Avaliação de inseticidas no controle de Sitophilus oryzae (Linnaeus) (Coleoptera, Curculionidae) e Rhyzopertha dominica (Fabricius) (Coleoptera, Bostrichidae) em trigo armazenado

Abstract

ABSTRACT. Efficacy of insecticides to control Sitopllilus oryzae (Linnaeus) (Coleoptera, Curcul ionidae) a nd Rltyzoperflla domillica (Fabrici us) (Coleoptera, Bostrichidae) in stored wheat. The efficiency of insecticides against Sitophilus o/yzae (Linnaeus, 1763) (Coleoptera, Curculionidae) and Rhyzoperlha dominica (Fabricius, 1792) (Coleoptera, Bostrichidae) was detennined exposing them to treated wheat in laboratory. Each plot, which was composed by 1.2 kg of wheat grain, was treated with 5 mi of the concentration/kg of wheat using a propelling air atomizeI'. Fifteen days after lreatment 50 g samples of the grain were tak en, trom each plot, placed in plastic jars into which 10 adult insects of each species were released. This was repeated every 30 days until 165 days after treatment. The number of dead insects was counled 15 days after each infestation thus the evaluations were made at 30, 60, 90, 120, 150 and 180 days after the insecticide application. Esfenvalerate+fenitrothi-on+pyperonil butoxide (0,375+ 7,5+ 3,0 and 0,5+ 10,0+4,0 g a.i./t), fenitrothion+esfen-valera te (7,5+0,375 and 10,0+0,375 g a.i./t), fenitrothion+synergised deltamethrin (7,5+0,375 g a. i.!t) and fenitrothion (7,5 g a.i .!t) were effective against Silophilus oryzae until 180 days after treatment. Esfenvalerate+fenitrothion+pyperonil butoxide (0,5+ I 0,0+4,0 g a.i .!t), fenitrothion+esfenvalerate (7,5+0,375 and 10,0+0,375 g a.i./t), fenitrothion+synergised deltamethrin (7,5+0,375 g a.i.!t) were effective against R. dominica until 180 days after trealment. Synergised deltamethrin (0,375 g a.i./t) was effective against S. o/yzae until 150 days and against R. dominica until 120 days after lreatment. Estenvalerate (0,5 g a.i .!t) was ineffective against S. o/yzae and eftective until 60 days after treatmenl against R. dominica. Fenitrothion (7,5 g a.i./t) was ineffective against R. domillica. The use of mixtures of organophosphorus plus pyrethroids were more effective against S. o/yzae and R. dominica when compared with these insecticides used alone. KEY WORDS. lnsecta, chemical control, stored-product pests A cultura do trigo, no Brasil e a nível mundial , sempre mereceu destaque, tratando-se do mais importante cereal cultivado pelo homem, principalmente, devido à sua ampla utili zação na alimentação humana (SCHEEREN 1986).

Impact of resistance to fenitrothion and esfenvalerate on the control of Rhyzopertha dominica (Coleoptera: Bostrichidae) in stored wheat

“…In the 90's, fenitrothion and esfenvalerate insecticides were effective in the control of R. dominica in Brazil (Furiatti et al 1999), the continuous use of these insecticides without an adequate rotation program has led to the failure of these tools to control the lesser grain borer. On the other hand, cross-resistance between pyrethroids has been demonstrated in populations of R. dominica from Brazil (Lorini and Galley 2001).…”

Eficiência de inseticidas no controle de Sitophilus oryzae (L.) (COLEOPTERA: CURCULIONIDAE) e Rhyzopertha dominica (FAB.) (COLEOPTERA: BOSTRICHIDAE) em cevada armazenada

“…Para o fenitrothion os resultados obtidos no controle de S. oryzae são concordantes com os obtidos por Pereira et al (1997) e Furiatti et al (1999) quando foi observada eficiência deste ingrediente ativo até 180 dias após a aplicação em grãos de milho e trigo, respectivamente. No entanto, em arroz Apêndice 1.…”

“…Para a deltametrina + BPO os resultados obtidos no controle de S. oryzae são concordantes com os observados por Bitran et al (1991), Pereira et al (1997) e Pinto Jr. et al (1997 que testando inseticidas na proteção de milho, trigo e arroz em casca, observaram um decréscimo na ação residual deste ingrediente ativo. Furiatti et al (1999), entretanto, observaram a sua eficiência com S. oryzae até 150 dias após a aplicação. Os resultados obtidos no controle de R. dominica estão discordantes com os obtidos por Pereira et al (1997), Pinto Jr. et al (1997) e Furiatti et al (1999 que observaram a eficiência de deltametrina + BPO até os 120 dias após a aplicação em grãos de milho, arroz em casca e trigo, respectivamente.…”

Walking stability of Rhyzopertha dominica (Fabricius, 1792) (Coleoptera: Bostrichidae)

“…Both species, R. dominica and T. castaneum are the reasons for studies seeking to evaluate responses to the use of insecticides (Aguiar et al, 2010;Furiatti et al, 1999;Pereira et al, 1997Pereira et al, , 2003Pimentel et al, 2012;Pinto Junior et al, 1997;Santos et al, 2011), control measures (Gonçalves et al, 2000(Gonçalves et al, , 2007Mariano et al, 2006), forms of repellency (Beckel et al, 2004(Beckel et al, , 2005Parvin et al, 2012) and damage caused (Alencar et al, 2011;Silva et al, 2003). In general, these studies present the common fact that they are conducted under simulated conditions in the laboratory, testing the species in the different situations observed in the storage units.…”