Resumo
Many gall-inducing insects have been reported as pests in the Old World and North America, although few such examples are known from South America. A list of gall-inducing insects of potential economic importance, with a focus on those of restinga environments, was compiled using Maia (2013a) as starting point and updated with the database Thompson ISI, using Insect (title) and gall (topic) as keywords. Botanical names were updated using the site Flora do Brasil, 2020, while potential economic significance of host plant species was acquired from Santos et al. (2009) and the site Useful Tropical Plants. Fifty-eight galling species were associated with 29 economically important plant species of 18 families in Brazilian restingas. The gallers were found to belong to Diptera (Cecidomyiidae and Agromyzidae) and Hemiptera (Eriococcidae and Psyllidae), among which Cecidomyiidae were the most important, with 55 gall-inducing species distributed among 28 genera. Six of the found genera are endemic to the Atlantic Forest and, until now, have been exclusively reported in restingas. About 78% of the gallers have been recorded only in Southeast Brazil and about 64% only in the state of Rio de Janeiro. Most gallers were found to be mainly associated with edible and/or medicinal plant species. Data on natural enemies are scarce with most records having been published at the taxonomic level of family or genus. Natural enemies were found associated with 43 gall-inducing species and included parasitoids, predators and inquilines. The first were the most diverse, being represented by 13 hymenopteran families, but the impacts of all of these guilds on galler populations are poorly known. Although 58 gall-inducing species were identified in the present study, the number of insect galls associated with plants of economic interests in restinga environments is about three times greater, since a total of 186 gall morphotypes have been reported. Nonetheless...
Resumo
Many gall-inducing insects have been reported as pests in the Old World and North America, although few such examples are known from South America. A list of gall-inducing insects of potential economic importance, with a focus on those of restinga environments, was compiled using Maia (2013a) as starting point and updated with the database Thompson ISI, using Insect (title) and gall (topic) as keywords. Botanical names were updated using the site Flora do Brasil, 2020, while potential economic significance of host plant species was acquired from Santos et al. (2009) and the site Useful Tropical Plants. Fifty-eight galling species were associated with 29 economically important plant species of 18 families in Brazilian restingas. The gallers were found to belong to Diptera (Cecidomyiidae and Agromyzidae) and Hemiptera (Eriococcidae and Psyllidae), among which Cecidomyiidae were the most important, with 55 gall-inducing species distributed among 28 genera. Six of the found genera are endemic to the Atlantic Forest and, until now, have been exclusively reported in restingas. About 78% of the gallers have been recorded only in Southeast Brazil and about 64% only in the state of Rio de Janeiro. Most gallers were found to be mainly associated with edible and/or medicinal plant species. Data on natural enemies are scarce with most records having been published at the taxonomic level of family or genus. Natural enemies were found associated with 43 gall-inducing species and included parasitoids, predators and inquilines. The first were the most diverse, being represented by 13 hymenopteran families, but the impacts of all of these guilds on galler populations are poorly known. Although 58 gall-inducing species were identified in the present study, the number of insect galls associated with plants of economic interests in restinga environments is about three times greater, since a total of 186 gall morphotypes have been reported. Nonetheless...(AU)
Resumo
La más compleja de las interacciones que plantas e insectos han desarrollado durante el transcurso de su evolución, son las agallas. Las especies de insectos galícolas se encuentran en la mayoría de las regiones biogeográficas, principalmente en ambientes xéricos, de los cuales un ejemplo lo constituye la ecorregión del Espinal, ubicada en la Provincia Biogeográfica de la Pampa, Subregión Chaqueña. Schinus fasciculata (Griseb.) I.M. Johnst. (Anacardiaceae) es una especie arbórea o arbustiva representativa de la ecorregión del Espinal que presenta diversas agallas entomógenas. Los objetivos del presente trabajo son identificar las especies de insectos que producen agallas en hojas y tallos de Schinus fasciculata en un relicto de Espinal de la provincia de Córdoba y caracterizar exomorfológicamente las agallas. Se seleccionaron 18 ejemplares de S. fasciculata distribuidos en cuatro transectas de 100 m2. Se caracterizaron cinco morfotipos de agallas, tres en hojas, inducidas por insectos del orden Hemiptera y dos en tallos, originadas por insectos del orden Lepidoptera. Los insectos productores de las mismas fueron identificados a nivel de especie y los distintos morfotipos de agallas fueron únicos para cada especie de insecto inductor(AU)
