RESUMEN
The mango weevil, Sternochetus mangiferae (Fabricius) (Curculionidae), pest present in Brazil and is restricted to some municipalities in the Rio de Janeiro State. This curculionid attacks the mango crop exclusively and puts mango production globally at risk, especially those destined for export. Using ecological modeling tools, this study is the first to map the potential risk of S. mangiferae in Brazil. We aimed to identify the potential distribution of this pest in Brazilian states, drawing up thematic maps of regions that present suitable and unsuitable climatic conditions for the establishment of the pest using the MaxEnt ecological niche model. The average annual temperature, the annual precipitation, the average daytime temperature range, and the annual temperature range were the variables that contributed most to the selected model. The MaxEnt model predicted highly suitable areas for S. mangiferae throughout the Brazilian coast, especially on the northeast coast. The region responsible for more than 50% of mango production in Brazil, the São Francisco Valley, was classified by the model with suitability for the pest; it can impacts exportations due to the imposition of phytosanitary barriers. This information can be used in strategies to prevent the introduction and establishment of this pest in new areas and monitor programs in areas with recent occurrence. In addition, the model results can be used in future research plans on S. mangiferae in worldwide modeling studies and climate change scenarios.
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The beetle Anthonomus grandis Boheman, 1843, is the main cotton pest, causing enormous losses in cotton. The breeding of genetically modified plants with A. grandis resistance is seen as an important control strategy. However, the identification of molecules with high toxicity to this insect remains a challenge. The susceptibility of A. grandis larvae to proteins (Cry1Ba, Cry7Ab, and Mpp23Aa/Xpp37Aa) from Bacillus thuringiensis Berliner, 1915, with toxicity reported against Coleopteran, has been evaluated. The ingestion of different protein concentrations (which were incorporated into an artificial diet) by the larvae was tested in the laboratory, and mortality was evaluated after one week. All Cry proteins tested exhibited higher toxicity than that the untreated artificial diet. These Cry proteins showed similar results to the control Cry1Ac, with low toxicity to A. grandis, since it killed less than 50% of larvae, even at the highest concentration applied (100 µg·g-1). Mpp/Xpp proteins provided the highest toxicity with a 0.18 µg·g-1 value for the 50% lethal concentration. Importantly, this parameter is the lowest ever reported for this insect species tested with B. thuringiensis proteins. This result highlights the potential of Mpp23Aa/Xpp37Aa for the development of a biotechnological tool aiming at the field control of A. grandis.
Asunto(s)
Bacillaceae , Bacillales , Bacillus thuringiensis , Escarabajos , Insecticidas , Gorgojos , Animales , Larva , Bacillus thuringiensis/genética , Bacillus thuringiensis/metabolismo , Insecticidas/toxicidad , Insecticidas/metabolismo , Fitomejoramiento , GossypiumRESUMEN
Etofenprox is a novel pyrethroid insecticide that targets the nervous system of insects by affecting the function of the sodium channel. The current study examines the insecticidal activity of etofenprox against Ephestia kuehniella (Lepidoptera: Pyralidae) larvae, Rhyzopertha dominica (Coleoptera: Bostrychidae) adults, Sitophilus oryzae (Coleoptera: Curculionidae) adults, and Tribolium confusum (Coleoptera: Tenebrionidae) adults and larvae on different grain commodities. For this purpose, etofenprox was applied on barley, maize, oats, rice, and wheat at 0.1, 1, 5, and 10 ppm. Mortality levels were recorded after 7, 14, and 21 days of exposure. For E. kuehniella larvae, 10 ppm applied on whole rice killed 96.1% of the exposed individuals after 21 days of exposure. The application of etofenprox on oats at 5 ppm caused the death of 98.3% of the exposed R. dominica adults. Complete mortality was observed for R. dominica adults 21 days post-exposure to oats and whole rice treated with 10 ppm etofenprox. The highest concentration applied on barley caused 95.0% mortality to S. oryzae adults, while the same concentration on maize killed 76.8% of T. confusum adults after 21 days of exposure. Larvae of T. confusum exhibited high mortality levels reaching 99.4% after 21 days of exposure to barley treated with 10 ppm etofenprox. Progeny production of parental R. dominica adults was almost suppressed on all commodities treated with 5 ppm etofenprox. The offspring emergence of S. oryzae ranged between 4.4 and 24.6 adults per vial at 10 ppm. No T. confusum progeny was produced at 10 ppm etofenprox. Our results document that etofenprox is highly effective as grain protectant against several insect species, their developmental stages and their progeny production, but its performance depends on the type of the commodity that it is applied on.
