Natural products as a control measure of the Achatina fulica (Gastropoda: Achatinidae) / Produtos naturais como medida de controle do molusco Achatina fulica (Gastropoda: Achatinidae)

Achatina fulica is a terrestrial mollusk known as the giant African snail that is related to environmental, economic, urban, and public health problems. As control measures for this mollusk, cooking salt (NaCl) and calcium oxide (CaO) are used, and baits are composed of metaldehyde. However, these measures have environmental toxicity and impact the soil. In this way, natural products have been tested on this mollusk to discover and develop a substance to combat this urban and agricultural pest. This article aims to evaluate studies involving natural products to control the population of Achatina fulica. Articles and works published in books were included in the present work. A total of 1,103 works were found during the search. Of these, 14 works met the objective of these review and were included in this article. The tests do not possess methodological standardization, do not have a maximum concentration to be considered active, or a maximum exposure time. A lack of standardization in the methodology of tests on A. fulica was observed. The performance of tests on other life stages of the mollusk, as well as tests that analyze other parameters, are essential. Only one article analyzed presented phytochemical analysis. No ecotoxicity tests were reported either. Some extracts showed promising results, highlighting the aqueous extract of Capsicum frutescens. More studies investigating the molluscicidal activity of natural products on A. fulica are needed. It is very relevant that the new studies present a phytochemical analysis of the tested extracts, as well as ecotoxicity studies.

Achatina fulica é um molusco terrestre conhecido como caramujo gigante africano que está relacionado a problemas ambientais, econômicos, urbanos e de saúde pública. Como medidas de controle para esse molusco, são utilizados sal de cozinha (NaCl) e óxido de cálcio (CaO), e as iscas são compostas de metaldeído. No entanto, essas medidas têm toxicidade ambiental e impactam o solo. Desta forma, produtos naturais foram testados neste molusco para descobrir e desenvolver uma substância para combater esta praga urbana e agrícola. Este artigo tem como objetivo avaliar estudos envolvendo produtos naturais para controle da população de Achatina fulica. Artigos e trabalhos publicados em livros foram incluídos no presente trabalho. Um total de 1.103 trabalhos foram encontrados durante a pesquisa. Destes, 14 trabalhos atendiam ao objetivo desta revisão e foram incluídos neste artigo. Os testes não possuem padronização metodológica, não possuem concentração máxima para serem considerados ativos ou tempo máximo de exposição. Observou-se uma falta de padronização na metodologia de testes em A. fulica. A realização de testes em outras fases da vida do molusco, bem como testes que analisem outros parâmetros, são essenciais. Apenas um artigo analisado apresentou análise fitoquímica. Também não foram relatados testes de ecotoxicidade. Alguns extratos apresentaram resultados promissores, com destaque para o extrato aquoso de Capsicum frutescens. Mais estudos investigando a atividade molusquicida de produtos naturais sobre A. fulica são necessários. É muito relevante que os novos estudos apresentem uma análise fitoquímica dos extratos testados, bem como estudos de ecotoxicidade.

Entomopathogenic Fungi-Mediated AgNPs: Synthesis and Insecticidal Effect against Plutella xylostella (Lepidoptera: Plutellidae).

The insect Plutella xylostella is known worldwide to cause severe damage to brassica plantations because of its resistance against several groups of chemicals and pesticides. Efforts have been conducted to overcome the barrier of P. xylostella genetic resistance. Because of their easy production and effective insecticidal activity against different insect orders, silver nanoparticles are proposed as an alternative for agricultural pest control. The use of entomopathogenic fungi for nanoparticle production may offer additional advantages since fungal biomolecules may synergistically improve the nanoparticle's effectiveness. The present study aimed to synthesize silver nanoparticles using aqueous extracts of Beauveria bassiana, Metarhizium anisopliae, and Isaria fumosorosea isolates and to evaluate their insecticidal activity against P. xylostella, as innovative nano-ecofriendly pest control. The produced silver nanoparticles were evaluated by measuring the UV-vis spectrum and the mean particle size by dynamic light scattering (DLS). I. fumosorosea aqueous extract with 3-mM silver nitrate solution showed the most promising results (86-nm mean diameter and 0.37 of polydispersity). Scanning electron microscopy showed spherical nanoparticles and Fourier-Transform Infrared Spectroscopy revealed the presence of amine and amide groups, possibly responsible for nanoparticles' reduction and stabilization. The CL50 value of 0.691 mg mL-1 was determined at 72-h for the second-instar larvae of the P. xylostella, promoting a 78% of cumulative mortality rate after the entire larval stage. From our results, the synthesis of silver nanoparticles mediated by entomopathogenic fungi was successful in obtaining an efficient product for insect pest control. The I. fumosorosea was the most suitable isolate for the synthesis of silver nanoparticles contributing to the development of a green nanoproduct and the potential control of P. xylostella.

