One maternal lineage leads the expansion of Thaumastocoris peregrinus (Hemiptera: Thaumastocoridae) in the New and Old Worlds.

The bronze bug, Thaumastocoris peregrinus, an Australian native insect, has become a nearly worldwide invasive pest in the last 16 years and has been causing significant damage to eucalypts (Myrtaceae), including Eucalyptus spp. and Corymbia spp. Its rapid expansion leads to new questions about pathways and routes that T. peregrinus used to invade other continents and countries. We used mtDNA to characterize specimens of T. peregrinus collected from 10 countries where this species has become established, including six recently invaded countries: Chile, Israel, Mexico, Paraguay, Portugal, and the United States of America. We then combined our mtDNA data with previous data available from South Africa, Australia, and Europe to construct a world mtDNA network of haplotypes. Haplotype A was the most common present in all specimens of sites sampled in the New World, Europe, and Israel, however from Australia second more frequently. Haplotype D was the most common one from native populations in Australia. Haplotype A differs from the two major haplotypes found in South Africa (D and G), confirming that at least two independent invasions occurred, one from Australia to South Africa, and the other one from Australia to South America (A). In conclusion, Haplotype A has an invasion success over many countries in the World. Additionally, analyzing data from our work and previous reports, it is possible to suggest some invasive routes of T. peregrinus to predict such events and support preventive control measures.

Susceptibility of Brazilian Populations of Chrysodeixis includens (Lepidoptera: Noctuidae) to Selected Insecticides.

Soybean looper (SBL), Chrysodeixis includens (Walker) (Lepidoptera: Noctuidae), is an important pest of soybean and cotton in Brazil. The use of insecticides is one of the main control tactics against this pest. To support Integrated Pest Management (IPM) and Insect Resistance Management (IRM) programs, we characterized the susceptibility of Brazilian populations of SBL to insecticides. Field populations were collected from soybean fields during the 2016-2017 and 2017-2018 crop seasons. In the laboratory, late L2/early L3 larvae were exposed to insecticides in diet-overlay or topical bioassays. Field populations of SBL showed high susceptibility to spinetoram (LC50 = 0.074-0.25 µg a.i. per cm2), indoxacarb (LC50 = 0.46-0.94 µg a.i. per cm2), thiodicarb (LC50 = 9.14-36.61 µg a.i. per cm2), chlorantraniliprole (LC50 = 0.15-0.57 µg a.i. per cm2), flubendiamide (LC50 = 0.45-2.01 µg a.i. per cm2), and chlorfenapyr (LC50 = 0.15-0.25 µg a.i. per cm2); the resistance ratios were less than 16-fold. In contrast, SBL populations have reduced susceptibility to lambda-cyhalothrin (LC50 = 3.71-9.54 µg a.i./cm2), methoxyfenozide (LC50 = 0.67-4.23 µg a.i. per cm2), novaluron (LC50 = 27.52-77.63 µg a.i. per cm2), and teflubenzuron (LC50 = 13.41-73.02 µg a.i. per cm2). The resistance ratios relative to a Lab population (susceptible of reference) was up to 38-, 63-, 1,553-, and 5,215-fold, respectively. These high resistance ratios can be associated with resistance evolution. Implications of these findings to IPM and IRM programs are discussed.

Abundance and Diversity in the Melolonthidae Community in Cultivated and Natural Grassland Areas of the Brazilian Pampa.

Annual crops or exotic trees for cellulose extraction have replaced natural grassland areas of the Brazilian Pampa biome. These activities have been intensified in recent years and may lead to changes in the white grub complex. The objective of this study was to characterize the diversity and abundance of white grubs in cultivated and natural grassland areas of the Brazilian Pampa biome. We conducted samplings in natural grassland and cultivated areas throughout 18 locations in the Brazilian Pampa. Diversity index and nonmetric multidimensional scaling (NMDS) were used to compare the Melolonthidae community within and between cultivated and natural grassland areas. Diloboderus abderus Sturm, Cyclocephala modesta Burmeister, and Plectris sp.5 (Coleoptera: Melolonthidae) were the most abundant taxa, accounting for 49.08% of all white grubs collected from both land use types. Abundance, diversity, and evenness indices were greater in natural grassland than in cultivated areas. The NMDS demonstrated that natural grassland and cultivated areas share similar white grub species assemblages, with 22 species collected in both land use types. Our data suggest that most of the Melolonthidae species collected in the Brazilian Pampa are capable of persisting in cultivated areas. This is the first work characterizing the Melolonthidae community throughout the Brazilian Pampa, which is vital for implementing pest management tactics and conservation of beneficial species.