Galls are the most complex interaction between plants and insects during the course of their evolution. The species of galling insects are found in the most of biogeographic regions, but mainly in xeric habitats, as the Espinal eco-region, located in the Pampa Biogeographic Region, Chacoan Subregion. Schinus fasciculata (Griseb.) I. M. Johnst. (Anacardiaceae) it is a tree or shrub, representative from the Espinal eco-region, which supports several kinds of galls. Our objectives are to identify the insect species that induce leaves and stem galls on Schinus fasciculata, in an Espinal relict from province of Córdoba and to describe the exomorphology of galls. In this Espinal relict 18 plants of Schinus fasciculata, in four transects of 100 m2 were selected. Five morphological types of galls were found, three on leaves, induced by insects belonging to Hemiptera Order, and two on stems, induced by insects of Lepidoptera Order. The galling insects were identified at species level and the different morphotypes of galls found were unique to each galling insect species(AU)
Assuntos
Animais , Anacardiaceae , Tumores de Planta , Hemípteros , Lepidópteros , InsetosResumo
La más compleja de las interacciones que plantas e insectos han desarrollado durante el transcurso de su evolución, son las agallas. Las especies de insectos galícolas se encuentran en la mayoría de las regiones biogeográficas, principalmente en ambientes xéricos, de los cuales un ejemplo lo constituye la ecorregión del Espinal, ubicada en la Provincia Biogeográfica de la Pampa, Subregión Chaqueña. Schinus fasciculata (Griseb.) I.M. Johnst. (Anacardiaceae) es una especie arbórea o arbustiva representativa de la ecorregión del Espinal que presenta diversas agallas entomógenas. Los objetivos del presente trabajo son identificar las especies de insectos que producen agallas en hojas y tallos de Schinus fasciculata en un relicto de Espinal de la provincia de Córdoba y caracterizar exomorfológicamente las agallas. Se seleccionaron 18 ejemplares de S. fasciculata distribuidos en cuatro transectas de 100 m2. Se caracterizaron cinco morfotipos de agallas, tres en hojas, inducidas por insectos del orden Hemiptera y dos en tallos, originadas por insectos del orden Lepidoptera. Los insectos productores de las mismas fueron identificados a nivel de especie y los distintos morfotipos de agallas fueron únicos para cada especie de insecto inductor
Galls are the most complex interaction between plants and insects during the course of their evolution. The species of galling insects are found in the most of biogeographic regions, but mainly in xeric habitats, as the Espinal eco-region, located in the Pampa Biogeographic Region, Chacoan Subregion. Schinus fasciculata (Griseb.) I. M. Johnst. (Anacardiaceae) it is a tree or shrub, representative from the Espinal eco-region, which supports several kinds of galls. Our objectives are to identify the insect species that induce leaves and stem galls on Schinus fasciculata, in an Espinal relict from province of Córdoba and to describe the exomorphology of galls. In this Espinal relict 18 plants of Schinus fasciculata, in four transects of 100 m2 were selected. Five morphological types of galls were found, three on leaves, induced by insects belonging to Hemiptera Order, and two on stems, induced by insects of Lepidoptera Order. The galling insects were identified at species level and the different morphotypes of galls found were unique to each galling insect species
Assuntos
Animais , Anacardiaceae , Hemípteros , Lepidópteros , Tumores de Planta , InsetosResumo
In Brazil the knowledge about the geographical distribution and host plants of whiteflies (Hemiptera: Aleyrodidae) is limited, mainly on crops. In this communication, the occurrence of Aleurodicus mirabilis (Cockerell, 1898) in high infestations in custard apple (Annona squamosa Linnaeus, 1753) is recorded in the state of São Paulo, Brazil.
No Brasil, é restrito o conhecimento sobre distribuição geográfica e plantas hospedeiras de moscas-brancas (Hemiptera: Aleyrodidae), principalmente em plantas cultivadas. Nesta comunicação, é registrada a ocorrência de Aleurodicus mirabilis (Cockerell, 1898) em altas infestações em fruta-do-conde (Annona squamosa Linnaeus, 1753) no estado de São Paulo, Brasil.
Resumo
In Brazil the knowledge about the geographical distribution and host plants of whiteflies (Hemiptera: Aleyrodidae) is limited, mainly on crops. In this communication, the occurrence of Aleurodicus mirabilis (Cockerell, 1898) in high infestations in custard apple (Annona squamosa Linnaeus, 1753) is recorded in the state of São Paulo, Brazil.
