Toxicities and effects of insecticidal toxic baits to control Drosophila suzukii and Zaprionus indianus (Diptera: Drosophilidae).

BACKGROUND: Drosophila suzukii is a primary insect pest that causes direct damage to fruits with a thin epidermis such as strawberries, cherries and blueberries. In strawberry fields, the co-occurrence of D. suzukii and Zaprionus indianus has increased production losses. This study evaluated the toxicities and effects of insecticidal baits to control adults and larvae of both D. suzukii and Z. indianus . RESULTS: Organophosphate (dimethoate and malathion), spinosyn (spinosad and spinetoram), pyrethroid (lambda-cyhalothrin) and diamide (cyantraniliprole) insecticides exhibited high toxicity to both adults and larvae of D. suzukii and Z. indianus (mortality > 80%) in topical and dip bioassays. However, when the insecticides were mixed with a feeding attractant, a positive effect was observed only for adults of D. suzukii . Insecticides containing neonicotinoids (acetamiprid and thiamethoxam) and pyrolle (chlorfenapyr) caused intermediate mortality to adults of D. suzukii (40?60%) and low mortality for Z. indianus (mortality < 23%); however, these compounds reduced the larval infestation of the two species by 55?86%. Botanical (azadirachtin) and sulphur insecticides exhibited low toxicity (mortality < 40%) on adults and larvae of both species. CONCLUSION: Dimethoate, malathion, spinosad, spinetoram, lambda-cyhalothrin and cyantraniliprole are highly toxic to both larvaeandadultsof D. suzukii and Z.indianus .Theuseoftoxicbaitsforadultsof D. suzukii couldbeanalternativeinmanagement of this species. © 2016 Society of Chemical Industry Keywords: spotted-wing drosophila; fig fly; chemical control; strawberry; toxic bait; pest control.

Suscetibilidade de populações de Chrysodexis includens e Helicoverpa armigera a inseticidas do grupo das diamidas.

2016

Controle de Helicoverpa armigera (Lepidoptera: Noctuidae) em soja com inseticidas químicos e biológicos.

RESUMO: O objetivo deste trabalho foi avaliar o desempenho de inseticidas autorizados emergencialmente para o controle de Helicoverpa armigera (Lepidoptera: Noctuidae) em soja. Sete inseticidas foram pulverizados em campo e, após 24 horas, folhas do ponteiro foram coletadas e oferecidas para lagartas de 2o instar em laboratório. Lagartas do 4o instar receberam a última folha trifoliolada que se encontrava completamente expandida no momento da pulverização. Outro grupo foi exposto a folhas coletadas a partir de 72 horas da pulverização. Em campo, seis inseticidas foram pulverizados e, em seguida, as plantas foram infestadas com lagartas de 2o e 3o instar. No primeiro estudo, flubendiamida, clorantraniliprole, clorfenapir, indoxacarbe e metoxifenozida causaram 100% de mortalidade do 4o instar aos oito dias após o início da exposição, enquanto baculovírus e Bacillus thuringiensis (Bt) propiciaram mortalidade de 60-75%, que evoluiu para 88?90% ao final da fase de pupa. Para o 2o instar, apenas flubendiamida e clorantraniliprole proporcionaram mortalidade de 100%. Flubendiamida, clorantraniliprole e clorfenapir apresentaram o menor tempo letal para o 4o instar, e flubendiamida e clorantraniliprole, para o 2o instar. Após 72 horas da pulverização, o desempenho dos inseticidas foi insatisfatório. Em campo, houve eficiência satisfatória de flubendiamida, espinosade, baculovírus e Bt sobre lagartas de 2o e 3o instar. ABSTRACT:The objective of this work was to evaluate the performance of insecticides authorized on an emergency basis to control of Helicoverpa armigera (Lepidoptera: Noctuidae) in soybean. Seven insecticides were sprayed on the field and, 24 hours after that, soybean pointer leaves were collected and offered to 2nd instar larvae in the laboratory. Fourth instar larvae received the last trifoliate leaf that was fully expanded at the time of spraying. Another larvae group was exposed to leaves collected from 72 hours onwards after spraying. In the field, six insecticides were sprayed, and then the plants were infested with 2nd and 3rd instar larvae. In the first study, flubendiamide, chlorantraniliprole, chlorfenapyr, indoxacarb, and methoxyfenozide caused 100% mortality of the 4th instar, eight days after the beginning of exposure, while baculovirus and Bacillus thuringiensis (Bt) caused 60?75% mortality, which reached 88?90% at the end of the pupal stage. For 2nd instar larvae, only flubendiamide and chlorantraniliprole caused 100% mortality. Flubendiamide, chlorantraniliprole, and chlorfenapyr showed the lowest lethal time for the 4th instar, and flubendiamide and chlorantraniliprole for the 2nd instar. Seventy-two hours after spraying, the performance of insecticides was not satisfactory. In the field, there was satisfactory efficiency of flubendiamide, spinosad, baculovirus, and Bt on 2nd and 3rd instar larvae.

Grape phylloxera in Brazil.

