the effect of saline extract and Parkia pendula seed fraction on Biomphalaria glabrata adult embryos and molluscs well as the reproductive parameters (fecundity and fertility) and survival, in addition to cytotoxicity and genotoxicity through the profile of blood cells after exposure to sublethal concentrations. Furthermore, we analyzed the action of both preparations against the cercariae of Schistosoma mansoni and their environmental safety using the bioindicator Artemia salina. The saline extract and fraction showed toxic effects for embryos (CL90 of 464.25, 479.62, 731.28, 643.28, 408.43 and 250.94, 318.03, 406.12, 635.64, 1.145 mg/mL, for blastula, gastrula, trocophore, veliger and hippo stage respectively), adult snails after 24 h of exposure (CL90 of 9.50 and 10.92 mg/mL, respectively) with increased mortality after 7 days of observation and significant decrease (p <0.05; p < 0.01 and p < 0.001) in egg mass deposition. At sublethal concentrations, an increase in quantitative and morphological changes in hemocytes was observed, and in the genotoxicity/comet assay analysis, varying degrees of nuclear damage were detected. In addition, the saline extract showed changes in the motility of the cercariae, while the fraction howed toxicity from a concentration of 1.0 mg/mL. The saline extract showed toxicity to A. salina at the highest concentrations (3.0, 4.0 and 5.0 mg/mL), while the fraction did not show ecotoxicity. Thus, the saline extract and fraction was promising in combating schistosomiasis by eliminating the intermediate host and causing alterations and/or mortality to the infectious agent.

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Dysphania ambrosioides (L.) Mosyakin & Clemants, known as santa maria herb, is a medicinal plant used on pest control and to treat parasitic diseases. Due to its potential for pest control, the aim of this work was to determine the chemical composition of D. ambrosioides essential oil and evaluate its molluscicidal effect on Biomphalaria tenagophila, which is an intermediate host for the Schistosoma mansoni trematode, that is responsible for causing human schistosomiasis. The essential oil extracted from its leaves showed 87% of (Z)-ascaridole and 100% of mortality against B. tenagophila at 10 ppm after 24 h of experiment. LC50 and LC90 values were, respectively, 2.40 (1.90-2.99) ppm and 8.75 (6.39-14.12) ppm. D. ambrosioides essential oil proved to be a promising natural molluscicide against schistosomiasis when compared with commercial products.

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Schistosomiasis has been controlled for more than 40 years with a single drug, praziquantel, and only one molluscicide, niclosamide, raising concern of the possibility of the emergence of resistant strains. However, the molecular targets for both agents are thus far unknown. Consequently, the search for lead compounds from natural sources has been encouraged due to their diverse structure and function. Our search for natural compounds with potential use in schistosomiasis control led to the identification of an algal species, Laurencia dendroidea, whose extracts demonstrated significant activity toward both Schistosoma mansoni parasites and their intermediate host snails Biomphalaria glabrata. In the present study, three seaweed-derived halogenated sesquiterpenes, (−)-elatol, rogiolol, and obtusol are proposed as potential lead compounds for the development of anthelminthic drugs for the treatment of and pesticides for the environmental control of schistosomiasis. The three compounds were screened for their antischistosomal and molluscicidal activities. The screening revealed that rogiolol exhibits significant activity toward the survival of adult worms, and that all three compounds showed activity against S. mansoni cercariae and B. glabrata embryos. Biomonitored fractioning of L. dendroidea extracts indicated elatol as the most active compound toward cercariae larvae and snail embryos.

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Schistosomiasis, a parasitic disease caused by trematodes of the genus Schistosoma, is the second most prevalent parasitic disease in the world. It affects around 200 million people. Clinical treatment, prophylaxis, and prevention are performed in countries susceptible to schistosomiasis. In the pharmacological treatment for an acute form of schistosomiasis, the use of antiparasitics, mainly praziquantel, is more common. As an alternative way, prevention methods such as reducing the population of intermediate hosts (mollusks) with molluscicides are important in the control of this disease by interrupting the biological cycle of this etiological parasite. Despite the importance of pharmacological agents and molluscicides, they have side effects and environmental toxicity. In addition, they can lead to the development of resistance enhancing of parasites, and lead to the search for new and effective drugs, including resources of vegetal origin, which in turn, are abundant in the affected countries. Thus, the purpose of this review is to summarize recent studies on botanical products with potential for the control of schistosomiasis, including anti-Schistosoma and molluscicide activities. In addition, species and plant derivatives according to their origin or geographical importance indicating a possible utility of local resources for countries most affected by the disease are presented.