Susceptibility of the Lesser Mealworm, Alphitobius diaperinus (Coleoptera: Tenebrionidae), From Broiler Farms of Southern Brazil to Insecticides.

The lesser mealworm, Alphitobius diaperinus (Panzer, 1797) (Coleoptera: Tenebrionidae), is considered the primary insect pest in broiler farms in Brazil. In this study, we characterized the susceptibility of A. diaperinus populations from broiler farms of southern Brazil to cypermethrin and chlorpyrifos. Larvae and adults of A. diaperinus were exposed to these technical insecticides diluted in acetone in residual bioassays. A geographic variation in the susceptibility of larvae and adults of A. diaperinus to both insecticides was detected. The larval LC50 for cypermethrin ranged from 0.43 to 7.33 µg a.i./cm2. Two populations from Santa Catarina state presented higher resistance ratios of 13.6- and 17-fold. When adults were exposed to cypermethrin, the LC50 ranged from 0.46 to 4.93 µg a.i./cm2, with population SC-3 from Santa Catarina having lower susceptibility (resistance ratio of 10.7-fold). When exposed to chlorpyrifos, A. diaperinus larvae present LC50 values ranging from 0.21 to 4.30 µg a.i./cm2. Larvae from Paraná and Santa Catarina (SC-1 population) presented the highest resistance ratios, ranging from 10- to 20-fold. In adults, the LC50 of chlorpyrifos ranged from 0.17 to 5.30 µg a.i./cm2, showing a maximum resistance ratio of 31-fold in a population from Paraná state. Based on LC99 values, candidate diagnostic concentrations of 15 and 12 µg a.i./cm2 of cypermethrin and chlorpyrifos, respectively, were also estimated for the resistance monitoring of A. diaperinus in Brazil. The implications of these results in Insect Resistance Management are discussed.

Selection, isolation, and identification of fungi for bioherbicide production

Abstract Production of a bioherbicide for biological control of weeds requires a series of steps, from selection of a suitable microbial strain to final formulation. Thus, this study aimed to select fungi for production of secondary metabolites with herbicidal activity using biological resources of the Brazilian Pampa biome. Phytopathogenic fungi were isolated from infected tissues of weeds in the Pampa biome. A liquid synthetic culture medium was used for production of metabolites. The phytotoxicity of fungal metabolites was assessed via biological tests using the plant Cucumis sativus L., and the most promising strain was identified by molecular analysis. Thirty-nine fungi were isolated, and 28 presented some phytotoxic symptoms against the target plant. Fungus VP51 belonging to the genus Diaporthe showed the most pronounced herbicidal activity. The Brazilian Pampa biome is a potential resource for the development of new and sustainable chemical compounds for modern agriculture.

Selection, isolation, and identification of fungi for bioherbicide production.

Production of a bioherbicide for biological control of weeds requires a series of steps, from selection of a suitable microbial strain to final formulation. Thus, this study aimed to select fungi for production of secondary metabolites with herbicidal activity using biological resources of the Brazilian Pampa biome. Phytopathogenic fungi were isolated from infected tissues of weeds in the Pampa biome. A liquid synthetic culture medium was used for production of metabolites. The phytotoxicity of fungal metabolites was assessed via biological tests using the plant Cucumis sativus L., and the most promising strain was identified by molecular analysis. Thirty-nine fungi were isolated, and 28 presented some phytotoxic symptoms against the target plant. Fungus VP51 belonging to the genus Diaporthe showed the most pronounced herbicidal activity. The Brazilian Pampa biome is a potential resource for the development of new and sustainable chemical compounds for modern agriculture.

Production of bioherbicide by Phoma sp. in a stirred-tank bioreactor.