There are approximately 90,000 ha of grapes in Brazil including wine, juice and table grapes. American varieties (Isabella, Niagara, Ives) comprise the largest part of Brazilian viticulture being destined for wine, juice and table grape. In Southern Brazil, these varieties are produced mainly in non grafted vineyards. Grape phylloxera is common on the roots of these varieties however the insect is not regarded as a serious problem. Leaf galls are common on V. vinifera cultivars, particularly Cabernet sauvignon, and this infestation can be severe in some years causing defoliation. No information about insect damage on leaves in relation to vineyard production and longevity is available. New selections from a breeding program aimed at developing new hybrids for wine production are highly susceptible to damage from leaf galling phylloxera. When leaf galling is severe, growers spray pyretroid and neonicotinoid insecticides however, in many situations, secondary mites can also damage the crop as a consequence of the foliar broad spectrum insecticides application. Studies about the genetic diversity of grape phylloxera strains in Brazil and their association with vine damage and secondary fungal infection must be conducted to clarify the importance of this pest to Brazilian viticulture.

Toxicities and effects of insecticidal toxic baits to control Drosophila suzukii and Zaprionus indianus (Diptera: Drosophilidae).

BACKGROUND: Drosophila suzukii is a primary insect pest that causes direct damage to fruits with a thin epidermis such as strawberries, cherries and blueberries. In strawberry fields, the co-occurrence of D. suzukii and Zaprionus indianus has increased production losses. This study evaluated the toxicities and effects of insecticidal baits to control adults and larvae of both D. suzukii and Z. indianus . RESULTS: Organophosphate (dimethoate and malathion), spinosyn (spinosad and spinetoram), pyrethroid (lambda-cyhalothrin) and diamide (cyantraniliprole) insecticides exhibited high toxicity to both adults and larvae of D. suzukii and Z. indianus (mortality > 80%) in topical and dip bioassays. However, when the insecticides were mixed with a feeding attractant, a positive effect was observed only for adults of D. suzukii . Insecticides containing neonicotinoids (acetamiprid and thiamethoxam) and pyrolle (chlorfenapyr) caused intermediate mortality to adults of D. suzukii (40?60%) and low mortality for Z. indianus (mortality < 23%); however, these compounds reduced the larval infestation of the two species by 55?86%. Botanical (azadirachtin) and sulphur insecticides exhibited low toxicity (mortality < 40%) on adults and larvae of both species. CONCLUSION: Dimethoate, malathion, spinosad, spinetoram, lambda-cyhalothrin and cyantraniliprole are highly toxic to both larvaeandadultsof D. suzukii and Z.indianus .Theuseoftoxicbaitsforadultsof D. suzukii couldbeanalternativeinmanagement of this species. © 2016 Society of Chemical Industry Keywords: spotted-wing drosophila; fig fly; chemical control; strawberry; toxic bait; pest control.

Controle de pragas iniciais de sorgo sacarino com inseticidas químicos.

2016

Residual effects of pesticides in peach orchards on the maize weevil Sitophilus zeamais (Coleoptera: Curculionidae)¹.

2016

Prediction of a low-risk concentration of diflubenzuron to aquatic organisms and evaluation of clay and gravel in reducing the toxicity.

Resumo: Predição da concentração de baixo risco de diflubenzuron para organismos aquáticos e avaliação da argila e brita na redução da toxicidade. O diflubenzuron é um inseticida que além de ser usado agricultura, tem sido amplamente empregado na piscicultura, apesar do seu uso ser proibido nesta atividade. Este composto não consta na lista da legislação brasileira que estabelece limites máximos permissíveis em corpos de água para a proteção das comunidades aquáticas. No presente trabalho, a partir da toxicidade do diflubenzuron em organismos não-alvo, foi calculada a concentração de risco para somente 5% das espécies (HC5). O valor deste parâmetro foi estimado em aproximadamente 7 x 10-6 mg L-1 . Este baixo valor é devido à extremamente alta toxicidade do diflubenzuron para dafnídeos e à grande variação de sensibilidade entre as espécies testadas. Dois matérias de relativamente baixo custo se mostraram eficientes na remoção da toxicidade do diflubenzuron de soluções contendo este composto. Dentre esses materiais, a argila expandida promoveu a redução em aproximadamente 50% da toxicidade de uma solução contendo diflubenzuron. Os resultados podem contribuir para políticas públicas no Brasil relacionadas ao estabelecimento de limites máximos permissíveis de xenobióticos no compartimento aquático. Também, para a pesquisa de matérias inertes e de baixo custo com potencial de remoção de xenobióticos presentes em efluentes da aquicultura ou da agricultura. Abstract: Diflubenzuron is an insecticide that, besides being used in the agriculture, has been widely used in fish farming. However, its use is prohibited in this activity. Diflubenzuron is not in the list of Brazilian legislation establishing maximum permissible limits in water bodies for the protection of aquatic communities. In this paper, according toxicity data of diflubenzuron in non-target organisms, it was calculated an hazardous concentration for only 5% of the species (HC5) of the aquatic community. This parameter value was estimated to be about 7 x 10 -6 mg L -1 . The low value is due to the extreme high toxicity of diflubenzuron to daphnids and to the large variation in sensitivity among the species tested. Two relatively low cost and inert materials were efficient in removing the diflubenzuron from solutions containing this compound. Among these materials, expanded clay shown to promote reduction of approximately 50% of the toxicity of a solution containing diflubenzuron. The results may contribute to the establishment of public policies in Brazil associated to the definition of maximum permissible limits of xenobiotics in the aquatic compartment. This study is also relevant to the search of low cost and inert materials for xenobiotics removal from aquaculture or agricultural effluents.