Nanoparticles Loaded with Essential Oil from Zanthoxylum riedelianum Engl. Leaves: Characterization and Effects on Bemisia tabaci Middle-East Asia Minor 1.

Bemisia tabaci (Gennadius) (Hemiptera: Aleyrodidae) Middle-East Asia Minor 1 is a major pest of agricultural production systems. It is controlled by synthetic insecticides. Essential oils are promising eco-friendly alternatives. This study developed and characterized nanoparticles loaded with essential oils of Zanthoxylum riedelianum Engl. (Rutaceae) leaves and evaluated their potential for B. tabaci management. The essential oil exhibited an average yield of 0.02% (w w-1) and showed as major components γ-elemene (24.81%), phytol (18.16%), bicyclogermacrene (16.18%), cis-nerolidol (8.26%), and D-germacrene (6.52%). Characterization of the nanoparticles showed a pH between 4.5 and 6.7, a zeta potential of approximately - 25 mV, particle-size distribution ranging from 450 to 550 nm, and encapsulation efficiency close to 98%. The nanoencapsulation was an efficient process that provided photostability against photodegradation. Bioassays with crude and nanoencapsulated essential oils significantly reduced the number of nymphs and eggs of B. tabaci, with the best results observed at concentrations of 5 and 2% (v v-1). Our results demonstrated that essential oils from Z. riedelianum can be nanoformulated resulting in a stable product while maintaining their biological activity against B. tabaci Middle-East Asia Minor 1.

Identification and recombinant expression of an antimicrobial peptide (cecropin B-like) from soybean pest Anticarsia gemmatalis.

BACKGROUND: Insects can be found in numerous diverse environments, being exposed to pathogenic organisms like fungi and bacteria. Once these pathogens cross insect physical barriers, the innate immune system operates through cellular and humoral responses. Antimicrobial peptides are small molecules produced by immune signaling cascades that develop an important and generalist role in insect defenses against a variety of microorganisms. In the present work, a cecropin B-like peptide (AgCecropB) sequence was identified in the velvetbean caterpillar Anticarsia gemmatalis and cloned in a bacterial plasmid vector for further heterologous expression and antimicrobial tests. METHODS: AgCecropB sequence (without the signal peptide) was cloned in the plasmid vector pET-M30-MBP and expressed in the Escherichia coli BL21(DE3) expression host. Expression was induced with IPTG and a recombinant peptide was purified using two affinity chromatography steps with Histrap column. The purified peptide was submitted to high-resolution mass spectrometry (HRMS) and structural analyses. Antimicrobial tests were performed using gram-positive (Bacillus thuringiensis) and gram-negative (Burkholderia kururiensis and E. coli) bacteria. RESULTS: AgCecropB was expressed in E. coli BL21 (DE3) at 28°C with IPTG 0.5 mM. The recombinant peptide was purified and enriched after purification steps. HRMS confirmed AgCrecropB molecular mass (4.6 kDa) and circular dichroism assay showed α-helix structure in the presence of SDS. AgCrecropB inhibited almost 50% of gram-positive B. thuringiensis bacteria growth. CONCLUSIONS: The first cecropin B-like peptide was described in A. gemmatalis and a recombinant peptide was expressed using a bacterial platform. Data confirmed tertiary structure as predicted for the cecropin peptide family. AgCecropB was capable to inhibit B. thuringiensis growth in vitro.

Temperature-dependent development models describing the effects of temperature on the development of Spodoptera eridania.

