O estudo foi conduzido para avaliar a seletividade de oito formulações de glyphosate (Roundup®, Roundup® WG, Roundup® Transorb, Polaris®, Gliz® 480 CS, Glifosato Nortox®, Glifosato 480 Agripec® e Zapp® Qi) registradas no Brasil sobre o parasitóide de ovos Trichogramma pretiosum (Hym., Trichogrammatidae). Os experimentos consistiram na exposição de adultos do parasitóide a resíduos secos das formulações pulverizadas sobre placas de vidro, na concentração de 14,4 mg L-1 de equivalente ácido de glyphosate. O tratamento controle recebeu água destilada. Ovos do hospedeiro alternativo Anagasta kuehniella (Lep., Pyralidae) foram ofertados para parasitismo. A capacidade de parasitismo por fêmea de T. pretiosum e a redução na capacidade, comparada com o tratamento controle, foram utilizadas para estimar a toxicidade do produto. As formulações foram classificadas em quatro categorias, conforme a redução no parasitismo: inócuo (<30%); levemente nocivo (30-79%); moderadamente nocivo (80-99%); e nocivo (>99%). Os produtos fitossanitários afetaram diferentemente a capacidade de parasitismo de T. pretiosum. A seletividade das formulações de glyphosate foi dependente do tipo de sal. Aquelas à base de sal potássico (Zapp® Qi) e de sal de amônio (Roundup® WG) foram levemente nocivas a adultos do parasitóide. As demais à base de sal isopropilamina (Roundup®, Polaris®, Gliz® 480 CS, Glifosato Nortox®, Glifosato 480 Agripec® e Roundup® Transorb) foram moderadamente nocivas a adultos de T. pretiosum.
Side-effects of Pesticides Used in Integrated Production of Apples to Parasitoids of Trichogramma pretiosum Riley and Trichogramma atopovirilia Oatman & Platner (Hymenoptera: Trichogrammatidae)ABSTRACT -Parasitoids of genus Trichogramma represent an alternative to control tortricids in apple orchards; however, it is necessary to use selective pesticides for managing this crop. The side-effects of pesticides used in Integrated Production of Apples, were evaluated to parasitoid Trichogramma pretiosum Riley and Trichogramma atopovirilia Oatman & Platner (Hymenoptera: Trichogrammatidae) under laboratory conditions, by following protocols of IOBC/WPRS. Bioassays were carried with: a) adults by exposing to fresh pesticides residues, applied on glass plates; b) immature stages, with applications of pesticides on eggs of Anagasta kuehniella (Zeller) (Lepidoptera: Pyralidae), with the parasitoid in the egg-larvae, pre-pupae and pupae stages. The reduction in the parasitization (adults) and reduction on adults emergence (immatures), in relation the control were used to classified the pesticides in harmless (<30%), slightly harmful (30-79%), moderately harmful (80-99%) and harmful (>99%).Out of 60 pesticides tested in bioassays with adults of T. pretiosum, 60% were harmless, 10% slightly harmful, 16.67% moderately harmful and 13.33% harmful. In bioassays with immatures, out of 19 pesticides evaluated, 73.68% were harmless for all immatures stages and the others were slightly harmful in at least one stage. For T. atopovirilia, of the 40 pesticides evaluated with adults, 45% were harmless, 15% slightly harmful, 12.5% moderately harmful and 27.5% harmful; in bioassays with immatures of the 17 pesticides tested 58.82% were harmless for the three stages, while 41.18% were slightly harmful, moderately harmful and harmful. T. atopovirilia was more sensitive than T. pretiosum to evaluated pesticides in the tests with either adults or immatures.
Resumo -O objetivo deste trabalho foi avaliar o efeito da temperatura sobre a biologia dos biótipos "milho" e "arroz" de Spodoptera frugiperda (J.E. Smith, 1797) (Lepidoptera: Noctuidae) e estimar o número de gerações por ano em laboratório e campo. Foram coletadas lagartas de quatro populações de S. frugiperda no Estado do Rio Grande do Sul, identificadas eletroforeticamente como os biótipos "milho" e "arroz", em áreas isoladas, distanciadas entre si em mais de 300 km, produtoras de milho e arroz irrigado e em áreas adjacentes, que produzem milho e arroz irrigado lado a lado. A temperatura mais adequada para o desenvolvimento dos dois biótipos foi 25ºC. Em laboratório, podem ser obtidas 11,0 e 11,3 gerações ano -1 do biótipo "milho" proveniente de áreas isoladas e adjacentes, respectivamente. Foram estimadas 12,1 gerações ano -1 do biótipo "arroz" quando proveniente de áreas isoladas e 12,2 gerações ano -1 quando proveniente de áreas adjacentes. Em campo, estimou-se a ocorrência de 8,3 e 6,1 gerações ano -1 do biótipo "milho", respectivamente, em áreas isoladas e áreas adjacentes e 8,4 e 7,0 gerações ano -1 do biótipo "arroz", respectivamente, em áreas isoladas e áreas adjacentes. Em áreas adjacentes, o biótipo "arroz" apresenta uma geração a mais ao longo de um ano em relação ao biótipo "milho".Termos para indexação: Insecta, lagarta-do-cartucho, lagarta-da-folha, biologia, biótipos. Thermal requirements and estimate of the number of generations of biotypes "corn" and "rice" of Spodoptera frugiperdaAbstract -The objective of this work was to evaluate the effect of the temperature on the biology of the biotypes "corn" and "rice" of Spodoptera frugiperda (J.E. Smith, 1797) (Lepidoptera: Noctuidae) and to estimate the number of generations per year in laboratory and field. Caterpillars of four populations of S. frugiperda were collected in Rio Grande do Sul State, Brazil, identified by electrophoresis as the biotypes "corn" and "rice" in isolated areas (spaced for more than 300 km), areas of corn and irrigated rice production, as well as in adjacent areas that produces corn and rice irrigated side by side. The most appropriate temperature for the development of the two biotypes was 25ºC. In laboratory, a number between 11.0 and 11.3 generations year -1 for the biotype "corn" can be obtained, originating from isolated and adjacent areas, respectively, and, for the biotype "rice", 12.1 and 12.2 generations year -1 when originating from isolated and adjacent areas, respectively. In the field, the occurrence of 8.3 and 6.1 generations year -1 for the biotype "corn" was estimated, respectively, in isolated and adjacent areas and 8.4 and 7.0 generations year -1 for the "rice" biotype, respectively, in isolated and adjacent areas. In adjacent areas, the "rice" biotype presents an extra generation per year in relation to the "corn" biotype.