RESUMO

The emerging growth of nanotechnology has attracted great attention due to its application in the parasite and intermediate host control. However, the knowledge concerning the mechanism of action (MoA) and toxicity of nanomaterials (NMs) to snails remain unclear. In this context, the present study revised the historical use of snails as experimental models in nanotoxicological studies and summarized the MoA and toxicity of NMs in aquatic and land snails. The data concerning the bioaccumulation, reproductive and transgenerational toxicity, embryotoxicity, genotoxicity and potential molluscicidal activity of NMs were revised. Furthermore, the data about the experimental conditions, such as exposure time, concentrations, cell and tissue-specific responses, snail species and nanoparticle types are discussed. Revised data showed that the toxic effects of NMs were reported for 21 snail species with medical, veterinary and ecological importance. The NM toxicity to snails is dependent on the physical and chemical properties of NMs, as well as their environmental transformation and experimental design. The NM bioaccumulation on snails was related to several toxic effects, such as reactive oxygen species (ROS) production, oxidative stress, following by oxidative damage to DNA, lipids and proteins. The NM metabolism in snails remains unknown. Results showed the potential use of NMs in the snail control program. Also, significant research gaps and recommendations for future researches are indicated. The present study confirms that snails are suitable invertebrate model system to assess the nanotoxicity.

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Silver nanoparticles (Ag NPs) have been applied in several commercial products due to their antimicrobial properties, while their molluscicide properties, mode of action and toxicity to snail species remain unclear. In this study, the comparative toxicity of polyvinylpyrrolidone (PVP)-functionalized Ag NPs and their dissolved counterpart (Ag ions) was analyzed during the early developmental stages of the freshwater snail Biomphalaria glabrata, intermediate host of Schistosoma mansoni. Ag NPs were synthesized and characterized by multiple techniques, and the snail embryotoxicity was analyzed in terms of mortality, hatching, developmental stages and morphological alterations, while the acute toxicity to newly-hatched snails was analyzed by mortality and behavioral impairments. Results showed that both Ag forms induced mortality, hatching delay and morphological alterations (especially hydropic abnormalities) in snail embryos in a concentration and exposure time dependent patterns. Ag NPs showed low embryotoxic effects and similar toxicity for newly-hatched snails when compared to their dissolved counterparts, indicating that the nanotoxicity was dependent of snail developmental stages. The knowledge about the Ag NP toxicity to different early development stages of B. glabrata contributes to its potential use as molluscicide and control of neglected tropical diseases, including schistosomiasis.

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Plant extracts can provide a viable alternative to controlling many crop pests. This study sought to assess the efficacy of vegetable extracts of the unripe fruits of Ilex paraguariensis (yerba maté) for chemical control of the channeled apple snail (Pomacea canaliculata) and of non-target species as the South American catfish (Rhamdia quelen) under laboratory conditions. In P. canaliculata, the LC50 of the decoction extract was 31.39 mg.L-1 and the LT50 was over 26 h. The LC50 of the butanol extract was 24.75 mg.L-1 and the LT50 was in the range of 28 to 32 h. In juvenile R. quelen, the LC50 of the decoction was 17.98 mg.L-1 and the LT50 was in the range of 10-12 h. These extracts are particularly attractive considering the source of compounds and their effectiveness as molluscicides.

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Abstract INTRODUCTION In Brazil, Biomphalaria glabrata, B. tenagophila, and B. straminea are intermediate hosts of Schistosoma mansoni, the etiological agent of schistosomiasis mansoni. Molluscicide use is recommended by the WHO for controlling the transmission of this parasite. Euphorbia milii latex has shown promising results as an alternative molluscicide. Thus, a natural molluscicide prototype kit based on freeze-dried E. milii latex was developed and evaluated against Biomphalaria spp. METHODS E. milii latex was collected, processed, and lyophilized. Two diluents were defined for freeze-dried latex rehydration, and a prototype kit, called MoluSchall, was produced. A stability test was conducted using prototype kits stored at different temperatures, and a toxicity assay was performed using Danio rerio. Additionally, MoluSchall was tested against B. glabrata under semi-natural conditions according to defined conditions in the laboratory. RESULTS MoluSchall was lethal to three Brazilian snail species while exhibiting low toxicity to D. rerio. Regardless of storage temperature, MoluSchall was stable for 24 months and was effective against B. glabrata under semi-natural conditions, with the same LD100 as observed under laboratory conditions. CONCLUSIONS MoluSchall is a natural, effective, and inexpensive molluscicide with lower environmental toxicity than existing molluscicides. Its production offers a possible alternative strategy for controlling S. mansoni transmission.