The objective of this work was to produce an herbicide by submerged fermentation in a stirred-tank bioreactor and to assess the potential herbicidal in pre-emergence, post-emergence, and in a detached leaves of Cucumis sativus var species. wisconsin (cucumber) and Sorghum bicolor (sorghum) species. Fermentations were carried out in a stirred-tank bioreactor with useful volume of 3L. Stirring rate (40, 50, and 60 rpm) and aeration (1, 2 and 3 vvm) were the variables studied for bioherbicide production. Fermented broth was fractioned with different solvents to identify the molecules produced by the fungus in a multi-dimensional gas chromatograph system. Bioherbicide showed 100% inhibition of germination of both species in the pre-emergence tests. From detached leaves tests were verified yellowish lesions in Cucumis sativus and necrotic lesions on leaves of Sorghum bicolor. Post-emergence test presented variation of the phytotoxicity from 25 to 66% for the species C. sativus and from 32 to 58% by S. bicolor. The metabolites produced by submerged fermentation of Phoma sp. presented activity in pre-emergence, post-emergence, and detached leaves of C. sativus and S. bicolor and it could be an alternative in the future for weed control.

White grubs (Coleoptera, Melolonthidae) in the "Planalto Region", Rio Grande do Sul state, Brazil: Key for identification, species richness and distribution

White grubs (Coleoptera, Melolonthidae) in the "Planalto Region", Rio Grande do Sul state, Brazil: Key for identification, species richness and distribution. The objective of this study was to survey the occurrence and geographic distribution of white grub species (Coleoptera, Melolonthidae) in cultivated and non-cultivated fields of the "Planalto Region", Rio Grande do Sul state, Brazil and develop a key at genus-level. Twenty-eight species from 15 genera and three subfamilies were recorded: Dynastinae, Melolonthinae and Rutelinae. The species or genera recorded for the first time in the state are: Cyclocephala metrica, C. tucumana, Isonychus albicinctus, Liogenys bidenticeps, L. fusca, L. obesa and L. sinuaticeps, Paranomala violacea, as well as unidentified species of Amononyx, Dicrania, Leucothyreus, Macrodactylus, Plectris and Rhizogeniates. Among the species recorded, 23 were associated with winter crops. Only Cyclocephala metrica, Dyscinetus rugifrons, two species of Leucothyreus and one species of the tribe Sericini were not present in cultivated crop fields. Cyclocephala flavipennis and Diloboderus abderus occurred in most of the municipalities sampled, often associated with Plectris sp., C. modesta and C. putrida. The highest richness of melolonthids was concentrated in the northeast of the Planalto region.

Managing the sugarcane borer, Diatraea saccharalis, and corn earworm, Helicoverpa zea, using Bt corn and insecticide treatments.

The sugarcane borer, Diatraea saccharalis (Fabricius) (Lepidoptera: Crambidae) and the corn earworm, Helicoverpa zea (Boddie) (Lepidoptera: Noctuidae), are important pests of corn in Brazil and have not been successfully managed, because of the difficulty of managing them with pesticides. The objective of this study was to evaluate the effect of Bt corn MON810, transformed with a gene from Bacillus thuringiensis Berliner (Bacillales: Bacillaceae) insecticide seed treatment, and foliar insecticide spray using treatments developed for control of the fall armyworm, Spodoptera frugiperda (J. E. Smith) (Lepidoptera: Noctuidae), which is the major pest of corn. The experiments were done under field conditions in early- and late-planted corn in the state of Rio Grande do Sul, Brazil, and in the laboratory. The MON810 corn reduced infestations and damage by D. saccharalis and H. zea. The insecticides used in seed treatments or foliar sprays did not affect D. saccharalis and H. zea infestations or damage levels. The exception was the insecticide seed treatment in non-transformed corn, which reduced early infestations of D. saccharalis. The MON810 corn, therefore, can be used for managing these two pest species, especially D. saccharalis.

First record of species of Liogenys (Coleoptera, Melolonthidae) associated with winter grain crops in Rio Grande do Sul (Brazil)

First record of species of Liogenys (Coleoptera, Melolonthidae) associated with winter crops in Rio Grande do Sul (Brazil). Some species of Liogenys Guerín-Meneville, 1831 are known to cause damage to soybean, corn and other summer crops in the Brazilian "Cerrado" region. This work aimed to identify melolontid larvae associated with winter crops in Rio Grande do Sul state. Larvae and adults of Liogenys species were collected from the municipalities of Ijuí, Cruz Alta, Manoel Viana, São Luiz Gonzaga and São Francisco de Assis. The specimens were identified as L. bidenticeps Moser, 1919; L. fusca Blanchard, 1851, L. obesa Burmeister, 1855, and L. sinuaticeps Moser, 1918. This is the first record of these species associated with winter grain crops, for Rio Grande do Sul State. Biological and behavioral studies are necessary to confirm their association with host plants.

