Ação residual de agrotóxicos pulverizados em plantas de milho sobre Trichogramma pretiosum

Abstract

Submetido em 16/12/2014 Objetivou-se, com este trabalho, avaliar a ação residual de nove inseticidas e de um fungicida-acaricida sobre o parasitoide Trichogramma pretiosum (Riley, 1879), em condições de semicampo, sob telado. Plantas de milho foram pulverizadas com os agrotóxicos até o ponto de escorrimento, três dias antes da montagem dos ensaios. Ovos de Anagasta kuehniella (Zeller, 1879) foram ofertados, em cartelas de cartolina azul, individualizadas no interior de gaiolas. Os adultos recém-emergidos de T. pretiosum foram liberados na proporção de 1,6 fêmeas por ovo do hospedeiro alternativo. As liberações de T. pretiosum foram realizadas aos 3, 10, 17, 24 e 31 dias após a pulverização das plantas. Os agrotóxicos foram classificados quanto a sua persistência, seguindo-se a escala proposta pela IOBC. Os resultados mostraram que os produtos comerciais-ingredientes ativos (kg ou L ha -1 ) usados na cultura do milho, beta-ciflutrina (0,10), cipermetrina (0,08), clorpirifós (1,00), lambda-cialotrina 50 (0,15), enxofre (1,00), metomil (0,60) e tiodicarbe (0,15) foram moderadamente persistentes (classe 3) (16-30 dias de ação nociva) e lambda-cialotrina 250 (0,10), espinosade (0,10) e lambda-cialotrina + tiametoxam (0,25), foram persistentes (classe 4) (> 31 dias de ação nociva sobre T. pretiosum). Palavras Residual action of pesticides sprayed on corn plants on Trichogramma pretiosumThe objective of this study was to evaluate the residual effect of nine pesticides and a fungicide/acaricide on the parasitoid Trichogramma pretiosum Riley, 1879, in field conditions. Corn plants were sprayed with pesticides up to the runoff point three days before assembling the bioassays. Anagasta kuehniella (Zeller, 1879) eggs were offered in blue cardstock cards, individualized within the cages. The newly emerged adults of T. pretiosum were released in the proportion of 1.6 female per egg of the alternative host. Releases of the parasitoids were performed at 3, 10, 17, 24, and 31 days after spraying the plants. The pesticides were classified by their persistence, following the scale proposed by IOBC. The results showed that the commercial/active ingredients (kg or L ha.-1 ), used in corn, beta-cyfluthrin (0.10), cypermethrin (0.08), chlorpyrifos (1.00), lambda-cyhalothrin 50 (0.15), methomyl (0.60), sulfur (1.00), and thiodicarb (0.15) were moderately persistent (class 3; 6-30 days of harmful action) and lambda-cyhalothrin 250 (0.10), lambdacyhalothrin + thiamethoxam (0.25), and spinosad (0.10) were persistent (Class 4; > 31 days of harmful action) on T. pretiosum.

50 Management of Coffee Leaf Miner: Spray Volume, Efficacy of Cartap Hydrochloride and Impact on Parasitism

“…Most of the studies available in the literature on the selectivity of insecticides to the natural enemies of the coffee tree, approach the selectivity in favor of predators, such as the predatory wasps of leaf miner (GUSMÃO et al, 2000;FRAGOSO et al, 2001), chrysopides (VILELA et al, 2010) and lady bug (ROCHA et al, 2010;. In other cultures, studies have shown that cartap may reduce parasitism (PASINI et al, 2017) and affect the sex ratio (CARVALHO et al, 2003) of Trichogramma pretiosum Riley in tomato.…”

Biological Pest Control in Maize Crop in Brazil: A Review

“…The female individual of this parasitoid lays her eggs inside the egg of the plague and the end of the biological cycle emerges the adult (Cruz, 2015). The great differential in favor of the exclusive biological control agents of eggs, consists in the reduction of the population of the pest, preventing injury to the plant, being efficient in the pest control Spodoptera frugiperda, Helicoverpa zea, Helicoverpa armigera (Pasini et al, 2017), Diatraea saccharalis (Santos & Cruz, 2017), Elasmopalpus lignosellus (Xavier et al, 2011). In the parasitism of the eggs of Agrotis ípsilon, Trichogramma Pretisoum and Trichogramma Atopovirilia stand out demonstrating high potential for use in pest management (Kaiser, 2016).…”

Selectivity of insecticides with two active ingredients on the parasitoid >i<Trichogramma pretiosum>/i< (Hymenoptera: Trichogrammatidae)

“…The ready-mix pesticides tested in this study, caused some harmful effects on our subject parasitoid, T. pretiosum, at 15 DAS. Pasini et al (2017) studied the persistence of cypermethrin (0.008% a.i. ), lambda-cyhalothrin (0.003%) and methomyl (0.064%), in single formulations, on T.…”

“…pretiosum, and classified all these active ingredients as class 3, reducing the parasitism for more than 24 days; whereas in our study, the same insecticides were classified as short-lived. The exposure route might account for this difference, since Pasini et al (2017) released the parasitoids in cages inside a greenhouse. The difference might also stem from the formulations used, since in the present study these active ingredients were tested in ready-mixes and in lower concentrations.…”