Control of linepithema micans (hymenoptera: formicidae) and eurhizococcus brasiliensis (hemiptera: margarodidae) in vineyards using toxic baits.

Linepithema micans (Forel) (Hymenoptera: Formicidae) is the main ant species responsible for dispersal of Eurhizococcus brasiliensis (Wille) (Hemiptera: Margarodidae), a root scale that damages grapevines in southern Brazil. The effects of different formulations of toxic baits based on boric acid and hydramethylnon to control L. micans and E. brasiliensis were evaluated. Toxic baits with boric acid (1.0%) mixed in different concentrations of inverted sugar (20%, 30%, and 40%), and hydramethylnon, mixed with sardines (paste), cassava flour and peanut, brown sugar (sucrose), or sardine oil-based gel, were evaluated in a greenhouse and in the field. In the greenhouse experiment, the number of foraging ants was significantly reduced in the pots where the hydrame- thylnon in sardine paste (Solid S), sardine oil-brown sugar-based gel (GEL SAM), and peanut oil-brown-sugar gel (GEL AM) formulations were applied. The GEL SAM toxic bait effectively reduced the infestation of L. micans , and could be used for indirect control of E. brasiliensis on young grapevines. Keywords : hydramethylnon, ant, scale, contro

Quando controlar os percevejos na soja?

O uso de inseticidas é justificável quando a população de percevejos for igual ou superior a dois por metro (nível de ação = NA). Entretanto, a confiabilidade desse NA tem sido questionada nos últimos anos e por isto, este trabalho objetivou avaliar em campo, o NA em duas safras de soja. Os experimentos foram conduzidos com as cultivares ?BMX Potência RR? (GM 6.7; crescimento indeterminado) e ?BRS 294 RR? (GM 6.3; crescimento determinado). A produtividade diferiu apenas entre os diferentes tratamentos em relação à testemunha (sem controle) na safra 10/11. Na safra 11/12 mesmo a infestação ultrapassando o NA na testemunha no estádio R5.4 e se mantendo acima desse nível até a colheita, a produtividade não diferiu do tratamento com maior controle de percevejos (1/4 NA). Quanto à qualidade da soja, na safra 10/11 apenas a testemunha apresentou diferença entre os tratamentos com 13,7% de sementes não viáveis pelo dano de percevejos (teste de tetrazólio 6-8). Em 11/12, os resultados foram semelhantes. Os tratamentos ¼NA e NA não diferiram entre si com 2,44 e 4,25% dos grãos com sementes não viáveis, respectivamente. Em ambos os anos, os tratamentos NA; ¼NA e aplicação de inseticidas com herbicidas e fungicidas independente do nível de percevejos, apresentaram sementes não viáveis inferiores a 6%, intensidade de dano aceita para lavouras de produção de sementes, cujos padrões são mais exigentes em relação à produção de grãos. Portanto, o controle de percevejos associado ao uso de herbicidas e fungicidas ou adotando ¼ do NA de percevejos é inviável, principalmente por não apresentar benefícios na produtividade ou na qualidade da produção obtida e, ainda, aumentar de 1 a 4 aplicações. O tratamento que aguardou o NA recomendado para percevejos, além da redução do risco ambiental, apresentou maior economia de inseticidas. Portanto, a aplicação no momento correto (dois percevejos m-1) é considerado o tratamento mais sustentável entre os diferentes manejos avaliados

Lepidopteran larva consumption of soybean foliage: basis for developing multiple-species economic thresholds for pest management decisions.