Asunto(s)
Escarabajos , Hordeum , Insecticidas , Mariposas Nocturnas , Oryza , Piretrinas , Tribolium , Gorgojos , Humanos , Animales , Triticum , Avena , Zea mays , Dominica , Grano Comestible , InsectosRESUMEN
The boll weevil (Anthonomus grandis Boheman) reproduces on a reported 13 species of wild host plants in North America, two in the United States and 12 in Mexico. The distributions of these plants are of economic importance to pest management and provide insight into the evolutionary history and origin of the BW. However, detailed information regarding the distributions of many of these species is lacking. In this article, we present distribution models for all of the reported significant BW host plants from Mexico and the United States using spatial distribution modelling software. Host plant distributions were divided into two groups: "eastern" and "western." In Mexico, Hampea nutricia along the Gulf Coast was the most important of the eastern group, and the wild cottons, Gossypium aridum and Gossypium thurberi were most important in the western group. Other species of Hampea, Gossypium, and Cienfuegosia rosei have relatively restricted distributions and are of apparent minimal economic importance. Cienfuegosia drummondii is the only truly wild host in the southern United States, east of New Mexico. Factors determining potential distributions were variable and indicated that species were present in five vegetation types. Ecological and economic considerations of host plant distributions are discussed, as well as threats to host plant conservation.
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With approximately 83,000 species described, Curculionidae is the largest family of beetles, comprising more than 80% of all weevil species worldwide. Many species of Curculionidae attack a wide range of native and orchards crops, as well as globally important stored products such as grains, flour, and seeds, being responsible for significant environmental and economic losses. This work provides an overview of the research in the identification of aggregation pheromones of Curculionidae, and their potential contributions to the development of semiochemical-based pest management strategies. The synergistic effect of the host plant volatiles in the attractiveness of weevil pheromones is also briefly reported, demonstrating the important role of these additional attractants in the chemical communication of curculionids.
Asunto(s)
Control de Insectos , Control Biológico de Vectores , Feromonas/farmacología , Gorgojos , AnimalesRESUMEN
The genus Isodacrys Sharp, 1911 is revised. Twenty species of the genus are recognized ranging from south United States of America, Mexico, Guatemala and Honduras of which eight are herein described as new. These species are Isodacrys antrum Cortés-Hernández, new species (Mexico: Tamaulipas, Chiapas; Guatemala: Baja Verapaz); Isodacrys carlae Cortés-Hernández, new species (Mexico: Coahuila, Hidalgo, Nuevo León, San Luis Potosí, Tamaulipas); Isodacrys confusum Cortés-Hernández, new species (Mexico: Tamaulipas); Isodacrys fasciatum Cortés-Hernández, new species (Mexico: Coahuila, Durango, Nuevo León); Isodacrys frontalis Cortés-Hernández, new species (Mexico: Oaxaca; Guatemala: Sacatepéquez, Guatemala); Isodacrys kuchii Cortés-Hernández, new species (Mexico: Puebla); Isodacrys obrienorum Cortés-Hernández, new species (Guatemala: Totonicapán, Jalapa, San Marcos); and Isodacrys okuiltontli Cortés Hernández, new species (Mexico: Oaxaca). Insights into the monophyly of Isodacrys and its phylogenetic relationships with other Tanymecini based on adult morphology are given by implementing a phylogenetic analysis of 43 terminals (21 ingroup, 22 outgroup) coded for 72 adult morphological characters. Characters were discussed and highlighted for the inclusion in the phylogenetic analysis. Final analysis yielded two most-parsimonious cladograms of 242 steps, which support the monophyly of Isodacrys. Isodillex Cortés-Hernández, new genus is here described to accommodate Isodillex minutum (Sharp, 1911), new combination and Isodillex plumosum Cortés-Hernández, new species (Mexico: Zacatecas). Isodillex was recovered as sister group of Isodacrys. Key to separate Isodacrys species, occurrence map and habitus photographs are also provided.
