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Aim: Laboratory studies were conducted to study the potential of entomopathogenic nematodes and their interaction with the commonly used insecticides viz., clothianidin, imidacloprid and chlorpyriphos against first, second and third instar grubs of H. longipennis and B. coriacea.Methodology: Two entomopathogenic nematodes viz., Heterorhabditis indica Poinar and Steinernema caprocapsae Weiser were tested against I-III instar grubs of Brahmina coriacea (Hope) and Holotrichia longipennis (Blanchard) under laboratory conditions @1600IJs per cup by soil application. The mortality data was recorded after every 24 hrs up to 5 days. For evaluating the interaction effects among different tested biocontrol agents with insecticides, each entomopathogenic nematode species and insecticides was tested alone and in combination. H. indica and S. carpocapsae were applied @ 400IJs per cup. Insecticides were applied at a lower concentrations viz. 150, 100 and 75 ppm for chlorpyriphos, imidacloprid and clothianidin, respectively and were applied on the same day of nematode application with a gap of 2 hrs. Mortality data was taken after 24 hrs. Results: Individual application of H. indica and S. carpocapsae @1600 IJs per cup had clearly lethal effect and produced mortality to the tune of 55.5-90.7 % in both the species of white grubs. H. indica revealed higher virulence as compared to S. carpocapsae against both the species. Combination of both the species with all the tested insecticides yielded synergistic interactions and H. indica+ imidacloprid combination proved to be the most promising among all the tested combinations. Interpretation: Tested entomopathogens and insecticide combination produced synergistic interactions more effectively to first, second and early third instar grubs (H. longipennis and B. coriacea).
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ABSTRACT The first immature description for a South American species of the genus Chlorota Burmeister, 1844 (Melolonthidae: Rutelinae) is presented. The last larval instar and female pupa of Chlorota paulistana Ohaus, 1912 are described. Illustrations and diagnostic characters are also presented, along with additional characters for the genus, and a new state record for Pernambuco is added. With this study, two species of immatures of Chlorota are now known and their diagnostic characters and differences are here discussed.
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Abstract The larva of pentodontine S. laminifer is described for first time based on specimens collected under roots of sugarcane in Santa Cruz, Bolivia. Diagnostic structures are illustrated and the differences and similarities with other previously described larvae of South American genera of Pentodontini are outlined. A key to the larvae of some American genera of pentodontines is included.
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Abstract In Brazil, there are several species of the genus Leucothyreus Macleay, 1819 occurring throughout the country; however, there are only a few studies describing their biological aspects, times of occurrence, associations of adults and juveniles with native or cropped plants, as well as their mating behavior. Thus, this study aimed to assess the mating behavior of Leucothyreus marginaticollis Blanchard, 1843. The study took place in an experimental area of the State University of Mato Grosso do Sul, in Aquidauana, MS, Brazil. Firstly, we sampled adult insects using light traps, from October to November 2013. Simultaneously, we registered the flight period in the field. Afterward, in the laboratory, males and females were separated and then combined into couples for observations of the mating steps. A large number of the adults mated, which lasted on average 22.71 min and occurred from 7 to 11 pm. After mating, part of the males released the females and the other part remained attached to them, which must have happened as an attempt to inhibit other males from mating with them. Moreover, a few females refused to mate with the established male, reinforcing the fact that the pairing of couples occurs after chemical identification among adults. In the field, the largest amount of adults was collected from 8 to 10 pm. Regarding eating habits, adults feed mostly on acerola leaves and flowers (Malpighia emarginata DC, Malpighiaceae), mastic gum leaves (Myracrodruon urundeuva Allemão, Anacardiaceae), grapes (Vitis vinifera L., Vitaceae), apples (Malus domestica Borkh., Rosaceae), and bananas (Musa sp. L., Musaceae). To the end of the experiment, we could clarify the mating steps of L. marginaticollis in order to assist in further extraction and identification of sexual pheromone.