BACKGROUND: The southern armyworm, Spodoptera eridania, is a polyphagous species native to the American tropics that recently invaded Africa. Knowledge of the impact of temperature on its development and survival is important to understand the risks of this species spreading to other regions and to develop phenological models for pest management. This study evaluated the effects of temperature on the development and survival of S. eridania and selected mathematical models to simulate its development. RESULTS: The southern armyworm completed its development between 15 and 32 °C, but eggs did not hatch at 34 °C. Lower survival and higher rates of deformities in adults were recorded at 15 and 32 °C. Among the ten mathematical models evaluated, Briere-2, Lactin-2 and Shi were considered suitable for describing the temperature-dependent development rate of S. eridania. The lower thermal threshold estimated by these models for the egg to adult life cycle ranged from 10.8 to 12.1 °C, whereas the upper threshold ranged between 33.9 and 35.0 °C. CONCLUSIONS: The southern armyworm can develop within a wide range of temperatures, which partially explains its wide distribution in regions with different climatic conditions, and demonstrates its potential to occur in regions outside its native range. Our findings can be employed in the development of management strategies using the selected models to predict the occurrence of S. eridania in the field and determine the most effective times to implement control measures.

Identification and recombinant expression of an antimicrobial peptide (cecropin B-like) from soybean pest Anticarsia gemmatalis

Insects can be found in numerous diverse environments, being exposed to pathogenic organisms like fungi and bacteria. Once these pathogens cross insect physical barriers, the innate immune system operates through cellular and humoral responses. Antimicrobial peptides are small molecules produced by immune signaling cascades that develop an important and generalist role in insect defenses against a variety of microorganisms. In the present work, a cecropin B-like peptide (AgCecropB) sequence was identified in the velvetbean caterpillar Anticarsia gemmatalis and cloned in a bacterial plasmid vector for further heterologous expression and antimicrobial tests. Methods AgCecropB sequence (without the signal peptide) was cloned in the plasmid vector pET-M30-MBP and expressed in the Escherichia coli BL21(DE3) expression host. Expression was induced with IPTG and a recombinant peptide was purified using two affinity chromatography steps with Histrap column. The purified peptide was submitted to high-resolution mass spectrometry (HRMS) and structural analyses. Antimicrobial tests were performed using gram-positive (Bacillus thuringiensis) and gram-negative (Burkholderia kururiensis and E. coli) bacteria. Results AgCecropB was expressed in E. coli BL21 (DE3) at 28°C with IPTG 0.5 mM. The recombinant peptide was purified and enriched after purification steps. HRMS confirmed AgCrecropB molecular mass (4.6 kDa) and circular dichroism assay showed α-helix structure in the presence of SDS. AgCrecropB inhibited almost 50% of gram-positive B. thuringiensis bacteria growth. Conclusions The first cecropin B-like peptide was described in A. gemmatalis and a recombinant peptide was expressed using a bacterial platform. Data confirmed tertiary structure as predicted for the cecropin peptide family. AgCecropB was capable to inhibit B. thuringiensis growth in vitro.(AU)

Identification and recombinant expression of an antimicrobial peptide (cecropin B-like) from soybean pest Anticarsia gemmatalis

Insects can be found in numerous diverse environments, being exposed to pathogenic organisms like fungi and bacteria. Once these pathogens cross insect physical barriers, the innate immune system operates through cellular and humoral responses. Antimicrobial peptides are small molecules produced by immune signaling cascades that develop an important and generalist role in insect defenses against a variety of microorganisms. In the present work, a cecropin B-like peptide (AgCecropB) sequence was identified in the velvetbean caterpillar Anticarsia gemmatalis and cloned in a bacterial plasmid vector for further heterologous expression and antimicrobial tests. Methods AgCecropB sequence (without the signal peptide) was cloned in the plasmid vector pET-M30-MBP and expressed in the Escherichia coli BL21(DE3) expression host. Expression was induced with IPTG and a recombinant peptide was purified using two affinity chromatography steps with Histrap column. The purified peptide was submitted to high-resolution mass spectrometry (HRMS) and structural analyses. Antimicrobial tests were performed using gram-positive (Bacillus thuringiensis) and gram-negative (Burkholderia kururiensis and E. coli) bacteria. Results AgCecropB was expressed in E. coli BL21 (DE3) at 28°C with IPTG 0.5 mM. The recombinant peptide was purified and enriched after purification steps. HRMS confirmed AgCrecropB molecular mass (4.6 kDa) and circular dichroism assay showed α-helix structure in the presence of SDS. AgCrecropB inhibited almost 50% of gram-positive B. thuringiensis bacteria growth. Conclusions The first cecropin B-like peptide was described in A. gemmatalis and a recombinant peptide was expressed using a bacterial platform. Data confirmed tertiary structure as predicted for the cecropin peptide family. AgCecropB was capable to inhibit B. thuringiensis growth in vitro.(AU)