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The world species of Apenesia are revised. Twenty-seven previously described species of Pristocerinae are addressed to Apenesia: A. amoena Evans, A. bicolor Vargas Terayama, A. chontalica Westwood, A. conradti Kieffer, A. delicata Evans, A. dominica Evans, A. flavipes Cameron, A. formosa Vargas Terayama, A. laevigata (Evans), A. levis Kieffer, A. leytensis (Terayama), A. makiharai (Sawada, Terayama Mita), A. malaitensis Brues, A. miki (Terayama), A. modesta (Smith), A. nigra Kieffer, A. parasitica (Smith), A. perlonga Corrêa Azevedo, A. proxima Kieffer, A. punctata Kieffer, A. sahyadrica Azevedo Waichert, A. singularis Lanes Azevedo, A. sjostedti (Tullgren), A. substriata Kieffer, A. unicolor Kieffer, and A. vaurieorum Evans. Additionally, 21 new species are described and illustrated: Apenesia amenula sp. nov.; A. aniela sp. nov.; A. azeda sp. nov.; A. beliella sp. nov.; A. berela sp. nov.; A. bifiela sp. nov.; A. celiela sp. nov.; A. chandela sp. nov.; A. cila sp. nov.; A. colombela sp. nov.; A. elela sp. nov.; A. esila sp. nov.; A. eura sp. nov.; A. farela sp. nov.; A. gabela sp. nov.; A. girena sp. nov.; A. goela sp. nov.; A. itoiela sp. nov.; A. joela sp. nov.; A. juliela sp. nov. and A. kelsiela sp. nov. The sexual association of A. celiela and A. azeda was possible due to biological data information. A key to species based on males is presented. The genus Apenesia is a parasitiod of beetles that live in galleries in dead wood or seeds.
Asunto(s)
Himenópteros , Distribución Animal , Animales , MasculinoRESUMEN
RESUMEN Dyophthorinae es una subfamilia con varias especies asociadas principalmente al consumo de monocotiledóneas, siendo consideradas en Colombia plaga en cultivos de palmas, musáceas y granos como maíz, trigo, sorgo y arroz. En este documento se presenta un listado de las especies de Dryophthorinae para los departamentos de la costa Caribe colombiana, construido a partir de las visitas a colecciones entomológicas y de la revisión de literatura. Para la región se registraron 11 especies: Cosmopolites sordidus, Dynamis borassi, Mesocordylus striatus, Metamasius hemipterus, M. hebetatus, Polytus mellerborgii, Rhynchophorus palmarum, Rhodobaenus sp., Rhinostomus barbirostris, Sitophilus zeamais y S. oryzae, algunas de las cuales se documentan por primera vez para esta zona. Se discute la importancia de realizar muestreos sistemáticos de este grupo y estudios tendientes a mejorar el conocimiento sobre su distribución y biología, así como su impacto en producciones agrícolas y su potencial como plagas en el país.
ABSTRACT Dryophthorinae is a relatively small weevil subfamily associated mainly with monocots. There are species in Colombia considered pests in the palm and Musaceae crops. In this document, a list of the species of Dryophthoridae for the departments of the Colombian Caribbean coast is presented, based on data from entomological collections and literature review. For the region, 11 species were recorded: Cosmopolites sordidus, Dynamis borassi, Mesocordylus striatus, Metamasius hemipterus, M. hebetatus, Polytus mellerborgii, Rhynchophorus palmarum, Rhodobaenus sp., Rhinostomus barbirostris, Sitophilus zeamais and S. oryzae, some of which are registered for the first time for the area. The importance of systematically sampling this group, and studies leading to improve knowledge about their distribution and biology, as well as its impact on agricultural production and their potential as pests in the country, are discussed.