Primeiro registro de ocorrência de espécies de Liogenys (Coleoptera, Melolonthidae) associadas a culturas de inverno no Rio Grande do Sul (Brasil). As espécies de Liogenys Guerín-Meneville, 1831 são conhecidas no "Cerrado" brasileiro por causar danos em culturas de verão como soja e milho. O trabalho teve por objetivo identificar as larvas de melolontídeos que ocorrem nas culturas de grãos de inverno no Rio Grande do Sul. Larvas e adultos de Liogenys foram coletados nos municípios de Ijuí, Cruz Alta, Manoel Viana, São Luiz Gonzaga e São Francisco de Assis. As espécies foram identificadas como Liogenys bidenticeps Moser, 1919, L. fusca Blanchard, 1851, L. obesa Burmeister, 1855 and L. sinuaticeps Moser, 1918. Trata-se do primeiro registro de ocorrência destas espécies associadas a culturas de grãos de inverno, no Estado de Rio Grande do Sul. São necessários estudos de biologia e comportamento para confirmar sua associação com plantas hospedeiras.

[Host weeds of Rhopalosiphum rufiabdominalis (Sasaki) (Hemiptera: Aphididae) in areas of irrigated rice]. / Plantas infestantes hospedeiras de Rhopalosiphum rufiabdominalis (Sasaki) (Hemiptera: Aphididae) em áreas de cultivo de arroz irrigado.

Rhopalosiphum rufiabdominalis (Sasaki) is an insect of world-wide distribution that damages irrigated rice. From September, 2004 to February, 2005, nymphs and adults of this aphid were collected in several host weeds of rice farms in Alegrete, Quaraí and Uruguaiana, located in Western of State of Rio Grande do Sul, and Restinga Seca, in Central region of this State, Brazil. The insect was found in the root of Andropogon bicornis (West Indian foxtail), Echinochloa colona (jungle rice), Oryza sativa (volunteer rice and red-rice), Paspalum sp. (paspalum) and Soliva pterosperma (lawn burweed).

[Biological characteristics of the egg phase of citrus root weevils]. / Aspectos biológicos do período embrionário dos curculionídeos-das-raízes dos citros.

The goal of this work was to study some characteristics of the egg phase of three species of citrus root weevils. The insects were collected from citrus plants in Itapetininga, SP, and brought to the Laboratório de Biologia de Insetos of ESALQ/USP, in Piracicaba, SP, where the species Naupactus cervinus (Boheman), Naupactus versatilis (Hustache) and Parapantomorus fluctuosus (Boheman) were kept. Duration and viability of the egg phase were evaluated, and the lower temperature threshold and thermal constant (K) were calculated for these species. The species of citrus root weevils showed different duration of egg phases. The egg phase ranged from 40.4 to 13.8 N. cervinus, from 38.7 to 20.0 days for N. versatilis, and from 35.0 to 13.8 days for P. fluctuosus, depending upon temperature. The temperature thresholds of this stage were 8.1, 8.3, and 9.9 masculineC at thermal constant was 385.7, 397.7 and 294.1 degree-days, for N. cervinus, N. versatilis and P. fluctuosus respectively. The duration of the egg phases of N. cervinus and N. versatilis were similar at the same temperatures and P. fluctuosus had a faster development than Naupactus spp. in all temperatures tested.

[Mites associated with soybean crop in Rio Grande do Sul State, Brazil]. / Acaros associados à cultura da soja no Rio Grande do Sul.

During the last growing seasons, high infestations of phytophagous mites were observed in the State of Rio Grande do Sul, Brazil, becoming necessary to apply pesticides for their control. The objective of this study was to identify phytophagous and predatory mite species associated with soybean in ten counties of that state, during the 2002/03 and 2003/04 growing seasons, in five soybean cultivars (A 6001 RG, A 7001 RG, A 8000 RG, A 8100 RG, Anta 82), all genetically modified. In samples of soybean leaves four phytophagous mite species (Mononychellus planki (McGregor), Polyphagotarsonemus latus (Banks), Tetranychus desertorum Banks and Tetranychus gigas Pritchard & Baker) and two predatory mite species (Phytoseiulus fragariae Denmark & Schicha and Typhlodromalus aripo De Leon) were found. T. desertorum was found for the first time associated with soybean in the country. Phytoseiulus fragariae and T. aripo are reported for the first time on soybean. The potential of phytoseid mites as biological control agents in soybean crop was discussed. Among the hypotheses to explain the increasing infestation of soybean fields with phytophagous mites area are the progressively larger cultivated area, the dry spells observed in the last few years in the growing season, changes in soybean cropping system that led to increased use of pesticides and utilization of new soybean cultivars with morphological or biochemicals characteristics that favour the development of these mite populations.