Genetic variants in Argentinean isolates of Spodoptera frugiperda Multiple Nucleopolyhedrovirus.

The fall armyworm, Spodoptera frugiperda (JE Smith) is a key pest in the Americas. Control strategies are mainly carried out by use of chemical insecticides and transgenic crops expressing Bacillus thuringiensis toxins. In the last years, resistance of S. frugiperda populations to transgenic corn was reported in different Latin American countries. The baculovirus Spodoptera frugiperda Multiple Nucleopolyhedrovirus (SfMNPV) is a pathogenic agent for the fall armyworm and a potential alternative for its control in integrated pest management strategies. In this work, we analyze some characteristics of two baculovirus isolates collected from maize (SfMNPV-M) and cotton (SfMNPV-C) fields from Argentina. The isolates were compared by restriction enzymes patterns and the analysis reveals the presence of genotypic variants in the SfMNPV-M isolate. We confirmed a deletion by sequencing fragments encompassing egt gene and most part of its contiguous gene (orf A) in a SfMNVP-M genotypic variant. Additionally, we estimated the 50% lethal dose and median survival time of each isolate in bioassays with S. frugiperda larvae.

Identificación de un aislamiento argentino de Spodoptera frugiperda granulovirus / Identification of an Argentinean isolate of Spodoptera frugiperda granulovirus

Abstract The fall armyworm, Spodoptera frugiperda (J.E. Smith) (Lepidoptera: Noctuidae), is an important maize pest. Due to the environmental impact and emergence of resistance caused by chemical pesticides and transgenic events, the use of baculoviruses becomes a safe and useful alternative for its control in integrated pest management strategies. Here we report the identification of a novel isolate of a granulovirus of S. frugiperda native to the central region of Argentina, named SfGV ARG. We observed that larvae infected with SfGV ARG showed a yellowish coloration, swollen body and, in some cases, severe lesions in the last abdominal segments. We confirmed the identity of the isolate by sequencing fragments of the lef-8, lef-9 and granulin genes and by calculating evolutionary distances using the Kimura-2-Parameter model. SfGV ARG DNA restriction pattern allowed to estimate a genome of at least 135 kb.

Resumen La oruga militar tardía, Spodoptera frugiperda (J.E. Smith) (Lepidoptera: Noctuidae), es una plaga importante del maíz. Debido al impacto ambiental y a la aparición de resistencia causados por los pesticidas químicos y los eventos transgénicos, el uso de baculovirus resulta una alternativa útil y saludable para su control en estrategias de manejo integrado de plagas. En este trabajo reportamos la identificación de un nuevo aislamiento del granulovirus de la S. frugiperda nativo de la región central de Argentina, SfGV ARG. Se observó que larvas infectadas con SfGV ARG mostraron coloración amarillenta, hinchazón y, en algunos casos, lesiones graves en los últimos segmentos abdominales. Se confirmó la identidad del aislamiento por secuenciación de fragmentos de los genes lef-8, lef-9y granulina, y por cálculo de distancias evolutivas usando el parámetro de Kimura-2. El patrón de restricción generado con el ADN genómico de SfGV ARG permitió estimar un tamaño de genoma de al menos 135 kb.