Resumo No Brasil várias são as espécies de Leucothyreus Macleay, 1819 que ocorrem nas diferentes regiões, entretanto, poucos são os trabalhos que descrevem os aspectos biológicos, épocas de ocorrência, associação de adultos e imaturos com plantas nativas ou cultivadas, e comportamento de cópula. Assim o presente trabalho apresentou como objetivo estudar o comportamento de cópula de Leucothyreus marginaticollis Blanchard, 1843. Os estudos foram conduzidos na fazenda experimental da Universidade Estadual de Mato Grosso do Sul em Aquidauana, MS, sendo realizadas coletas de adultos com armadilha luminosa de outubro a novembro de 2013. Com as coletas foram analisados os horários de voo em campo, e em laboratório machos e fêmeas foram separados, posteriormente foram formados casais e as etapas que envolvem o comportamento de cópula, verificadas. Vários adultos realizaram cópula, a qual durou em média 22,71 minutos e ocorreram das 19 às 23 horas. Após a cópula o macho se soltava da fêmea ou permanecia sobre essa, provavelmente para impedir que outro macho realizasse a cópula. Algumas fêmeas não aceitaram os machos para cópula, indicando que a formação de casais ocorre após o reconhecimento químico entre os adultos. O horário de maior coleta dos adultos em campo foi das 20 às 22 horas. Adultos podem se nutrir de folhas e flores de acerola (Malpighia emarginata DC, Malpighiaceae), folhas de aroeira (Myracrodruon urundeuva Allemão, Anacardiacea), frutos de uva (Vitis vinifera L., Vitaceae), maçã (Malus domestica Borkh., Rosaceae) e banana (Musa sp. L., Musaceae), ampliando-se as informações sobre o hábito alimentar dos adultos. Foram elucidadas as etapas relacionadas ao comportamento de cópula de L. marginaticollis, a qual pode auxiliar nos processos de extração e identificação de feromônio sexual.
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ABSTRACT: The scientific and economic importance of soybean root rot justifies the study of this disease, especially the role of insects as dispersers in the spread of root pathogens. The objective was to identify and evaluate qualitatively and quantitatively the role of Cyclocephala modesta, Dyscinetus gagates and Diloboderus abderus (Coleoptera: Melolonthidae ) in the dispersion of root pathogens in cultivated fields. The fungi were identified to the species level with DNA extraction and sequencing of these organisms within Melolonthidae larvae . Larvae were dissected and separated into the parts: mouth parts, prothorax, cuticle and digestive tract (alimentary canal). The Internal Transcribed Spacer region of the rRNA was amplified and compared to sequences deposited in GenBank. This is the first record of dispersion Fusarium oxysporum by Cyclocephala modesta, Dyscinetus gagates and Diloboderus abderus (Coleoptera: Melolonthidae ) under soybean in Brazil.
RESUMO: A importância científica e econômica da podridão radicular da soja justifica o estudo desta doença, especialmente o papel dos insetos como dispersores na disseminação de patógenos radiculares. O objetivo foi identificar e avaliar qualitativa e quantitativamente o papel de Cyclocephala modesta , Dyscinetus gagates e Diloboderus abderus (Coleoptera: Melolonthidae ) na dispersão de patógenos radiculares em campos cultivados. Os fungos foram identificados ao nível de espécie com a extração de DNA e sequenciamento desses organismos dentro de larvas Melolonthidae . As larvas foram dissecadas e separadas em partes: peças bucais, protórax, cutícula e trato digestivo (canal alimentar). A região ITS do RNA ribossômico foi amplificada e comparada com sequências depositadas no GenBank. Este é o primeiro registro da dispersão de Fusarium oxysporum por Cyclocephala modesta , Dyscinetus gagates e Diloboderus abderus (Coleoptera: Melolonthidae ) em cultura de soja no Brasil.
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ABSTRACT Third stage larvae and pupae are described based on specimens collected in Mexico: Oaxaca (Cerro Zempoaltepetl), and Chiapas (Amatenango), respectively. Pupal characters are described for the first time for American Hopliinae. Habitus images and figures of diagnostic characters as well as comments on the differences between these larvae and those of Hoplia callipyge LeConte, 1856 and H. equina LeConte, 1880, the only Hopliinae larvae previously known in New World, are also included.
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Description of the third instar larvae of five species of Cyclocephala (Coleoptera, Melolonthidae, Dynastinae) from Mexico. Larvae of four species of Cyclocephala are described for the first time based on specimens collected in Mexican localities: C. barrerai Martínez, 1969 from Puebla, C. sinaloae Howden & Endrödi, 1966 from Sinaloa, C. fasciolata Bates, 1888 from Veracruz, and C. jalapensis Casey, 1915 from Hidalgo. Larva of C. lunulata Burmeister, 1847, is redescribed based on specimens from the Mexican states of Morelos, Puebla, and Veracruz. Diagnostic structures are illustrated and the differences and similarities of each species with other previously described larvae of the genus are commented.
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Se presentan las descripciones de la larva de tercer estadio de Paranomala flavilla (Bates), P. hoepfneri (Bates) y Strigoderma costulipennis Bates, recolectadas en el estado de Puebla, México, en suelos con cultivo de amaranto (Amaranthus hypochondriacus L.). Se incluyen ilustraciones distintivas y comentarios sobre las diferencias con las larvas de otras especies de los géneros estudiados en México.