Plantas infestantes hospedeiras de Rhopalosiphum rufiabdominalis (Sasaki) (Hemiptera: Aphididae) em áreas de cultivo de arroz irrigado / Host weeds of Rhopalosiphum rufiabdominalis (Sasaki) (Hemiptera: Aphididae) in areas of irrigated rice

Rhopalosiphum rufiabdominalis (Sasaki) é um inseto que causa dano à cultura do arroz-irrigado e tem ampla distribuição pelo mundo. Durante o período de setembro de 2004 a fevereiro de 2005, foram coletados ninfas e adultos desse afídeo em diversas plantas daninhas presentes em lavouras arrozeiras nos municípios de Alegrete, Quaraí e Uruguaiana, na região da fronteira oeste do Rio Grande do Sul, e Restinga Seca, na Região Central do Estado. O inseto foi encontrado nas raízes de Andropogon bicornis (capim-rabo-de-burro), Echinochloa colona (capim-arroz), arroz espontâneo e Oryza sativa (arroz-vermelho), Paspalum sp. (paspalum) e Soliva pterosperma (roseta).

Rhopalosiphum rufiabdominalis (Sasaki) is an insect of world-wide distribution that damages irrigated rice. From September, 2004 to February, 2005, nymphs and adults of this aphid were collected in several host weeds of rice farms in Alegrete, Quaraí and Uruguaiana, located in Western of State of Rio Grande do Sul, and Restinga Seca, in Central region of this State, Brazil. The insect was found in the root of Andropogon bicornis (West Indian foxtail), Echinochloa colona (jungle rice), Oryza sativa (volunteer rice and red-rice), Paspalum sp. (paspalum) and Soliva pterosperma (lawn burweed).

Aspectos biológicos do período embrionário dos curculionídeos-das-raízes dos citros / Biological characteristics of the egg phase of citrus root weevils

O objetivo deste trabalho foi estudar algumas características da fase de ovo de três espécies de curculionídeos-das-raízes dos citros. Os insetos foram coletados em citros em Itapetininga, SP, levados ao Laboratório de Biologia de Insetos da ESALQ/USP, em Piracicaba, SP, onde foram mantidas as espécies numericamente mais importantes: Naupactus cervinus (Boheman), Naupactus versatilis (Hustache) e Parapantomorus fluctuosus (Boheman). Dessas espécies foi avaliada duração e a viabilidade da fase de ovo e calculados o limite térmico inferior de desenvolvimento (Tb) e a constante térmica (K). As espécies de curculionídeos-das-raízes dos citros apresentaram diferenças quanto à fase de ovo. O período embrionário, variou de 40,4 a 18,6 dias para N. cervinus, 38,7 a 20,0 dias para N. versatilis e 35,0 a 13,8 dias P. fluctuosus, dependendo da temperatura. Os limiares térmicos inferiores de desenvolvimento foram de 8,1; 8,3 e 9,9°C com constante térmica 385,7; 397,7 e 294,1 graus dia (GD), respectivamente para N. cervinus, N. versatilis e P. fluctuosus. A duração da fase de ovo foi muito semelhante para N. cervinus e N. versatilis, nas mesmas temperaturas e P. fluctuosus, apresentou desenvolvimento mais rápido do que Naupactus spp., em todas as temperaturas testadas.

The goal of this work was to study some characteristics of the egg phase of three species of citrus root weevils. The insects were collected from citrus plants in Itapetininga, SP, and brought to the Laboratório de Biologia de Insetos of ESALQ/USP, in Piracicaba, SP, where the species Naupactus cervinus (Boheman), Naupactus versatilis (Hustache) and Parapantomorus fluctuosus (Boheman) were kept. Duration and viability of the egg phase were evaluated, and the lower temperature threshold and thermal constant (K) were calculated for these species. The species of citrus root weevils showed different duration of egg phases. The egg phase ranged from 40.4 to 13.8 N. cervinus, from 38.7 to 20.0 days for N. versatilis, and from 35.0 to 13.8 days for P. fluctuosus, depending upon temperature. The temperature thresholds of this stage were 8.1, 8.3, and 9.9°C at thermal constant was 385.7, 397.7 and 294.1 degree-days, for N. cervinus, N. versatilis and P. fluctuosus respectively. The duration of the egg phases of N. cervinus and N. versatilis were similar at the same temperatures and P. fluctuosus had a faster development than Naupactus spp. in all temperatures tested.