No Brasil, é restrito o conhecimento sobre distribuição geográfica e plantas hospedeiras de moscas-brancas (Hemiptera: Aleyrodidae), principalmente em plantas cultivadas. Nesta comunicação, é registrada a ocorrência de Aleurodicus mirabilis (Cockerell, 1898) em altas infestações em fruta-do-conde (Annona squamosa Linnaeus, 1753) no estado de São Paulo, Brasil.
Resumo
In Brazil the knowledge about the geographical distribution and host plants of whiteflies (Hemiptera: Aleyrodidae) is limited, mainly on crops. In this communication, the occurrence of Aleurodicus mirabilis (Cockerell, 1898) in high infestations in custard apple (Annona squamosa Linnaeus, 1753) is recorded in the state of São Paulo, Brazil.
No Brasil, é restrito o conhecimento sobre distribuição geográfica e plantas hospedeiras de moscas-brancas (Hemiptera: Aleyrodidae), principalmente em plantas cultivadas. Nesta comunicação, é registrada a ocorrência de Aleurodicus mirabilis (Cockerell, 1898) em altas infestações em fruta-do-conde (Annona squamosa Linnaeus, 1753) no estado de São Paulo, Brasil.
Resumo
Eighteen species from seven genera are recorded from the Amazon River floodplain, Brazil. An identification key, diagnoses, drawings, and taxonomic and biological notes are given for these species. The main features used in the identification key and diagnoses are: body and leg segments proportions, coloration patterns, presence and distribution of setae, and modifications of the apical abdominal segments and external genitalia of the male. Based on material collected in the floodplain streams and lakes, Cylindrostethus bassleri Drake, 1952 is recorded for the first time from Brazil, and new municipality records are presented for Brachymetra lata Shaw, 1933, B. shawi Hungerford & Matsuda, 1957, C. erythropus (Herrich-Schäffer, 1850), C. linearis (Erichson, 1848), C. Palmaris Drake & Harris, 1934, C. regulus (White, 1879), Neogerris lotus (White, 1879), N. lubricus (White, 1879), N. visendus (Drake & Harris, 1934), Ovatametra obese Kenaga, 1942, Rheumatobates crassifemur esakii Schroeder, 1931, R. klagei Schroeder, 1931, and Trepobates taylori (Kirkaldy, 1899). Additional new records from the Brazilian Amazon are presented for B. lata and O. obesa.
Resumo
Eighteen species from seven genera are recorded from the Amazon River floodplain, Brazil. An identification key, diagnoses, drawings, and taxonomic and biological notes are given for these species. The main features used in the identification key and diagnoses are: body and leg segments proportions, coloration patterns, presence and distribution of setae, and modifications of the apical abdominal segments and external genitalia of the male. Based on material collected in the floodplain streams and lakes, Cylindrostethus bassleri Drake, 1952 is recorded for the first time from Brazil, and new municipality records are presented for Brachymetra lata Shaw, 1933, B. shawi Hungerford & Matsuda, 1957, C. erythropus (Herrich-Schäffer, 1850), C. linearis (Erichson, 1848), C. Palmaris Drake & Harris, 1934, C. regulus (White, 1879), Neogerris lotus (White, 1879), N. lubricus (White, 1879), N. visendus (Drake & Harris, 1934), Ovatametra obese Kenaga, 1942, Rheumatobates crassifemur esakii Schroeder, 1931, R. klagei Schroeder, 1931, and Trepobates taylori (Kirkaldy, 1899). Additional new records from the Brazilian Amazon are presented for B. lata and O. obesa.
Resumo
Eighteen species from seven genera are recorded from the Amazon River floodplain, Brazil. An identification key, diagnoses, drawings, and taxonomic and biological notes are given for these species. The main features used in the identification key and diagnoses are: body and leg segments proportions, coloration patterns, presence and distribution of setae, and modifications of the apical abdominal segments and external genitalia of the male. Based on material collected in the floodplain streams and lakes, Cylindrostethus bassleri Drake, 1952 is recorded for the first time from Brazil, and new municipality records are presented for Brachymetra lata Shaw, 1933, B. shawi Hungerford & Matsuda, 1957, C. erythropus (Herrich-Schäffer, 1850), C. linearis (Erichson, 1848), C. Palmaris Drake & Harris, 1934, C. regulus (White, 1879), Neogerris lotus (White, 1879), N. lubricus (White, 1879), N. visendus (Drake & Harris, 1934), Ovatametra obese Kenaga, 1942, Rheumatobates crassifemur esakii Schroeder, 1931, R. klagei Schroeder, 1931, and Trepobates taylori (Kirkaldy, 1899). Additional new records from the Brazilian Amazon are presented for B. lata and O. obesa.