Effects of semi-purified fractions from stems of Clusia hilariana on the development of Dysdercus peruvianus

ABSTRACT Plants represent a huge source of substances, with pharmacological potential. Brazil has a diversity of agricultural insect pests and an urgent need for safer methods of insect control. Dysdercus peruvianus (Guerin-Meneville, 1831), Pyrrhocoridae, is an economically important species of the Order Hemiptera and a pest of cotton (Gossypium hirsutum L., Malvaceae). Secondary metabolites in stems of Clusia hilariana Schltdl., Clusiaceae, such as terpenes and benzophenones, have been reported to be insecticidal. The present study investigated the effects of semi-purified fractions of hexane crude extracts from male C. hilariana stems on development of D. peruvianus. Biological parameters at different stages of development including body malformations, range of molting period and toxicity were evaluated. Most insects died and failed to develop due to attachment of their exuviae to the abdomen. Deformations of wings and defective tarsi also occurred. The secondary metabolites from semi-purified fractions of C. hilariana caused mortality, interference in molting and metamorphosis, and body deformations, probably by interacting with the neuroendocrine system. The results demonstrate the potential of C. hilariana extracts as an alternative for the control of the phytophagous insect D. peruvianus and for the development of environmentally safe and biodegradable bio insecticides.

Isolation and Characterization of Microsatellite Markers for Soybean Looper (Lepidoptera: Noctuidae).

We constructed 13 microsatellite markers for Chrysodeixis includens (Walker), a serious crop pest in the Americas. All SSR (Simple Sequence Repeat) markers were polymorphic, with no evidence of linkage disequilibrium between any loci in any population. The total number of alleles per locus ranged from 5 for L3, L9, and L11 to 26 for L6; the mean number of alleles per locus in three populations of C. includens ranged from 2.33 for L3 to 14.67 for L6. Hardy-Weinberg equilibrium (HWE) deviation was not observed in four loci for at least one population (L3, L5, L9, L10). Markers L6, L7, L8, L10, L11, L12, and L13 showed a frequency of null alleles > 0.2 for at least one population. STRUCTURE and F-statistics revealed low population structure among the populations (FST = 0.013) and a high degree of inbreeding (FIS = 0.658). The SSR markers developed here will be useful in future studies on the ecology, demography, host dynamics, and gene flow of C. includens. This information is essential to understand the recent status of C. includens as a key pest in South America.

Range-wide population genomics of the Mexican fruit fly: Toward development of pathway analysis tools.

Recurrently invading pests provide unique challenges for pest management, but also present opportunities to utilize genomics to understand invasion dynamics and inform regulatory management through pathway analysis. In the southern United States, the Mexican fruit fly Anastrepha ludens is such a pest, and its incursions into Texas and California represent major threats to the agricultural systems of those regions. We developed a draft genome assembly for A. ludens, conducted range-wide population genomics using restriction site-associated DNA sequencing, and then developed and demonstrated a panel of highly differentiated diagnostic SNPs for source determination of intercepted flies in this system. Using 2,081 genomewide SNPs, we identified four populations across the range of A. ludens, corresponding to western Mexico, eastern Mexico/Texas, Guatemala/Belize/Honduras, and Costa Rica/Panama, with some intergradation present between clusters, particularly in Central America. From this population genomics framework, we developed a diagnostic panel of 28 highly differentiated SNPs that were able to recreate the genomewide population structure in this species. We demonstrated this panel on a set of test specimens, including specimens intercepted as part of regular trapping surveillance in Texas and California, and we were able to predict populations of origin for these specimens. This methodology presents a highly applied use of genomic techniques and can be implemented in any group of recurrently invading pests.

Identification of an Argentinean isolate of Spodoptera frugiperda granulovirus.

The fall armyworm, Spodoptera frugiperda (J.E. Smith) (Lepidoptera: Noctuidae), is an important maize pest. Due to the environmental impact and emergence of resistance caused by chemical pesticides and transgenic events, the use of baculoviruses becomes a safe and useful alternative for its control in integrated pest management strategies. Here we report the identification of a novel isolate of a granulovirus of S. frugiperda native to the central region of Argentina, named SfGV ARG. We observed that larvae infected with SfGV ARG showed a yellowish coloration, swollen body and, in some cases, severe lesions in the last abdominal segments. We confirmed the identity of the isolate by sequencing fragments of the lef-8, lef-9 and granulin genes and by calculating evolutionary distances using the Kimura-2-Parameter model. SfGV ARG DNA restriction pattern allowed to estimate a genome of at least 135 kb.