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In this study, the molluscicidal and antiparasitic activities of divaricatic acid was evaluated, targeting the mollusc Biomphalaria glabrata and cercariae of the helminth Schistosoma mansoni. Divaricatic acid showed high toxicity against both adult snails (5.5 µg/mL) and embryos (20 µg/mL after 6 h of exposure). Similar activity was observed in S. mansoni cercariae after only a short exposure time. The divaricatic acid proved to be a promising substance for the control of the snail B. glabrata, an intermediate host of schistosomiasis, as well as the cercariae of the pathogen.

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Subulina octona é um molusco terrestre com ampla distribuição no continente americano. É herbívoro, sendo encontrado em culturas agrícolas e jardins. Atua como hospedeiro intermediário de parasitos que acometem homens e animais, sendo considerado uma praga de interesse médico-veterinário e agrícola. O período de atividade é nos meses chuvosos e quentes, sendo seu comportamento com maior atividade no período noturno. Furcreae foetida é uma planta naturalizada que apresenta em seu metabolismo secundários saponinas esteroídicas que possuem atividade citotóxica seletiva. O uso de extratos vegetais tem sido motivo de pesquisas para o controle de moluscos pragas. Com isso, o objetivo deste estudo foi avaliar a influência do extrato de F. foetida no repertório comportamental e no horário de atividade de S. octona. Através do esmagamento por compressão das folhas de F. foetida obteve-se a seiva que foi filtrada e diluída em água destilada nas concentrações de 0,5 e 5%. Para verificar os efeitos do extrato de F. foetida no comportamento de S. octona utilizou-se 90 moluscos que foram divididos em 3 grupos: 1 controle e 2 tratados (T1 e T2 - 0,5 e 5% respectivamente). O extrato da seiva de F. foetida apresentou atividade de repelência e alterou o comportamento de S.octona. A análise química da seiva da planta foi realizada via marcha fitoquímica proposta por Matos (1988). O comportamento dos moluscos foi avaliado por meio de observações diretas pelos métodos grupo focal e scan. Para analisar se houve diferença significativa entre o horário de atividade utilizou-se o teste de Kruskall-Wallis e a frequência dos atos comportamentais foi avaliada pelo teste de comparação de amostras pareadas de Mann-Whitney, ambos com intervalo de confiança de 95%. Cada grupo foi composto por 10 indivíduos com três repetições. Foi possível perceber que a seiva alterou a frequência de realização do comportamento agregativo e deslocamento vertical, evidenciando sua ação repelente para S. octona.

Subulina octona is a terrestrial snail widely distributed in the Americas. It is a herbivore found in agricultural crops and gardens, able to acts as intermediate host of parasites that afflict humans and animals, being considered a pest of veterinary and agricultural interest. It is more active during rainy and hot months, speciallyat night. Furcreae foetida is a naturalized plant whose secondary metabolism produces steroidal saponins, which have selective cytotoxic activity. The use of plant extracts has been studied for control of snail pests. The objective of this study was to evaluate the influence of the sap of F. foetida on the behavioral repertoire and timing of activity of S. octona. Leaves of F. foetida were crushed to obtain the sap, which was filtered and diluted in distilled water at concentrations of 0.5 and 5%. To verify the effects of F. foetida sap on the behavior of S. octona, 90 snails were used, divided into three groups: one control group and two treated groups (T1 and T2 – 0.5 and 5% respectively). The extract of F. foetida sap presented repellent activity and altered the behavior of S. octona. The chemical analysis of the sap was performed by the phytochemical technique proposed by Matos (1988). The snails’ behavior was evaluated by direct observations by the focus group and scanning methods. To analyze the existence of significant differences in the timing of activity, the Kruskall-Wallis test was used, and the frequency of the behavioral acts was evaluated by the Mann-Whitney test of paired samples, both with confidence interval of 95%. Each group was composed of 10 individuals with three repetitions. The sap altered the frequency of aggregation behavior and vertical movement, indicating its repellent action on S. octona.