BACKGROUND: Defoliation by Anticarsia gemmatalis (H ¨ ubner), Pseudoplusia includens (Walker), Spodoptera eridania (Cramer), S. cosmioides (Walker) and S. frugiperda (JE Smith) (Lepidoptera: Noctuidae) was evaluated in four soybean genotypes. A multiple-species economic threshold (ET), based upon the species? feeding capacity, is proposed with the aim of improving growers? management decisions on when to initiate control measures for the species complex. RESULTS: Consumption by A. gemmatalis, S. cosmioides or S. eridania on different genotypes was similar. The highest consumption of P. includens was 92.7 cm2 on Codetec 219RR; that of S. frugiperda was 118 cm2 on Codetec 219RR and 115.1 cm2 on MSoy 8787RR. The insect injury equivalent for S. cosmoides, calculated on the basis of insect consumption, was double the standard consumption by A. gemmatalis, and statistically different from the other species tested, which were similar to each other. CONCLUSIONS: As S. cosmioides always defoliated nearly twice the leaf area of the other species, the injury equivalent would be 2 for this lepidopteran species and 1 for the other species. The recommended multiple-species ET to trigger the beginning of insect control would then be 20 insect equivalents per linear metre

Evaluation of insecticides for the control of Linepithema Micans (Hymenoptera: Formicidae).

Linepithema micans (Forel) (Hymenoptera: Formicidae) is the main ant species responsible for the spreading of Eurhizococcus brasiliensis (Wille) (Hemiptera: Margarodidae), a soil scale that damages grapevine plants in southern Brazil. The effect of contact and ingestion of insecticides on the control of L. micans was evaluated in a greenhouse using grapevines (Vitis spp.) infested by L. micans. The insecticides thiamethoxam (250, 187.5, and 125 g/ha), Þpronil (4, 5, and 50 ml/ha), and imidacloprid (650 g/ha) were sprayed on the ground, whereas toxic baits containing boric acid (0.5, 1.0, and 1.2%), pyriproxyfen (0.3 and 0.5%), and hydramethylnon (0.5%) were evaluated in different formulations. Hydramethylnon (toxic bait) and thiamethoxam (chemical barrier) were the most efÞcient active ingredients for the control of L. micans

Seletividde de agrotóxicos aos parasitoides de ovos Trichogramma pretiosum E Telenomus remus.

Os parasitoides de ovos destacam-se por atacarem a fase de ovo das pragas, controlando-as antes de causarem danos às plantas. Entretanto, a aplicação de agrotóxicos ainda é indispensável para garantir a boa produtividade das culturas. Neste contexto, em programas de manejo integrado de pragas (MIP), é recomendável utilizar diversas táticas para reduzir os danos dos insetos-praga e, portanto, a associação do controle químico e biológico é viável com a utilização de produtos seletivos aos inimigos naturais. Assim, avaliou-se a seletividade de espiromesifeno, flubendiamida, espirotetramate + imidacloprido, clorpirifós, cletodim, clorimurom-etílico, éster metílico de óleo de soja e a mistura deste último com espirotetramate + imidacloprido sobre os adultos de Trichogramma pretiosum Riley (Hymenoptera: Trichogrammatidae) e Telenomus remus (Nixon) (Hymenoptera: Scelionidae) e pupas de T. pretiosum segundo as normas padronizadas da “International Organization for Biological Control” (IOBC) em laboratório. Entre os tratamentos testados (g. ia/ha), os inseticidas espiromesifeno (144), flubendiamida (12) e espirotetramate (30) + imidacloprido (90) foram seletivos as fases dos parasitoides avaliadas. O adjuvante éster metílico de óleo de soja (360) também foi seletivo, entretanto, quando misturado com o espirotetramate (30) + imidacloprido (90) apresentou uma redução no parasitismo 2 e 5 dias após o início dos ensaios com T. remus e T. pretiosum, respectivamente. Flubendiamida (33,6) também foi seletivo para adultos de T. remus e pupas de T. pretiosum, mas reduziu a taxa de parasitismo após o segundo dia do ensaio com adultos de T. pretiosum. Os herbicidas cletodim (108) e clorimurom-etílico (20) foram seletivos a adultos de T. remus mas tiveram maior impacto sobre T. pretiosum reduzindo o parasitismo desse agente de controle biológico que se mostrou mais sensível a esses produtos. O inseticida clorpirifós (480) foi nocivo a todas as fases dos parasitoides avaliadas. Em geral, ocorreram diferenças na seletividade dos agrotóxicos avaliados aos inimigos naturais, além de diferenças na sensibilidade dos mesmos em relação aos produtos e doses testados. Portanto, em programas de MIP devem ser priorizados os agrotóxicos seletivos ao maior número de agentes de controle biológico.SICONBIOL 2011

The use of soybean integrated pest management in Brazil: a review.