Resumo
Based on material collected on streams and lakes from the Amazon River floodplain, Brazil, Microvelia urucara sp. nov. is described, illustrated and compared with similar species. The new species, like many other Neotropical Microvelia Westwood, 1834, does not present striking modifications on the body or appendages, but can be separated from its congeners by features of the male genitalia. Distributional data is presented for other veliids collected along the Amazon River, and Paravelia capixaba Moreira, Nessimian & Rúdio, 2010 and Microvelia summersi Drake & Harris, 1928 are recorded for the first time from the Brazilian Amazon. Rhagovelia jubata Bacon, 1948 is newly recorded from the state of Amazonas, and Microvelia mimula White, 1879, M. pulchella Westwood, 1834 and M. venustatis Drake & Harris, 1933 are recorded for the first time from the state of Pará.
Resumo
Based on material collected on streams and lakes from the Amazon River floodplain, Brazil, Microvelia urucara sp. nov. is described, illustrated and compared with similar species. The new species, like many other Neotropical Microvelia Westwood, 1834, does not present striking modifications on the body or appendages, but can be separated from its congeners by features of the male genitalia. Distributional data is presented for other veliids collected along the Amazon River, and Paravelia capixaba Moreira, Nessimian & Rúdio, 2010 and Microvelia summersi Drake & Harris, 1928 are recorded for the first time from the Brazilian Amazon. Rhagovelia jubata Bacon, 1948 is newly recorded from the state of Amazonas, and Microvelia mimula White, 1879, M. pulchella Westwood, 1834 and M. venustatis Drake & Harris, 1933 are recorded for the first time from the state of Pará.
Resumo
Based on material collected on streams and lakes from the Amazon River floodplain, Brazil, Microvelia urucara sp. nov. is described, illustrated and compared with similar species. The new species, like many other Neotropical Microvelia Westwood, 1834, does not present striking modifications on the body or appendages, but can be separated from its congeners by features of the male genitalia. Distributional data is presented for other veliids collected along the Amazon River, and Paravelia capixaba Moreira, Nessimian & Rúdio, 2010 and Microvelia summersi Drake & Harris, 1928 are recorded for the first time from the Brazilian Amazon. Rhagovelia jubata Bacon, 1948 is newly recorded from the state of Amazonas, and Microvelia mimula White, 1879, M. pulchella Westwood, 1834 and M. venustatis Drake & Harris, 1933 are recorded for the first time from the state of Pará.
Resumo
The egg parasitoid Erythmelus tingitiphagus (Soares) is one of the main natural enemies of lace bug Leptopharsa heveae Drake & Poor (Hemiptera: Tingidae), together with the green lacewings and the fungus Sporothrix insectorum (Hoog e Evans). Studies about insect-pest distribution and their natural enemies in rubber tree are scarce. The objective of this research was to verify the sazonal horizontal distribution and population fluctuation of the parasitoid E. tingitiphagus in commercial blocks of rubber tree of the clones RRIM 600, PR 255, PB 217, PB 235 and GT 1, from october of 2005 to february of 2006, period of occurrence of L. heveae in the studied area. The samplings were performed in the North, South, East and West quadrants of five blocks, Ripe leaves of the inferior third of the canopy of five marked trees, from the edge towards the interior of the blocks, were collected. The leaves were taken to the laboratory, washed in sodium hypochlorite solution (1.5%), rinsed and dried under absorbent paper. The petioles of each leaflet were inserted in plastic tubes containing water, sealed, conditioned in identified plastic bags (12 x 30 cm), filled with an air compressor and closed in electric stamp. The material was suspended in clothes lines in an acclimatized room at 25 ± 1 ºC and 12 hours of photoperiod. After five days, the bags and leaflets were observed under stereos