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Subulina octona é um molusco terrestre com ampla distribuição no continente americano. É herbívoro, sendo encontrado em culturas agrícolas e jardins. Atua como hospedeiro intermediário de parasitos que acometem homens e animais, sendo considerado uma praga de interesse médico-veterinário e agrícola. O período de atividade é nos meses chuvosos e quentes, sendo seu comportamento com maior atividade no período noturno. Furcreae foetida é uma planta naturalizada que apresenta em seu metabolismo secundários saponinas esteroídicas que possuem atividade citotóxica seletiva. O uso de extratos vegetais tem sido motivo de pesquisas para o controle de moluscos pragas. Com isso, o objetivo deste estudo foi avaliar a influência do extrato de F. foetida no repertório comportamental e no horário de atividade de S. octona. Através do esmagamento por compressão das folhas de F. foetida obteve-se a seiva que foi filtrada e diluída em água destilada nas concentrações de 0,5 e 5%. Para verificar os efeitos do extrato de F. foetida no comportamento de S. octona utilizou-se 90 moluscos que foram divididos em 3 grupos: 1 controle e 2 tratados (T1 e T2 - 0,5 e 5% respectivamente). O extrato da seiva de F. foetida apresentou atividade de repelência e alterou o comportamento de S.octona. A análise química da seiva da planta foi realizada via marcha fitoquímica proposta por Matos (1988). O comportamento dos moluscos foi avaliado por meio de observações diretas pelos métodos grupo focal e scan. Para analisar se houve diferença significativa entre o horário de atividade utilizou-se o teste de Kruskall-Wallis e a frequência dos atos comportamentais foi avaliada pelo teste de comparação de amostras pareadas de Mann-Whitney, ambos com intervalo de confiança de 95%. Cada grupo foi composto por 10 indivíduos com três repetições. Foi possível perceber que a seiva alterou a frequência de realização do comportamento agregativo e deslocamento vertical, evidenciando sua ação repelente para S. octona.(AU)

Subulina octona is a terrestrial snail widely distributed in the Americas. It is a herbivore found in agricultural crops and gardens, able to acts as intermediate host of parasites that afflict humans and animals, being considered a pest of veterinary and agricultural interest. It is more active during rainy and hot months, speciallyat night. Furcreae foetida is a naturalized plant whose secondary metabolism produces steroidal saponins, which have selective cytotoxic activity. The use of plant extracts has been studied for control of snail pests. The objective of this study was to evaluate the influence of the sap of F. foetida on the behavioral repertoire and timing of activity of S. octona. Leaves of F. foetida were crushed to obtain the sap, which was filtered and diluted in distilled water at concentrations of 0.5 and 5%. To verify the effects of F. foetida sap on the behavior of S. octona, 90 snails were used, divided into three groups: one control group and two treated groups (T1 and T2 0.5 and 5% respectively). The extract of F. foetida sap presented repellent activity and altered the behavior of S. octona. The chemical analysis of the sap was performed by the phytochemical technique proposed by Matos (1988). The snails behavior was evaluated by direct observations by the focus group and scanning methods. To analyze the existence of significant differences in the timing of activity, the Kruskall-Wallis test was used, and the frequency of the behavioral acts was evaluated by the Mann-Whitney test of paired samples, both with confidence interval of 95%. Each group was composed of 10 individuals with three repetitions. The sap altered the frequency of aggregation behavior and vertical movement, indicating its repellent action on S. octona.(AU)

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Subulina octona is a terrestrial mollusc found in gardens andplantations which may act as intermediate host for helminths and as vector for various pathogens. Furcraeafoetida is a naturalized plant, commonly used as ornament or as hedge. It has steroidal saponins on its secondarymetabolism, which are promising substances for mollusc control. The use of vegetal molluscicides has beenstudied for pest control since they are not as aggressive for both men and the environment and they may bea less toxic alternative for controlling these animals. This study aimed to analyze the influence of F. foetida onthe survival, growth and reproduction of S. octona. In order to assess the effect of the aqueous extract of thesap of F. foetida, the direct contact and indirect contact bioassays were used on S octona eggs, immatures andadults in laboratory conditions. Phytochemical analysis of F. foetida sap indicated presence of saponin in theleaves. The aqueous extract of F. foetida sap influenced on the survival and hatching of eggs in direct contact(without subtract) and indirect contact (with subtract); on the other hand, it had no influence on the growthor reproduction of S. octona. Immature and adult mortality rates were 100% in direct contact assays, and therewas significant difference for indirect contact assays regarding blank and negative control groups, which makesF. foetida sap a promising option for S. octona control.