Influência de Furcraea foetida (L.) Haw. no comportamento de Subulina octona (Bruguière, 1789) (Mollusca, Subulinidae) / Influence of Furcraea foetida (L.) Haw. on the behaviour of Subulina octona (Bruguière, 1789) (Mollusca, Subulinidae)

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)

Influência de Furcraea foetida (L.) Haw. no comportamento de Subulina octona (Bruguière, 1789) (Mollusca, Subulinidae) / Influence of Furcraea foetida (L.) Haw. on the behaviour of Subulina octona (Bruguière, 1789) (Mollusca, Subulinidae)

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.

Morphological Characterization of Helicoverpa armigera (Hübner) (Lepidoptera: Noctuidae: Heliothinae).

The cotton bollworm Helicoverpa armigera (Hübner) is a widespread lepidopteran pest found in various crops worldwide. This highly polyphagous species, commonly found both in the Old and New World, has caused significant economic damage as an invasive agricultural pest in Brazil since 2013. The goal of the present study is to provide a detailed morphological assessment of adults and immature stages of H. armigera, as this species is often confused with H. zea (Boddie), a congeneric species that is native to the New World. The biology data were acquired during four full life cycles, and observations on general behavior, nocturnal habits of larvae and adults, and sensitivity of larvae to humidity were recorded. Larval chaetotaxy differs between the first and the remaining instars, which bear L2 on the meso- and metathorax and L3 on A3 through A6, along with conspicuous chalazae and longitudinal bands. Important morphological characters of this species include the following: eggs with four micropylar openings, lined with 12 cells arranged in the shape of a rosette; pupa adecticous and obtect, with prominent spiracles; adults with the distal antennomere striate. Adults exhibit sexual dimorphism in the number of setae on the frenulum and spines on the prothoracic leg. Illustrations of the critical morphological features of this species are provided.

Checklist and description of three new chromatic patterns of Pachycoris torridus (Scopoli, 1772) (Hemiptera: Scutelleridae)

In the present paper, 27 chromatic patterns of the specie Pachycoris torridus (Scopoli, 1772) were grouped and three new patterns are described. Because of this high phenotypic polymorphism, P. torridus already been registered eight times as a new specie, highlighting the importance of the application of different tools to assist in taxonomy of this hemipterous of economic importance.

No presente artigo, 27 padro˜ es croma´ ticos da espe´cie Pachycoris torridus (Scopoli, 1772) sa˜o agrupados e treˆs novos padro˜ es sa˜o descritos. Devido a esse grande polimorfismo fenoti´pico, P. torridus ja´ foi registrado oito vezes como espe´cie nova, o que ressalta a importaˆncia da aplicac¸a˜o de diferentes ferramentas para auxiliar na taxonomia desse hemi´ptero de importaˆncia econoˆmica.

Desarrollo post-embrionario, fecundidad y consumo de alimento de Dichroplus exilis (Orthoptera: Acrididae) bajo condiciones controladas