The adoption of integrated pest management (IPM) in soybean is a great example of how this technology is essential to guarantee crop sustainability and productivity. In Brazil, up to 1970, soybean was cultivated with the use of pesticides applied without the adoption of any economic threshold to base this decision. As a consequence, a six-insecticide spraying per crop season used to be the average insecticide dosage. With the introduction of Soybean-IPM, the use of pesticides was reduced to approximately two applications per season. Comparing these two contrasting situations, the advantages of using IPM methods cannot be ignored, since they are economically and mostly environmentally feasible. Despite the benefits provided by Soybean-IPM, this program was abandoned in Brazil, and its principles were almost forgotten, and, as a consequence, insecticide use increased. The success and failures of Soybean-IPM in Brazil will be further analyzed in this review in an attempt to point out how safe this technology is and whether there is any risk in fully adopting this approach

The influence of Bt-maize on biological traits of Spodoptera eridania (Cramer, 1782) and Spodoptera frugiperda (Smith, 1789) (Lepidoptera: Noctuidae).

The cultivation of genetically modified plants (e.g. Bt-maize) is currently an alternative method of controlling major crops pests. Therefore, is important to know the influence of Bt-plants on pest and non-pest insects. This study aimed evaluate the impact of Cry1F and Cry1F+Cry1A.105+Cry2Ab2 proteins Bt expressed in corncobs on larval development of Spodoptera eridania (Cramer, 1782) and Spodoptera frugiperda (Smith, 1789) (Lepidoptera: Noctuidae). The immature grains were offered ad libitum to new-hatched larvae (until 24 hs old), to compare the development of the specimens fed to non-Bt corn (DOW 2B688) and two isogenic Bt, that express one (Cry1F) and three insecticides protein (Cry1F+Cry 1A.105+Cry2Ab2). The larvae survived less than two days when consumed both Bt immature grains and reach 100% of mortality. Spodoptera eridania reared on non-Bt corns grains shows a longer longevity (21.6 days) than S. frugiperda (18.4 days), but a lower viability (56.5% and 80.2% to S. eridania and S. frugiperda, respectively). Interesting, S. eridania consume a more amount immature grains (5.4g) than S. frugiperda (3.9 g). In summary, this study confirms that the toxins Cry1F, Cry1F+Cry 1A.105+Cry2Ab2 expressed in fresh corncobs are an important tool to protect the corn ears against S. frugiperda and the nontarget pest S. eridania, however is important monitored the non-Bt corn fields due the possibility of this species caused damage in ears corn

Exact and Approximate Formulas for Neutrino Mixing and Oscillations with Non-Standard Interactions

We present, both exactly and approximately, a complete set of mappings between the vacuum (or fundamental) leptonic mixing parameters and the effective ones in matter with non-standard neutrino interaction (NSI) effects included. Within the three-flavor neutrino framework and a constant matter density profile, a full set of sum rules is established, which enables us to reconstruct the moduli of the effective leptonic mixing matrix elements, in terms of the vacuum mixing parameters in order to reproduce the neutrino oscillation probabilities for future long-baseline experiments. Very compact, but quite accurate, approximate mappings are obtained based on series expansions in the neutrino mass hierarchy parameter \eta \equiv \Delta m^2_{21}/\Delta m^2_{31}, the vacuum leptonic mixing parameter s_{13} \equiv \sin\theta_{13}, and the NSI parameters \epsilon_{\alpha\beta}. A detailed numerical analysis about how the NSIs affect the smallest leptonic mixing angle \theta_{13}, the deviation of the leptonic mixing angle \theta_{23} from its maximal mixing value, and the transition probabilities useful for future experiments are performed using our analytical results.Comment: 29 pages, 8 figures, final version published in J. High Energy Phy