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We report the first record of occurrence of Loncophorus longinasus in fruits of munguba, Pseudobombax munguba, in the state of Amazonas, Brazil. Some morphological and biological aspects of L. longinasus are presented. Adults were obtained through natural emergence from munguba fruits that opened for seed dispersal. The fruits had perforations leading to galleries through the exocarp. Inside the fruit, larvae were found at the seed insertion points on the central seed attachment structure. The pupae developed in a cocoon at the same structure and turned mature simultaneously with the capsule opening. Together with the larvae, the presence of ants (Pseudomyrmex sp.) was observed, that apparently maintained the galleries open for access and feeding on larval exudates.(AU)
Este é o primeiro registro de ocorrência de Loncophorus longinasus em frutos da árvore munguba, Pseudobombax munguba, no Estado do Amazonas, Brasil. Alguns aspectos morfológicos e biológicos de L. longinasus são apresentados. Adultos foram obtidos quando emergiam naturalmente durante a abertura do fruto da munguba para a dispersão das sementes. Os frutos apresentaram perfurações que formavam galerias através do exocarpo. Dentro do fruto, foram encontradas larvas em pontos de inserção de sementes na estrutura central. Pupas foram encontradas em casulos na mesma estrutura central, e se transformaram em adultos simultaneamente com a abertura da cápsula. Junto às larvas, detectamos a presença de formigas (Pseudomyrmex sp.), que possivelmente mantêm abertas as galerias no exocarpo para acesso e consumo dos exsudatos das larvas.(AU)
Asunto(s)
Animales , Gorgojos/anatomía & histología , Gorgojos/clasificación , Malvaceae/parasitologíaRESUMEN
The mature larva and pupa of Conotrachelus dimidiatus Champion, 1904 (Curculionidae: Molytinae) are morphologically re-described, keyed and, for the first time, compared with known larvae and pupae of other Conotrachelus species. The chaetotaxy of the larval and pupal body in the genus Conotrachelus is probably strictly uniform. The immature stages of described species are also compared with available data on the immature stages of genera from several tribes in the subfamily Molytinae. All larvae of Conotrachelus have a distinct endocranial line of a different size and a frons with only three setae. The states of these two distinct characteristics in larvae of the eight known Conotrachelus species are constant and unique compared to other tribes in the subfamily Molytinae. In Central Mexico, overwintering Conotrachelus beetles emerge in July and then feed and mate on host plants. Larvae are endophagous within the fruits. In September and October, the larvae pupate in the soil. This new information will be very useful in the application of pesticides to the fight against this well-known pest in Mexico.
Asunto(s)
Escarabajos , Gorgojos , Animales , Larva , México , PupaRESUMEN
Coptoborus silviasalasi Atkinson, new species is described from Oaxaca, Mexico. New synonyms include: Dryocoetoides capucinus Eichhoff, 1869 (=monachus Blandford, 1898) and Taurodemus sharpi Blandford, 1898 (= sharpi lenis Wood, 1974). Significant new distribution records are given for Xyleborini from Mexico and Central America.
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Gorgojos , Animales , América Central , México , Estados UnidosRESUMEN
The grape weevil, Naupactus xanthographus Germar (Coleoptera: Curculionidae), is a polyphagous insect native to southern South America that causes considerable damage in grape and other fruit species. In this study, the morphology and ultrastructure of the antennae and the antennal sensilla of N. xanthographus were investigated using scanning electron microscopy and transmission electron microscopy. The antennae consist of a scape, a pedicel, a funicle, and a zone called the "club," which are all formed by a total of 12 antennomers. Different types of sensilla were observed: sensilla trichoidea, sensilla chaetica type 1 and 2, sensilla basiconica, and sensilla rod-like. No sexual dimorphism was observed. The possible functions of the sensilla are discussed in relation to their morphology and ultrastructure.