Ácaros associados à cultura da soja no Rio Grande do Sul / Mites associated with soybean crop in Rio Grande do Sul State, Brazil

Nas últimas safras agrícolas, foram observadas severas infestações de ácaros fitófagos em diversos municípios do Rio Grande do Sul, demandando a utilização de pesticidas para seu controle. Este trabalho teve como objetivo identificar as espécies de ácaros fitófagos e predadores associados à soja em dez municípios daquele estado, nas safras de 2002/03 e 2003/04, em cinco cultivares de soja (A 6001 RG, A 7001 RG, A 8000 RG, A 8100 RG, Anta 82), todas geneticamente modificadas. Em amostras de folhas foram encontradas quatro espécies de ácaros fitófagos (Mononychellus planki (McGregor), Polyphagotarsonemus latus (Banks), Tetranychus desertorum Banks e Tetranychus gigas Pritchard & Baker) e duas espécies de ácaros predadores (Phytoseiulus fragariae Denmark & Schicha e Typhlodromalus aripo De Leon). Tetranychus desertorum foi registrada pela primeira vez, associada à soja, no país. P. fragariae e T. aripo foram registradas pela primeira vez em soja. O potencial dos ácaros fitoseídeos como agentes de controle biológico na cultura da soja foi discutido. Dentre as hipóteses para o crescimento das infestações de culturas de soja com ácaros fitófagos estão a expansão progressiva da área cultivada, os veranicos observados nos últimos anos durante a estação de plantio, as modificações no sistema de cultivo da soja que levaram ao aumento no uso de pesticidas e a utilização de novas cultivares com características morfológicas ou bioquímicas que favorecem o desenvolvimento de populações desses ácaros.

During the last growing seasons, high infestations of phytophagous mites were observed in the State of Rio Grande do Sul, Brazil, becoming necessary to apply pesticides for their control. The objective of this study was to identify phytophagous and predatory mite species associated with soybean in ten counties of that state, during the 2002/03 and 2003/04 growing seasons, in five soybean cultivars (A 6001 RG, A 7001 RG, A 8000 RG, A 8100 RG, Anta 82), all genetically modified. In samples of soybean leaves four phytophagous mite species (Mononychellus planki (McGregor), Polyphagotarsonemus latus (Banks), Tetranychus desertorum Banks and Tetranychus gigas Pritchard & Baker) and two predatory mite species (Phytoseiulus fragariae Denmark & Schicha and Typhlodromalus aripo De Leon) were found. T. desertorum was found for the first time associated with soybean in the country. Phytoseiulus fragariae and T. aripo are reported for the first time on soybean. The potential of phytoseid mites as biological control agents in soybean crop was discussed. Among the hypotheses to explain the increasing infestation of soybean fields with phytophagous mites area are the progressively larger cultivated area, the dry spells observed in the last few years in the growing season, changes in soybean cropping system that led to increased use of pesticides and utilization of new soybean cultivars with morphological or biochemicals characteristics that favour the development of these mite populations.

[Occurrence of Rachiplusia nu (Guenée) (Lepidoptera: Noctuidae) on tobacco (Nicotiana tabacum L.) in Rio Grande do Sul, Brazil]. / Ocorrência de Rachiplusia nu (Guenée) (Lepidoptera: Noctuidae) em fumo (Nicotiana tabacum L.) no Rio Grande do Sul.

The occurrence of Rachiplusia nu (Guenée) is registered for the first time in tobacco [Nicotiana tabacum L. (Solanaceae)]. The specimens were collected in a Virginia tobacco field, in Venâncio Aires, State of Rio Grande do Sul. Caterpillars occurred in large infestations, causing important damage to tobacco leaves, and demanding chemical control to minimize losses. This occurrence indicates that this species can feed on Virginia tobacco, which corresponds to 80% of the tobacco area of Rio Grande do Sul, and so presents high risk to become an important pest in tobacco fields.