Postembryonic development, fecundity and food consumption of Dichroplus exilis (Orthoptera: Acrididae) under controlled conditions. Dichroplus exilis is a widely distributed species in Southern South America. Although there have been reports of D. exilis as an agricultural pest, some recent observations suggest that the damage attributed to D. elongatus may actually have been caused by D. exilis. This study was conducted to determine the postembryonic life cycle stages, fertility and food consumption of this species under controlled conditions (30°C, 14L-10D, 40% RH).Individuals employed belong to the laboratory-hatched first generation (F1), from adults (n=64, ♀=28, ♂=36) collected in natural grasslands near Rafaela, Santa Fe province in North- Eastern Argentina. Three cohorts of 16, 17 and 20 individuals were monitored independently in acetate tubes on a daily basis, until death of the last insect. Average fecundity was 381.84, 38.54 eggs per female. Egg-pod incubation time was 14.4, 1.08 days and six nymphal instars were recorded. Nymphal development time was 41.38, 0.71 days (I=8.73, 0.20; II=6.38, 0.24; III=5.64, 0.33; IV=7.15; 0.43; V=9.76, 0.54; IV=7.85, 0.95). The recorded food consumption was 9.89, 1.08 (mg/ind/day) for nymphs IV, 18.04, 0.73 (mg/ind/day) for nymphs V-IV, 16.76, 1.06 (mg/ind/day) for pre-reproductive males, 28.09, 1.81 (mg/ind/day) for pre-reproductive females, 7.71, 0.91 (mg/ind/day) for reproductive males and 13.06, 0.71 (mg/ind/day) for reproductive females, while the average adult food consumption, regardless of sex and reproductive status, was 16.41, 4.32mg/day. Average food consumption of adult females was 17.47, 1.15mg, and was significantly higher than that of males (10.83, 0.91mg). Data obtained in this study showed that D. exilis exhibits at least some of the biological attributes needed to configure an actual or potential agricultural pest, albeit not yet recognized as such. Field monitoring ...

La Subfamilia Melanoplinae tiene una relevancia central dentro de la acridiofauna Argentina. Varias especies suelen ser numéricamente dominantes en las comunidades de acridios del país y algunas constituyen serias plagas. El objetivo de este trabajo fue conocer el ciclo de vida postembrionario, la fecundidad y supervivencia de las hembras y el consumo de alimento de Dichruplus exilis bajo condiciones controladas (30°C; 40%HR y 14L-10O). Para ello se realizó el seguimiento de tres cohortes de 16, 17 y 20 individuos. El tiempo de incubación fue de 14.4±1.08 días. La duración del desarrollo ninfal fue 41.38; 0.71 días (I 8.73; 0.20, II 6.38; 0.24, III 5.64; 0.33, IV 7.15; 0.43, V 9.76; 0.54; IV 7.85; 0.95); la fecundidad promedio fue de 381.84, 38.54huevos/hembra. El consumo registrado fue de 9.89; 1.08 (mg/ind./día) para las ninfas de IV, 18.04; 0.73 (mg/ind./día) para las de V y IV, mientras que el consumo promedio de los adultos, sin diferenciar sexo y estado reproductivo, fue de 16.41; 4.32mg/día. Estos parámetros, al ser comparados con los de otras especies afines, indican que D. exilis exhibe atributos biológicos que condicen con los de otros melanoplinos considerados plaga.

Biologia de Anticarsia gemmatalis Hübner, 1818 (Lepidoptera: Noctuidae) na cultura da soja

The biology of Anticarsia gemmatalis (Lepidoptera:Noctuidae) was studied in soybean fields. The experiments were conducted during the seasons of 1992 through 1997. Two evaluations were performed each year with 20 replications for each phase of A. gemmatalis. The insects taken to the field were reared in laboratory for two generations on leaves of the host soybean variety, at 27 ± 1 oC, 14 - hour photophase, and 60 ± 10 % RH, up to the pupal phase. The number, viability and period of incubation of the eggs as well as the viability of the larval and pupal stages, longevity of adults, egg-laying rhythm, and sexual rate were determined. The mean viability for the egg stage ranged from 43.0% (1996) to 76.3 % (1997), with an average duration of 3.60 days. The larval period of individuals originating females varied from 8.95 (1993) to 16.75 days (1997) and the mean viability was 17.2 %. The female and male pupal periods was nearly the same during the surveyed years (9.80 and 10.61 days, respectively). Female adult longevity varied from 9.10 (1997) to 12.90 days (1996). The mean eggs oviposited were 73.5, with viability of 42.3 %. The mean sexual rate was 0.50. Egg laying, occurred between the 7th (1997) or 13th day (1996), peaking on the 2nd day. The mean female cycle (egg - adult) was 26.51 days.