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Sensilos/ultraestructura , Gorgojos/anatomía & histología , Animales , Femenino , Frutas/parasitología , Resistencia a los Insecticidas , Insecticidas/farmacología , Masculino , Microscopía Electrónica de Rastreo , Microscopía Electrónica de Transmisión , Vitis/parasitologíaRESUMEN
The South American rice water weevil Oryzophagus oryzae (Costa Lima) (Coleoptera: Curculionidae) is a key pest of irrigated rice in Brazil. Light traps could be used as an integrated pest management (IPM) strategy since these weevils have strong phototropism. Thus, the aim of this study was to search the attractiveness of LEDs of different wavelengths to O. oryzae to define the best light-emitting diodes (LED) arrangement to build the lamp of photovoltaic light traps. LEDs of different wavelengths were tested in a dark room with a hexagonal arena with exits to light sources. Groups of 200 insects were released in the center of the arena and captured at the end of exposure time in plastic bags placed in the exits. The LEDs in the short-wave band of the light spectrum (365 and 460 nm) and white LEDs, as well as the light mix of 365 with 460 nm or white LEDs, were attractive to O. oryzae. Beyond the LEDs with ultraviolet (UV) spectrum, the LEDs above 380 nm were the most attractive and, this way, might be used to build LED lamps of photovoltaic light traps.(AU)
Uma das pragas-chave do arroz irrigado é a bicheira-da-raiz, denominação comum atribuída às larvas do gorgulho aquático Oryzophagus oryzae (Costa Lima) (Coleoptera: Curculionidae). A utilização de armadilhas luminosas poderia ser uma alternativa viável no manejo integrado, pois esse gorgulho apresenta elevado fototropismo positivo. Assim, objetivou-se determinar a atratividade de diodos emissores de luz (LEDs) de diferentes comprimentos de onda ao O. oryzae e definir o seu melhor arranjo para compor a lâmpada de armadilhas luminosas fotovoltaicas. LEDs de diferentes comprimentos de onda foram testados em sala escura, em uma arena hexagonal com saídas para as fontes de luz. Grupos de 200 indivíduos foram liberados no centro da arena e capturados em sacos plásticos nas saídas ao fim do tempo de exposição. Os LEDs da faixa do espectro luminoso de ondas curtas (365 e 460 nm) e LEDs brancos, bem como as misturas de luzes de LEDs 365 com 460 nm ou branco, foram atrativos ao O. oryzae. Entre os LEDs com espectro ultravioleta, os mais atrativos foram aqueles acima de 380 nm, devendo estes compor, prioritariamente, lâmpadas de LED para uso nas armadilhas luminosas fotovoltaicas.(AU)
Asunto(s)
Oryza , Escarabajos/patogenicidad , Fototropismo , Plagas Agrícolas , LuzRESUMEN
The South American rice water weevil Oryzophagus oryzae (Costa Lima) (Coleoptera: Curculionidae) is a key pest of irrigated rice in Brazil. Light traps could be used as an integrated pest management (IPM) strategy since these weevils have strong phototropism. Thus, the aim of this study was to search the attractiveness of LEDs of different wavelengths to O. oryzae to define the best light-emitting diodes (LED) arrangement to build the lamp of photovoltaic light traps. LEDs of different wavelengths were tested in a dark room with a hexagonal arena with exits to light sources. Groups of 200 insects were released in the center of the arena and captured at the end of exposure time in plastic bags placed in the exits. The LEDs in the short-wave band of the light spectrum (365 and 460 nm) and white LEDs, as well as the light mix of 365 with 460 nm or white LEDs, were attractive to O. oryzae. Beyond the LEDs with ultraviolet (UV) spectrum, the LEDs above 380 nm were the most attractive and, this way, might be used to build LED lamps of photovoltaic light traps.(AU)
Uma das pragas-chave do arroz irrigado é a bicheira-da-raiz, denominação comum atribuída às larvas do gorgulho aquático Oryzophagus oryzae (Costa Lima) (Coleoptera: Curculionidae). A utilização de armadilhas luminosas poderia ser uma alternativa viável no manejo integrado, pois esse gorgulho apresenta elevado fototropismo positivo. Assim, objetivou-se determinar a atratividade de diodos emissores de luz (LEDs) de diferentes comprimentos de onda ao O. oryzae e definir o seu melhor arranjo para compor a lâmpada de armadilhas luminosas fotovoltaicas. LEDs de diferentes comprimentos de onda foram testados em sala escura, em uma arena hexagonal com saídas para as fontes de luz. Grupos de 200 indivíduos foram liberados no centro da arena e capturados em sacos plásticos nas saídas ao fim do tempo de exposição. Os LEDs da faixa do espectro luminoso de ondas curtas (365 e 460 nm) e LEDs brancos, bem como as misturas de luzes de LEDs 365 com 460 nm ou branco, foram atrativos ao O. oryzae. Entre os LEDs com espectro ultravioleta, os mais atrativos foram aqueles acima de 380 nm, devendo estes compor, prioritariamente, lâmpadas de LED para uso nas armadilhas luminosas fotovoltaicas.(AU)
