The cross-resistance spectrum in deltamethrin resistance strains of Rhyzopertha dominica (F.) (Coleoptera: Bostrychidae)

Abstract

Resistência Cruzada em Raças de Rhyzopertha dominica (F.) (Coleoptera; Bostrychidae)Resistentes ao Inseticida Deltametrina RESUMO -Objetivou-se verificar a existência de resistência cruzada em raças de Rhyzopertha dominica (F.) resistentes ao inseticida deltametrina. Os experimentos foram conduzidos testando outros três inseticidas, também usados para controlar pragas de grãos armazenados, como permetrina (piretróide), pirimifós-metil e clorpirifós-metil (organofosforados). Quatro raças da praga foram usadas: duas raças suscetíveis, BR4 e UK1, e duas raças resistentes, BR6 e BR7, todas mantidas em laboratório após a coleta nos armazéns. Inicialmente todas as raças foram avaliadas em sua susceptibilidade ao inseticida deltametrina. Posteriormente, cada raça foi submetida a pressão de seleção ao inseticida deltametrina por três gerações consecutivas e no final da terceira geração cada raça foi avaliada em sua suscetibilidade com todos os inseticidas para determinar a resistência cruzada. Os resultados mostraram a existência de resistência cruzada para o inseticida permetrina, nas raças BR6 e BR7 de R. dominica. Não houve resistência cruzada aos dois inseticidas organofosforados testados. Isso indica que a resistência cruzada ocorreu dentro do mesmo grupo químico de inseticidas e não entre diferentes grupos.PALAVRAS-CHAVE: Insecta, pragas de grãos armazenados, permetrina, pirimifós-metil, clorpirifós-metil.ABSTRACT -In order to verify if there was cross-resistance in deltamethrin resistance strains of Rhyzopertha dominica (F.), experiments were carried out with three insecticides used in stored grain to control pests: permethrin (pyrethroid), pirimiphos-methyl and chlorpyrifos-methyl (organophosphates). Three strains from Brazil (BR4, BR6 and BR7) and one from United Kingdom (UK1) were tested. The strains BR4 and UK1 were susceptible and BR6 and BR7 were resistant to deltamethrin. Initially all strains were assessed in their susceptibility to deltamethrin insecticide. Then, after they were submitted to deltamethrin selection pressure throughout three generations, each strain was assessed with all other insecticides to determine the cross-resistance spectrum. Results showed that cross-resistance to permethrin existed in the BR6 and BR7 strains of R. dominica. No crossresistance to the organophosphates, pirimiphos-methyl and chlorpyrifos-methyl, was detected in deltamethrin-resistant strains.KEY WORDS: Insecta, stored grain pest, permethrin, pirimiphos-methyl, chlorpyrifos-methyl.The cross-resistance spectrum exhibited by a species is a very useful tool in detecting the mechanism involved in resistance of a pest to a specific pesticide (Scott 1990). The patterns of cross-resistance of the house fly Musca domestica L. showed that resistance to organophosphorus insecticides conferred resistance to carbamate but not to pyrethroids (Kudamatsu et al. 1983). This pattern was similar to one found by Champ and Campbell-Brown (Champ & Campbell-Brown 1970b), where malathion resistant strains of Tribolium castaneum (Herbst) we...

Eficácia de inseticidas alternativos e biológicos sobre Sitophilus zeamais (Coleoptera: Curculionidae) em grãos de milho

“…O tratamento químico contendo Bacillariophyta (terra da diatomácea) apresentou elevada mortalidade (84,21%) para o gorgulho do milho no sexto dia de avaliação, diferindo-se estatisticamente dos demais tratamentos (Tabela 2). Essa expressiva mortalidade dos insetos está atrelada a eficiência da terra de diatomácea, uma vez que esse produto possui sílica em sua composição (Lorini & Galley, 2001).…”

Identification of fungi in Tunisian olive orchards: characterization and biological control potential

“…The inhibition zones diameterincrease concurrently. + [5][6][7][8][9][10], ++ [11][12][13][14][15][16][17][18][19][20], +++ [21][22][23][24][25][26][27][28][29][30][31][32][33][34][35][36][37][38][39][40], − no zones of inhibition Fig. 2 Mean mortality rate of forth instar Ephestia kuehniella larvae fed with semolina mixed with conidial suspension of fungi at concentration adjusted to 10 7 conidia/ml, 7 days after treatment.…”

“…The control of these pests and pathogens has been based on the application of chemical pesticides - e.g. those based on synthetic pyrethroids - characterized by their damaging effects to the ecosystems [ 16 ] as, e.g., pest-resistance problems [ 17 ], side-effects on auxiliary fauna [ 18 , 19 ] and human health [ 20 ]. However, these practices are being replaced by biological control methods.…”

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). It is likely that the intensive use of other pyrethroids has favored resistance to esfenvalerate.…”