Estudou-se a biologia de Anticarsia gemmatalis (Lepidoptera: Noctuidae) em campos de soja. Os experimentos foram conduzidos durante os períodos agrícolas de 1992 a 1997. Em cada ano foram realizadas duas avaliações, com 20 repetições para cada fase do ciclo de A. gemmatalis. Os insetos levados ao campo foram criados por duas gerações, em laboratório, sobre folhas de soja da variedade hospedeira à temperatura de 27 ± 1 oC, fotofase de 14 horas e 60 ± 10 % UR até a fase de pupa. Foram determinados o número, viabilidade e período de incubação de ovos e viabilidade das fases larval e pupal, longevidade dos adultos, ritmo de postura e razão sexual. A viabilidade média para a fase de ovo variou de 43,0 % (1996) a 76,3 % (1997), sendo a duração média de 3,60 dias. O período larval dos indivíduos que originaram fêmeas variou de 8,95 (1993) a 16,75 dias (1997) e a viabilidade média foi de 17,2 %. O períCodo de pupas fêmeas e de machos foi praticamente o mesmo nos anos estudados (9,80 e 10,61 dias, respectivamente). A longevidade dos adultos fêmeas variou entre 9,10 (1997) a 12,90 dias (1996). A média de ovos colocados foi de 73,5, dos quais 42,3 % viáveis. A razão sexual média foi de 0,50. O período de postura, ocorreu até o 7o (1997) ou 13o dias (1996) com o acme no 2o dia. O ciclo médio de vida da fêmea (ovo - adulto) foi de 26,51 dias.

Biologia de Anticarsia gemmatalis Hübner, 1818 (Lepidoptera: Noctuidae) na cultura da soja

The biology of Anticarsia gemmatalis (Lepidoptera:Noctuidae) was studied in soybean fields. The experiments were conducted during the seasons of 1992 through 1997. Two evaluations were performed each year with 20 replications for each phase of A. gemmatalis. The insects taken to the field were reared in laboratory for two generations on leaves of the host soybean variety, at 27 ± 1 oC, 14 - hour photophase, and 60 ± 10 % RH, up to the pupal phase. The number, viability and period of incubation of the eggs as well as the viability of the larval and pupal stages, longevity of adults, egg-laying rhythm, and sexual rate were determined. The mean viability for the egg stage ranged from 43.0% (1996) to 76.3 % (1997), with an average duration of 3.60 days. The larval period of individuals originating females varied from 8.95 (1993) to 16.75 days (1997) and the mean viability was 17.2 %. The female and male pupal periods was nearly the same during the surveyed years (9.80 and 10.61 days, respectively). Female adult longevity varied from 9.10 (1997) to 12.90 days (1996). The mean eggs oviposited were 73.5, with viability of 42.3 %. The mean sexual rate was 0.50. Egg laying, occurred between the 7th (1997) or 13th day (1996), peaking on the 2nd day. The mean female cycle (egg - adult) was 26.51 days.

Estudou-se a biologia de Anticarsia gemmatalis (Lepidoptera: Noctuidae) em campos de soja. Os experimentos foram conduzidos durante os períodos agrícolas de 1992 a 1997. Em cada ano foram realizadas duas avaliações, com 20 repetições para cada fase do ciclo de A. gemmatalis. Os insetos levados ao campo foram criados por duas gerações, em laboratório, sobre folhas de soja da variedade hospedeira à temperatura de 27 ± 1 oC, fotofase de 14 horas e 60 ± 10 % UR até a fase de pupa. Foram determinados o número, viabilidade e período de incubação de ovos e viabilidade das fases larval e pupal, longevidade dos adultos, ritmo de postura e razão sexual. A viabilidade média para a fase de ovo variou de 43,0 % (1996) a 76,3 % (1997), sendo a duração média de 3,60 dias. O período larval dos indivíduos que originaram fêmeas variou de 8,95 (1993) a 16,75 dias (1997) e a viabilidade média foi de 17,2 %. O períCodo de pupas fêmeas e de machos foi praticamente o mesmo nos anos estudados (9,80 e 10,61 dias, respectivamente). A longevidade dos adultos fêmeas variou entre 9,10 (1997) a 12,90 dias (1996). A média de ovos colocados foi de 73,5, dos quais 42,3 % viáveis. A razão sexual média foi de 0,50. O período de postura, ocorreu até o 7o (1997) ou 13o dias (1996) com o acme no 2o dia. O ciclo médio de vida da fêmea (ovo - adulto) foi de 26,51 dias.