Asunto(s)
Oryza , Escarabajos/patogenicidad , Fototropismo , Plagas Agrícolas , LuzRESUMEN
BACKGROUND: Using syntactic and semantic conventions of the taxonomic concept approach (Franz et al. 2015), we describe three newly recognized fossil broad-nosed weevils (Coleoptera: Curculionidae: Entiminae) preserved in Early Miocene amber (ca. 20.4-16.0 mya) from the Dominican Republic: Scelianoma compactasp. n. sec. Franz & Zhang (2017) (henceforth abbreviated as [FZ2017]), Tropirhinus palpebratussp. n. [FZ2017], and Diaprepes anticussp. n. [FZ2017]. The taxonomic assignment of the amber inclusions is grounded in a preceding phylogenetic analysis by Franz (2012). As many as 88 of the 143 therein identified characters were coded for the fossils, whose traits are largely congruent with those present in extant congeners while also differing in ways that justify their new nomenclatural and taxonomic status. NEW INFORMATION: We present detailed images, descriptions, and phylogenetically informed diagnoses for the three new species-level entities, along with logically consistent Region Connection Calculus (RCC-5) alignments of the amended genus-level classifications for Scelianoma Franz and Girón 2009 [FZ2017], Tropirhinus Schoenherr 1823 [FZ2017], and Diaprepes Schoenherr 1823 [FZ2017] - in relation to 2-4 preceding classifications published in 1982-2012. The description of Scelianoma compacta [FZ2017] from Hispaniola is indicative of a more widespread historical range of Scelianoma [FZ2017] than reflected in the extant, southwestern Puerto Rican Scelianoma elydimorpha Franz and Girón 2009 sec. Franz and Girón (2009). The presence of Diaprepes anticus [FZ2017] in Hispaniola during the Early Miocene suggests an eastward directed process of island colonization and likely speciation of members of Diaprepes [FZ2017], given that most extant relatives occur throughout the Lesser Antilles. The herein presented data will facilitate more reliable reconstructions of historical biographic processes thought to have played a prominent role in the diversification of the West Indian and Neotropical mainland broad-nosed weevil lineages.
RESUMEN
Previous studies have shown that the boll weevil, Anthonomus grandis, is attracted to constitutive and conspecific herbivore-induced cotton volatiles, preferring the blend emitted by cotton at the reproductive over the vegetative stage. Moreover, this preference was paralleled by the release of the acyclic homoterpenes (tetranorterpenes) (E)-4,8-dimethyl-1,3,7-nonatriene (DMNT) and (E,E)-4,8,12-trimethyltrideca-1,3,7,11-tetraene (TMTT) in Delta Opal cotton being higher at the vegetative than at the reproductive stage. Here, we evaluated whether this difference in release of acyclic homoterpenes also occurred in other cotton varieties, and if boll weevils could recognize these compounds as indicators of a specific cotton phenological stage. Results showed that cotton genotypes CNPA TB-90, BRS-293 and Delta Opal all produced higher levels of DMNT and TMTT at the vegetative stage than at the reproductive stage and that these homoterpenes allowed for principal component analysis separation of volatiles produced by the two phenological stages. Electroantennograms confirmed boll weevil antennal responses to DMNT and TMTT. Behavioral assays, using Y-tube olfactometers, showed that adding synthetic homoterpenes to reproductive cotton volatiles (mimicking cotton at the vegetative stage in terms of homoterpene levels) resulted in reduced attraction to boll weevils compared to that to unmodified reproductive cotton. Weevils showed no preference when given a choice between plants at the vegetative stage and the vegetative stage-mimicked plant. Altogether, the results show that DMNT and TMTT are used by boll weevils to distinguish between cotton phenological stages.
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Conducta Animal/efectos de los fármacos , Terpenos/química , Terpenos/farmacología , Gorgojos/efectos de los fármacos , Animales , Bioensayo , Femenino , Genotipo , Gossypium/genética , Gossypium/metabolismo , Masculino , Terpenos/metabolismoRESUMEN
The sugarcane stem weevil, Acrotomopus atropunctellus (Boheman) (Curculionidae: Molytinae: Cholini) is an important economic pest from the Northwestern region of Argentina. Analyses of the headspace volatiles produced by separated males and females revealed one male-specific compound. Its structural identification is reported here in using gas chromatography coupled with mass spectroscopy analysis and chemical micro-reactions. Besides, two laboratory olfactometry assays allowed us to propose 6-methyl-5-hepten-2-one (sulcatone) as an aggregation pheromone for this insect, being attractive to both conspecific males and females. This compound is reported for the first time as involved in the Curculionidae family communication.