O parasitóide de ovos Erythmelus tingitiphagus (Soares) é um dos principais inimigos naturais do percevejo-de-renda, Leptopharsa heveae Drake e Poor (Hemiptera: Tingidae), juntamente com os crisopídeos e o fungo Sporothrix insectorum (Hoog e Evans). Estudos sobre a distribuição de insetospraga e seus inimigos naturais em seringueira são escassos. Neste sentido, o objetivo desta pesquisa foi verificar a distribuição horizontal sazonal e a flutuação populacional do parasitóide E. tingitiphagus em talhões comerciais dos clones de seringueira RRIM 600, PR 255, PB 217, PB 235 e GT 1, no período de outubro de 2005 a fevereiro de 2006, período de ocorrência de L.heveae na região estudada. As amostragens foram realizadas nos quadrantes Norte, Sul, Leste e Oeste de cinco talhões, em folhas maduras coletadas no terço inferior da copa de cinco árvores marcadas, da bordadura em direção ao interior dos talhões. As folhas foram levadas ao laboratório, lavadas em solução de hipoclorito de sódio (1,5%), enxaguadas e secadas sobre papel absorvente. Os pecíolos de cada folíolo foram inseridos em tubos plásticos contendo água, lacrados, acondicionados em sacos plásticos (12 x 30 cm) identificados, inflados com auxílio de um compressor de ar e fechados em seladora elétrica. O material foi pendurado em varais em sala climatizada a 25 ± 1 ºC com fotofase de 12 horas. Após cinco dias, os sacos e folí
Resumo
The silverleaf whitefly Bemisia tabaci (Genn.) B-biotype (= B. argentifolii) (Hemiptera: Aleyrodidae) is a polyphagous insect attacking many plant species of economic importance. A comparison study was conducted on the duration of the egg-to-adult period, and the percentage of hatching eggs of Bemisia tabaci (Genn.) B-biotype on collard (Brassica oleracea L. var. acephala D.C.), soybean(Glycine max (L.) Merr.) and tomato (Lycopersicon esculentum Mill.) plants, as well as the egg-to-adult period of Encarsia formosa (Gahan) on the 1st, 2nd, 3rd and 4th whitefly nymphal instars on these three plant species. The experiments were conducted in a laboratory (25ºC, 70 ± 10% RH, 14-hour photophase). The duration of the egg-to-adult period of B. tabaci was 19.8 days on collard, 21.2 days on soybean and 22.0 days on tomato. The number of hatched eggs was higher on collard when compared to soybean and tomato plants. Concerning E. formosa regardless of plant species, the duration for the egg-to-adult period was shorter for the 3rd and 4th instar nymphs as compared with the other instars.
A mosca branca Bemisia tabaci (Genn.) biótipo B é uma praga polífaga que ataca muitas culturas de importância econômica. O controle químico pode causar problemas como o aparecimento de resistência nesse inseto, resíduos nos produtos das culturas, ou mesmo poluição ambiental. Um método alternativo seria o controle biológico, com o parasitóide Encarsia formosa (Gahan), o mais usado contra moscas brancas a nível mundial. Avaliaram-se o tempo de desenvolvimento de ovo a adulto e a porcentagem de ninfas eclodidas de B. tabaci (Genn.) biótipo B em couve (Brassica oleracea L. var. acephala D.C.), soja (Glycine max (L.) Merr.) e tomateiro (Lycopersicon esculentum Mill.), bem como o desenvolvimento de ovo a adulto de E. formosa em ninfas de 1º, 2º, 3º e 4º ínstares dessa mosca-branca nessas três espécies vegetais. Os experimentos foram desenvolvidos em laboratório, a 25ºC, 70 ± 10% UR e 14 h de fotofase. O tempo de duração ovo-adulto de B. tabaci biótipo B foi mais curto em couve (19,8 dias) e mais longo em tomateiro (22,0 dias), ficando a soja (21,2 dias) em posição intermediária. A couve mostrou também a maior porcentagem de ninfas eclodidas comparativamente à soja e ao tomateiro. Com relação a E. formosa, independentemente da planta, o período ovo-adulto foi menor em ninfas de 3º e 4º ínstares, demonstrando que esse parasitóide se desenvolve melhor em ninfas mais desenvolvidas.