The third instar larvae of Paranomala flavilla (Bates), P. hoepfneri (Bates) and Strigoderma costulipennis Bates, collected in Puebla, Mexico, in soils cultivated with amaranth are described. Illustrations of the diagnostic structures and comments on the differences with other larvae of the genera studied in Mexico are included.
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Description of the third larval instar and pupa of Geniates barbatus Kirby (Coleoptera, Scarabaeidae, Rutelinae). The last larval instar and pupa of the Neotropical Geniatini Geniates barbatus Kirby, 1819 are described and illustrated. Biological notes and a key to the third instar larvae of Neotropical Rutelinae are also provided.
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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.
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No Brasil, existem registradas aproximadamente mil espécies de corós, destacando-se, dentre os de maior importância, Diloboderus abderus Sturm, 1826 (Coleoptera: Melolonthidae), pelos prejuízos que pode causar aos cultivos agrícolas e a ampla ocorrência geográfica. O trabalho teve por objetivo caracterizar, com uso da geoestatística, a distribuição espacial de larvas de D. abderus. O estudo foi realizado no ano de 2009, em lavouras de aveia nos municípios de São Francisco de Assis, Cruz Alta e Lagoa Vermelha, RS. Os perímetros das áreas foram demarcados com receptor de sistema de posicionamento global, e os grides de amostragem tiveram dimensão de 70x70m. A densidade populacional foi estimada com abertura de uma trincheira em cada ponto amostral. As análises da variabilidade espacial e da dependência espacial foram feitas por meio de semivariogramas e classificadas segundo CAMBARDELLA et al. (1994). Já os mapas foram gerados a partir dos dados de contagem de larvas em campo. Os semivariogramas indicam a presença de dependência espacial nas áreas de avaliação. Os grides de amostragem mostraram-se apropriados para caracterizar a distribuição espacial de larvas de D. abderus. A distribuição espacial de D. abderus é agregada e seu conhecimento pode melhorar o manejo da praga.
In Brazil, there are about a thousand recorded species of white grubs, and among them the most important is Diloboderus abderus Sturm, 1826 (Coleoptera: Melolonthidae), because of the damage caused to agricultural crops and the wide geographic occurrence. The study aimed to characterize, using geostatistical, the spatial distribution of larvae of D. abderus. The study was conducted during 2009 in oat crops in the counties of São Francisco de Assis, Cruz Alta and Lagoa Vermelha, RS. The perimeters of the fields were delimited with global positioning system receptor, and the sampling grids dimensions were 70x70m. The population density was estimated by opening a trench in each sampling point. The analysis of spatial variability and spatial dependence were made by semivariograms and classified from CAMBARDELLA et al. (1994). Maps were generated from the counting data of larvae in the field. The semivariograms indicate the presence of spatial dependence in the assessment areas. The sampling grids proved to be suitable to characterize the spatial distribution of D. abderus larvae. The spatial distribution of D. abderus is aggregated and this knowledge may improve pest management.
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No Brasil existe uma escassez de informações sobre a bioecologia da maioria das espécies de Scarabaeidae. O objetivo do presente trabalho foi estudar os aspectos biológicos de Leucothyreus dorsalis Blanchard, 1850 em laboratório e a campo. A dinâmica populacional dos adultos foi avaliada de janeiro de 2006 a dezembro de 2007, com uso de armadilha luminosa. Adultos coletados em campo foram mantidos em recipientes de plástico contendo solo e mudas de Brachiaria decumbens Stapf, para obtenção de ovos e dar início aos estudos. Todos os estágios de desenvolvimento foram acompanhados e adultos e imaturos foram mensurados para obtenção de dados biométricos. Foram coletados 3.607 adultos e os picos populacionais de coleta ocorreram em novembro de 2006 e outubro de 2007, com média de 145 e 241 indivíduos coletados, respectivamente. O período embrionário durou em média 15,5 dias, o primeiro instar 32,4 dias, o segundo 38,9 dias, o terceiro 52,7 dias, a fase de pré-pupa 130,7 dias, a fase pupal 23,5 dias e a longevidade 18 dias. O ciclo biológico completou-se em 273,5 dias, o que caracteriza a espécie como univoltina. Verificou-se que do primeiro ao terceiro instar houve um aumento de 4,5 vezes no comprimento e de 3,5 vezes na largura das larvas. Observou-se um aumento de 53,1 vezes no peso larval do primeiro para o terceiro instar. As pupas das fêmeas foram significativamente maiores e mais pesadas que a dos machos. As fêmeas adultas foram maiores que os adultos machos, porém, apresentaram peso semelhante.