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Feromonas/metabolismo , Gorgojos/metabolismo , Animales , Conducta Animal , Femenino , Cromatografía de Gases y Espectrometría de Masas , Masculino , Feromonas/química , Feromonas/aislamiento & purificación , Gorgojos/químicaRESUMEN
Where their geographic and host ranges overlap, sibling species of tree-killing bark beetles may simultaneously attack and reproduce on the same hosts. However, sustainability of these potentially mutually beneficial associations demands effective prezygotic reproductive isolation mechanisms between the interacting species. The pine bark beetle, Dendroctonus frontalis Zimmermann, is syntopic in the Central American region with a recently described sibling species, Dendroctonus mesoamericanus Armendáriz-Toledano and Sullivan, but mechanisms for their reproductive isolation are uncertain. We investigated whether semiochemicals mediate species discrimination by mate-seeking males of both species. In olfactometer bioassays, walking males of both species strongly preferred odors from gallery entrances of conspecific females. Coupled gas chromatography-electroantennographic detection and gas chromatography-mass spectrometry isolated 16 olfactory stimulants for males in these odors, but only two, ipsdienol and endo-brevicomin (both from D. mesoamericanus females), differed in quantity in female-associated odors between the species. In olfactometer bioassays, with 10, 1, or 0.1 female entrance equivalents of synthetic semiochemicals, the combination of ipsdienol and endo-brevicomin inhibited responses of male D. frontalis and enhanced responses of male D. mesoamericanus to two compounds associated with female entrances of both species (the pheromone component frontalin and host odor α-pinene). We conclude that ipsdienol and endo-brevicomin, pheromone components produced by females of just one of the two species (D. mesoamericanus), mediate interspecific mate discrimination by males of both species and provide an apparently symmetrical reproductive isolation mechanism.
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Atractivos Sexuales/metabolismo , Conducta Sexual Animal , Gorgojos/fisiología , Animales , Femenino , Masculino , México , Especificidad de la EspecieRESUMEN
α-Amylases are common enzymes responsible for hydrolyzing starch. Insect-pests, whose larvae develop in seeds, rely obligatorily on α-amylase activity to digest starch, as their major food source. Considering the relevance of insect α-amylases and the natural α-amylase inhibitors present in seeds to protect from insect damage, we report here the molecular cloning and nucleotide sequence of the full-length AmyHha cDNA of the coffee berry borer, Hypothenemus hampei, a major insect-pest of coffee crops. The AmyHha sequence has 1879 bp, containing a 1458 bp open reading frame, which encodes a predicted protein with 485 amino acid residues, with a predicted molecular mass of 51.2 kDa. The deduced protein showed 55-79% identity to other insect α-amylases, including Anthonomus grandis, Ips typographus and Sitophilus oryzae α-amylases. In depth analysis revealed that the highly conserved three amino acid residues (Asp184, Glu220, and Asp285), which compose the catalytic site are also presented in AmyHha amylase. The AmyHha gene seems to be a single copy in the haploid genome and AmyHha transcription levels were found higher in L2 larvae and adult insects, both corresponding to major feeding phases. Modeling of the AmyHha predicted protein uncovered striking structural similarities to the Tenebrio molitor α-amylase also displaying the same amino acid residues involved in enzyme catalysis (Asp184, Glu220 and Asp285). Since AmyHha gene was mostly transcribed in the intestinal tract of H. hampei larvae, the cognate α-amylase could be considered a high valuable target to coffee bean insect control by biotechnological strategies.
Asunto(s)
Escarabajos/fisiología , ADN Complementario/genética , Conducta Alimentaria , alfa-Amilasas/genética , Secuencia de Aminoácidos , Animales , Secuencia de Bases , Clonación Molecular , Escarabajos/clasificación , Escarabajos/enzimología , Modelos Moleculares , Datos de Secuencia Molecular , Sistemas de Lectura Abierta , Filogenia , Reacción en Cadena en Tiempo Real de la Polimerasa , Homología de Secuencia de Aminoácido , alfa-Amilasas/químicaRESUMEN
Presently the only keys available for identification of genera of Anthonomini are limited to those of the United States of America and Canada. A dichotomous key is presented to identify all genera of Mexican and Central American Anthonomini. Previous keys do not include the genera Achia, Botanebius, Loncophorus, Loncophorellus and Melexerus. A brief synopsis is given for each genus and photographs of representative species are included.