Ocorrência de Rachiplusia nu (Guenée) (Lepidoptera: Noctuidae) em fumo (Nicotiana tabacum L) no Rio Grande do Sul / Occurrence of Rachiplusia nu (Guenée) (Lepidoptera: Noctuidae) on tobacco (Nicotiana tabacum L) in Rio Grande do Sul, Brazil

É registrada pela primeira vez a ocorrência de Rachiplusia nu (Guenée) em Nicotiana tabacum L. (Solanaceae). Os espécimes foram coletados em uma lavoura de fumo tipo Virgínia, em Venâncio Aires, RS. As lagartas ocorreram em grande número, causando expressivo desfolhamento das plantas e demandando controle químico para minimizar os danos. Essa ocorrência indica que R. nu pode se alimentar de fumo, do tipo Virgínia, que ocupa 80 por cento da área cultivada com fumo no Rio Grande do Sul, apresentando, portanto, o risco de se tornar uma praga importante dessa cultura.

The occurrence of Rachiplusia nu (Guenée) is registered for the first time in tobacco [Nicotiana tabacum L. (Solanaceae)]. The specimens were collected in a Virginia tobacco field, in Venâncio Aires, State of Rio Grande do Sul. Caterpillars occurred in large infestations, causing important damage to tobacco leaves, and demanding chemical control to minimize losses. This occurrence indicates that this species can feed on Virginia tobacco, which corresponds to 80 percent of the tobacco area of Rio Grande do Sul, and so presents high risk to become an important pest in tobacco fields.

Chave de identificação, ocorrência e distribuição dos curculionídeos-das-raízes dos citros em São Paulo e Minas Gerais / Key for identification, ocurrence and distribution of citrus root weevils in São Paulo and Minas Gerais, Brazil

O objetivo deste trabalho foi efetuar a diagnose de quatro espécies de curculionídeos-das-raízes que ocorrem nos citros, fornecer uma chave para identificação de 14 espécies, além de estudar sua ocorrência e distribuição na área citrícola dos estados de São Paulo e Minas Gerais. As quatro espécies são registradas pela primeira vez causando danos em citros pertencem ao gênero Naupactus Dejean (Curculionidae; Entiminae; Naupactini): N. bellus Boheman, N. cinerosus Boheman, N. decorus (Fabricius) e N. virens Boheman. Das 14 espécies listadas na chave, onze pertencem ao gênero Naupactus [N. ambiguus Boheman, N. bellus, N. cervinus Boheman, N. cinerosus; N. curtus Boheman, N. decorus, N. navicularis Boheman, N. rivulosus (Olivier), N. tarsalis Boheman, N. versatilis Hustache e N. virens; uma ao gênero Teratopactus Heller (T. nodicollis (Boheman)]; uma ao gênero Parapantomorus Emden [P. fluctuosus (Boheman)] e uma ao gênero Symmathetes (S. kollari Schoenherr). Os curculionídeos-das-raízes foram encontrados em todas as regiões citrícolas dos estados de São Paulo e Minas Gerais sendo a região centro-sul do estado de São Paulo a que apresentou maior número de espécies. N. tarsalis, N. versatilis e P. fluctuosus ocorreram em maior número de municípios.

The objective of this paper is to bring about a diagnosis of four species of root weevils, recorded for the first time causing damage in citrus grooves of the states of São Paulo and Minas Gerais, Brazil. A key for the identification of 14 species harmful for citrus in these states is provided as well as a study on their occurrence and distribution. The four species treated in this paper belong to the genus Naupactus Dejean (Curculionidae: Entiminae: Naupactini): N. bellus Boheman, N. cinerosus Boheman; N. decorus (Fabricius) and N. virens Boheman. Among the 14 species included in the key, eleven belong to Naupactus [N. ambiguus Boheman, N. bellus Boheman, N. cervinus Boheman, N. cinerosus Boheman; N. curtus Boheman, N. decorus (Fabricius), N. navicularis Boheman, N. rivulosus (Olivier), N. tarsalis Boheman, N. versatilis Hustache and N. virens (Boheman); one to Teratopactus Heller (T. nodicollis (Boheman)]; one to Parapantomorus Emden [P. fluctuosus (Boheman)] and one to Symmathetes (S. kollari Schoenherr). The citrus root weevils occur in all citrus grooves of São Paulo and Minas Gerais, and the species diversity is higher in the center-south area of São Paulo. N. tarsalis, N. versatilis and P. fluctuosus are present in the highest number of localities.