In Brazil there is a shortage of information on bioecology of most species of Scarabaeidae. The aim of this work was to study the biological aspects of Leucothyreus dorsalis Blanchard, 1850 in laboratory and field. The population dynamics of adults was evaluated from January, 2006, to December, 2007, with the use of light traps. Adults collected in the field were kept in plastic recipients containing soil and seedlings of Brachiaria decumbens Stapf, to obtain eggs and start the studies. All developmental stages were monitored and adults and immatures measured to get biometric data. 3,607 adults were collected and the population peaks occurred in November, 2006 and October, 2007, with averages of 145 e 241 individuals collected, respectively. The embryonic period took in the average 15.5 days, the 1st instar 32.4 days, the 2nd instar 38.9 days, the 3rd instar 52.7 days, the pre-pupa 130.7 days, the pupa 23.5 days and the longevity of adults 18 days. The biological cycle was completed in 273.5 days, characterizing the specie as univoltine. From the first to the third instar it was observed an increasing of 4.5 times in the extension and 3.5 times in the width of the larvae. There was an increase of 53.1 times in the larval weight from the first to the third instar. The female pupae were significantly larger and heavier than the male ones. The adult females are larger than the adult males, however, they have similar weight.
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Due to the importance of some Pleurosticti Scarabaeidae as agricultural pests allied to information absence on the species that occur in Brazilian Central-West region, on studies occurrence, biology and behavior on this group of scarabs were conducted. Biology and behavioral studies started with Liogenys fuscus Blanchard, 1850 (Melolonthinae), a very common species and were developed in Aquidauana, Mato Grosso do Sul. Adult beetles were collected from light traps from February 2005 to January 2007, at the experimental farm of the Universidade Estadual de Mato Grosso do Sul in Aquidauana (UEMS). In the laboratory adults were placed in plastic containers with soil with sprouts of Brachiaria decumbens Stapf (Poaceae). Eggs were transferred to a climatized chamber at 26 ± 1º C with a 12hourlight, 12hour darkness photoperiod cycle. Adult flight activity occurred in August and in September to December from 06:00 pm to 06:00 am, with the largest number of individuals flying from 07:00 to 10:00 pm. Eggs measured 1 x 1.5 mm and were laid individually or in groups in soil chambers; eggs were initially white and became yellow near hatching. The embryonic period lasted 14.3 days; first, second and third instars lasted 28.5, 48.8, and 68.2 days, respectively. The prepupal period lasted 120.2 days and the prepupa stayed inactive in soil. The mean duration of pupal stage was 27.5 days and the mean longevity of adults was 23.6 days. In laboratory the calling behavior between males and females was observed; copulation lasted, in mean, 25 minutes.
Devido à importância de alguns Scarabaeidae Pleurosticti como causadores de danos à agricultura, aliada à ausência de informações sobre as espécies que ocorrem na região Centro Oeste, foram desenvolvidos estudos sobre a ocorrência, biologia e comportamento sobre este grupo de escarabeídeos. Foram iniciados com Liogenys fuscus Blanchard, 1850 (Melolonthinae), espécie muito comum em Aquidauana, Mato Grosso do Sul, Brasil. Na fazenda experimental da Universidade Estadual de Mato Grosso do Sul (UEMS), campus de Aquidauana, foi instalada diariamente, armadilha luminosa, de fevereiro de 2005 a janeiro de 2007 para coleta dos adultos. Os adultos coletados foram encaminhados para laboratório e acondicionados em caixas de plástico, contendo solo e mudas de Brachiaria decumbens Stapf (Poaceae). Foi possível obter ovos e realizar os estudos de biologia, em câmara climatizada a 26 ± 1º C e fotofase de 12 horas. Os adultos revoaram entre agosto e setembro a dezembro nos dois anos de estudos, nos horários das 18h00 às 6h00, em maior quantidade das 19h00 às 22h00. Os ovos, de 1,5 x 1,0 mm, foram depositados no solo individualmente ou agrupados em câmaras; possuem coloração branca e quando estão próximos da eclosão adquirem cor amarela. O período embrionário durou 14,3 dias, o primeiro, segundo e terceiro instares duraram 28,5, 48,8 e 68,2 dias respectivamente. O período de prépupa, que permaneceu inativa no solo, durou 120,2 dias. A fase de pupa durou em média de 27,5 dias e os adultos apresentaram longevidade média de 23,6 dias. Em laboratório foi observado comportamento de chamamento entre machos e fêmeas e a cópula durou em média 25 minutos.