Resumo
The silverleaf whitefly Bemisia tabaci (Genn.) B-biotype (= B. argentifolii) (Hemiptera: Aleyrodidae) is a polyphagous insect attacking many plant species of economic importance. A comparison study was conducted on the duration of the egg-to-adult period, and the percentage of hatching eggs of Bemisia tabaci (Genn.) B-biotype on collard (Brassica oleracea L. var. acephala D.C.), soybean(Glycine max (L.) Merr.) and tomato (Lycopersicon esculentum Mill.) plants, as well as the egg-to-adult period of Encarsia formosa (Gahan) on the 1st, 2nd, 3rd and 4th whitefly nymphal instars on these three plant species. The experiments were conducted in a laboratory (25ºC, 70 ± 10% RH, 14-hour photophase). The duration of the egg-to-adult period of B. tabaci was 19.8 days on collard, 21.2 days on soybean and 22.0 days on tomato. The number of hatched eggs was higher on collard when compared to soybean and tomato plants. Concerning E. formosa regardless of plant species, the duration for the egg-to-adult period was shorter for the 3rd and 4th instar nymphs as compared with the other instars.
A mosca branca Bemisia tabaci (Genn.) biótipo B é uma praga polífaga que ataca muitas culturas de importância econômica. O controle químico pode causar problemas como o aparecimento de resistência nesse inseto, resíduos nos produtos das culturas, ou mesmo poluição ambiental. Um método alternativo seria o controle biológico, com o parasitóide Encarsia formosa (Gahan), o mais usado contra moscas brancas a nível mundial. Avaliaram-se o tempo de desenvolvimento de ovo a adulto e a porcentagem de ninfas eclodidas de B. tabaci (Genn.) biótipo B em couve (Brassica oleracea L. var. acephala D.C.), soja (Glycine max (L.) Merr.) e tomateiro (Lycopersicon esculentum Mill.), bem como o desenvolvimento de ovo a adulto de E. formosa em ninfas de 1º, 2º, 3º e 4º ínstares dessa mosca-branca nessas três espécies vegetais. Os experimentos foram desenvolvidos em laboratório, a 25ºC, 70 ± 10% UR e 14 h de fotofase. O tempo de duração ovo-adulto de B. tabaci biótipo B foi mais curto em couve (19,8 dias) e mais longo em tomateiro (22,0 dias), ficando a soja (21,2 dias) em posição intermediária. A couve mostrou também a maior porcentagem de ninfas eclodidas comparativamente à soja e ao tomateiro. Com relação a E. formosa, independentemente da planta, o período ovo-adulto foi menor em ninfas de 3º e 4º ínstares, demonstrando que esse parasitóide se desenvolve melhor em ninfas mais desenvolvidas.
Resumo
O pulgão Myzus persicae (Sulzer) é considerado praga-chave da cultura da batata inglesa, cuja produtividade depende do uso de inseticidas para o seu controle. Este trabalho foi conduzido para verificar o efeito do silício e do imidaclopride na colonização de plantas por M. persicae e seus possíveis reflexos positivos no desenvolvimento da batata inglesa. Foram testados cinco tratamentos, com sete repetições: 1- testemunha; 2- ácido silícico a 1 por cento; 3- imidacloprid na dosagem recomendada (252g ha-1); 4- ácido silícico a 1 por cento e imidacloprid na metade da dosagem recomendada (126g ha-1); e 5- imidaclopride na metade da dosagem recomendada (126g ha-1). Após 20 dias do plantio, as plantas (cv. Emeraude) foram infestadas com dez pulgões adultos. Avaliaram-se, após 20 dias da infestação, o número de ninfas e de adultos de pulgões, a altura, o diâmetro, o número de folhas e a fitomassa fresca e seca das plantas. As plantas tratadas com o inseticida foram pouco colonizadas pelos pulgões e aquelas tratadas com silício apresentaram menor infestação em relação à testemunha. Em relação à altura, ao diâmetro e à fitomassa, não houve diferença significativa entre os tratamentos, porém a testemunha apresentou menor número de folhas. Assim, o silício diminuiu a colonização da batata por M. persicae e o uso da metade da dosagem recomendada de imidacloprid (126g ha-1) foi igualmente eficiente para impedir a colonização, tornando a adubação silicatada mais uma tática a ser testada no manejo integrado de pragas da batateira.(AU)
The aphid Myzus persicae (Sulzer) is a key pest of potato crops, the yield of which depends on insecticides for its control. This research was carried out to verify the effect of silicon and imidacloprid on the colonization of potato plants by M. persicae and its possible positive consequences on development parameters. Five treatments with seven replications were tested: 1- control treatment; 2- 1 percent silicic acid; 3- imidacloprid at the recommended dosage (252g ha-1); 4- 1 percent silicic acid and imidacloprid at half recommended dosage (126g ha-1) and 5- imidacloprid at half the recommended dosage (126g ha-1). Twenty days after planting, the plants were infested with ten adult aphids. After 20 days of infestation, the number of nymphs and of adult aphids; the height, the diameter, the number of leaves and the fresh and dried weights of the plants were evaluated. The plants treated with insecticides were not so colonized by the aphids and those with silicon presented lower infestation in relation to the control. In relation to the height, diameter and weights, there was no significant difference among the treatments, however the control presented the lowest number of leaves. Therefore, silicon reduced the colonization of potato by M. persicae and the use of half dosage of imidacloprid (126g ha-1) was equally efficient to prevent the colonization, making silicated fertilization one more strategy to be tested in the integrated management of potato plant pests.(AU)
Assuntos
AfídeosResumo
Three new neotropical species of the spittlebug genus Mahanarva are described: M. (M.) rubrovenata, M. (M.) webbi e M. (M.) dabliosignata, all from Brazil.