Subulina octona é um molusco terrestre encontrado em jardins e culturas agrícolas, pode atuar comohospedeiro intermediário de helmintos e como vetor de vários patógenos. Furcraea foetida é uma planta naturalizada,muito usada para a ornamentação e cerca viva. Possui em seu metabolismo secundário saponinasesteroidais que são substâncias promissoras no controle de moluscos. O uso de moluscicidas de origem vegetaltem sido estudado para o controle de pragas, pois agridem menos o ambiente e ao homem, podendo ser uma alternativa menos tóxicas para o controle desses animais. O presente trabalho como objetivo avaliar a influênciade F. foetida sobre a sobrevivência, crescimento e reprodução de S. octona. Para avaliar o efeito do extratoaquoso da seiva de F. foetida, foram utilizados o teste de contato direto e contato indireto sobre ovos, jovense adultos de S. octona em condições de laboratório. A análise fitoquímica da seiva de F. foetida acusou a presençade saponina nas folhas. O extrato aquoso da seiva de F. foetida influenciou na sobrevivência e eclosão deovos no contato direto (sem substrato) e contato indireto (com substrato), por outro lado, não influenciou nocrescimento e na reprodução de S. octona. A mortalidade de jovens e adultos foi de 100% para os tratamentosdo experimento com contato direto e houve diferença significativa para os tratamentos do experimento comcontato indireto em relação ao controle branco e o negativo. Tornando a seiva de F. foetida, promissora para.

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RESUMO

Subulina octona is a terrestrial mollusc found in gardens andplantations which may act as intermediate host for helminths and as vector for various pathogens. Furcraeafoetida is a naturalized plant, commonly used as ornament or as hedge. It has steroidal saponins on its secondarymetabolism, which are promising substances for mollusc control. The use of vegetal molluscicides has beenstudied for pest control since they are not as aggressive for both men and the environment and they may bea less toxic alternative for controlling these animals. This study aimed to analyze the influence of F. foetida onthe survival, growth and reproduction of S. octona. In order to assess the effect of the aqueous extract of thesap of F. foetida, the direct contact and indirect contact bioassays were used on S octona eggs, immatures andadults in laboratory conditions. Phytochemical analysis of F. foetida sap indicated presence of saponin in theleaves. The aqueous extract of F. foetida sap influenced on the survival and hatching of eggs in direct contact(without subtract) and indirect contact (with subtract); on the other hand, it had no influence on the growthor reproduction of S. octona. Immature and adult mortality rates were 100% in direct contact assays, and therewas significant difference for indirect contact assays regarding blank and negative control groups, which makesF. foetida sap a promising option for S. octona control.(AU)

Subulina octona é um molusco terrestre encontrado em jardins e culturas agrícolas, pode atuar comohospedeiro intermediário de helmintos e como vetor de vários patógenos. Furcraea foetida é uma planta naturalizada,muito usada para a ornamentação e cerca viva. Possui em seu metabolismo secundário saponinasesteroidais que são substâncias promissoras no controle de moluscos. O uso de moluscicidas de origem vegetaltem sido estudado para o controle de pragas, pois agridem menos o ambiente e ao homem, podendo ser uma alternativa menos tóxicas para o controle desses animais. O presente trabalho como objetivo avaliar a influênciade F. foetida sobre a sobrevivência, crescimento e reprodução de S. octona. Para avaliar o efeito do extratoaquoso da seiva de F. foetida, foram utilizados o teste de contato direto e contato indireto sobre ovos, jovense adultos de S. octona em condições de laboratório. A análise fitoquímica da seiva de F. foetida acusou a presençade saponina nas folhas. O extrato aquoso da seiva de F. foetida influenciou na sobrevivência e eclosão deovos no contato direto (sem substrato) e contato indireto (com substrato), por outro lado, não influenciou nocrescimento e na reprodução de S. octona. A mortalidade de jovens e adultos foi de 100% para os tratamentosdo experimento com contato direto e houve diferença significativa para os tratamentos do experimento comcontato indireto em relação ao controle branco e o negativo. Tornando a seiva de F. foetida, promissora para. (AU)

Assuntos