Effects of the maximum field recommended concentration of five pesticides currently used on peaches in Brazil; abamectin, deltamethrin, methoxyfenozide, phosmet and trichlorfon were tested on the predator Chrysoperla carnea (Stephens) (Neuroptera, Chrysopidae). Dimethoate was used as positive standard. Three analytical laboratory tests, based on IOBC-working group pesticides and beneficial organisms guidelines were used: (1) exposure to fresh pesticide residue on glass plates of (a) larvae (susceptible life stage) and (b) adults (less susceptible life stage); (2) direct spraying of eggs and pupae; (3) exposure of larvae and adults to pesticide residues on plant leaves at different intervals after application (persistence). In tests 1, abamectin was slightly harmful to C. carnea larvae and phosmet and trichlorfon were slightly harmful and moderately harmful to C. carnea adults, respectively. After direct spraying of eggs and pupae, all the pesticides were harmless. In the persistence tests, abamectin and trichlorfon were classified as short lived and therefore they could be considered for use in Integrated Pest Management (IPM) programs under special conditions (i.e. reduced direct contact). Phosmet, however, caused between 56.3 and 75.0% mortality up to 30 days after treatment and it was rated as persistent. No sublethal effects were detected in the reproductive behaviour of adults (fecundity and fertility) compared with the control in any treatment. In conclusion, the insecticides with little or no toxicity to C. carnea such as abamectin, deltamethrin and methoxyfenozide could be considered as IPM-compatible, subject to further field studies.
-The objective of this work was to analyze the biology of Spodoptera frugiperda (J.E. Smith) populations in corn and irrigated rice leaves. Caterpillars from four populations from Rio Grande do Sul state were collected from isolated areas (distant more than 300 km apart), from the counties of Santa Rosa (M/SR) and Uruguaiana (A/U), traditional areas of corn and irrigated rice production, respectively, and in adjacent areas in Pelotas county, where corn (M/P) and rice (A/P) are grown side by side. In the laboratory, 150 caterpillars were individualized in glass vials containing leaves of the Pioneer 30F33 corn hybrid and the cultivar of the irrigated rice Pelota, under controlled temperature (25 ± 1ºC), relative humidity (70 ± 10%) and photophase (14h). After adult emergence, 20 couples were individualized in cylindrical PVC cages, covered inside with paper towels, and fed with a 10% honey aqueous solution. All populations of S. frugiperda collected from corn and rice, regardless their place of origin, showed unique physiological needs, as evidenced by the different biological parameters evaluated. The Populations M/SR and M/P (maize) and A/U and A/P (irrigated rice), did not differ physiologically. Based on the results, both "corn" and "rice" S. frugiperda biotypes are present in Rio Grande do Sul.KEY WORDS: Insecta, fall armyworm, host plant, biotype RESUMO -O objetivo do trabalho foi estudar a biologia de populações de Spodoptera frugiperda (J.E. Smith) em folhas de milho e arroz irrigado. Foram coletadas lagartas de quatro populações no Rio Grande do Sul: em áreas isoladas (distanciadas em mais de 300 km), municípios de Santa Rosa (M/SR) e Uruguaiana (A/U), tradicionalmente produtores de milho e arroz irrigado, respectivamente; e, em áreas adjacentes, município de Pelotas, que produz milho (M/P) e arroz irrigado (A/P) lado a lado. Individualizaram-se 150 lagartas em tubos de vidro contendo folhas do híbrido de milho Pioneer 30F33 e do cultivar de arroz irrigado Pelota, em condições controladas de temperatura (25 ± 1ºC), umidade relativa (70 ± 10%) e fotofase (14h). Por ocasião da emergência dos adultos, 20 casais foram individualizados em gaiolas cilíndricas de PVC revestidas internamente com papel jornal, e alimentados com solução aquosa de mel a 10%. As populações de S. frugiperda originárias do milho e arroz, independente do local de coleta, apresentaram necessidades fisiológicas intrínsecas e que são evidenciadas nos diferentes parâmetros biológicos avaliados. As populações M/SR e M/P (cultura do milho) e A/U e A/P (cultura do arroz irrigado), não apresentaram diferenças fisiológicas. Diante dos resultados, conclui-se que ambos biótipos "milho" e "arroz" de S. frugiperda ocorrem no Rio Grande do Sul. PALAVRAS-CHAVE: Insecta, lagarta-do-cartucho, lagarta-da-folha, planta hospedeira, biótipoAs culturas do milho e do arroz irrigado apresentam significativa importância sócio-econômica para o Rio Grande do Sul. Porém, o ataque de pragas desfolhadoras tem causado significativa redução na sua produtivid...
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