Três novas espécies de cigarrinhas neotropicais do gênero Mahanarva são descritas: M. (M.) rubrovenata, M. (M.) webbi e M. (M.) dabliosignata, todas do Brasil.
Resumo
Three new neotropical species of the spittlebug genus Mahanarva are described: M. (M.) rubrovenata, M. (M.) webbi e M. (M.) dabliosignata, all from Brazil.
Três novas espécies de cigarrinhas neotropicais do gênero Mahanarva são descritas: M. (M.) rubrovenata, M. (M.) webbi e M. (M.) dabliosignata, todas do Brasil.
Resumo
Bemisia tabaci B biotype (whitefly) has been responsible for many losses on tomatoes, mainly due to irregular ripening of the fruits and decrease on yield potential. The aim of this study was to evaluate the effect of different potassium sources (K-sources), fertirrigated by drip irrigation system, on the infestation of B. tabaci B biotype and on the sugar content on the leaves of three different tomato cultivars.The experiment was carried out on greenhouse at the Experimental Station of the Instituto Agronômico (IAC), São Paulo, Brazil, between September 2000 and January 2001. Potassium Chlorate (KCl) and Potassium Sulphate (K 2 SO 4 ) were used as K-sources. Sweet Million, Rocio and Densus were the selected cultivars. Plants were cultivated on slabs filled with agricultural substratum and fertirrigated with nutritive solution. Evaluated parameters were: number of eggs and nymphs on the plants at 20 and 40 days after whitefly infestation; and reducing sugars, sucrose and total sugars on the leaves. Results showed that K-sources did not have influence on the number of eggs and nymphs. On the second evaluation date, cultivar effect was significant on oviposition. Leaf sugar content were influenced by K-sources. Tomato plants fertirrigated with K 2 SO 4 on nutritive solution presented higher values, for total sugar content on the leaves, in comparison with the plants treated with
A mosca branca Bemisia tabaci biótipo B é um inseto que tem causado inúmeros prejuízos ao tomateiro, principalmente devido ao amadurecimento irregular dos frutos e diminuição do potencial produtivo. Assim, objetivou-se estudar o efeito da aplicação de sulfato e cloreto de potássio, via fertirrigação por gotejamento, na infestação B. tabaci biótipo B e os teores de açúcares nas folhas de tomateiro. O experimento foi conduzido em estufa plástica no Núcleo Experimental de Campinas (IAC) em Campinas, São Paulo, no período de setembro de 2000 a janeiro de 2001. Utilizou-se cloreto de potássio (KCl) e sulfato de potássio (K 2 SO 4 ) como fontes de potássio e três cultivares de tomateiro, Sweet Million, Rocio e Densus. Estas três cultivares foram cultivadas em slabs contendo substrato agrícola e fertirrigadas com solução nutritiva. Foram avaliados o número de ovos e ninfas de mosca branca nas plantas de tomateiro em duas épocas distintas, aos 20 e 40 dias após a infestação com moscas brancas. Avaliaram-se também, açúcares redutores, sacarose e açúcares totais das folhas de tomateiro. Verificou-se que as fontes de potássio não influenciaram no número de ovos + ninfas de mosca branca. Porém, nas avaliações realizadas na segunda época de amostragem, verificou-se influência varietal sobre a oviposição da mosca branca. Já os açúcares contidos nas folhas de tomateiro foram influênciados p