Susceptibilidade de adultos de Trichogramma pretiosum Riley (Hymenoptera: Trichogrammatidae) a fungicidas utilizados no controle de doenças da macieira

Abstract

-This study evaluated the susceptibility under laboratory conditions of Trichogramma pretiosum Riley adults to fungicides recommended by the Integrated Production of Apple (IPA). The bioassays were carried out using the International Organization for Biological Control (IOBC), West Palearctic Regional Section (WPRS) standard protocols. Twelve selected fungicides were studied in the doses (g or ml active ingredient/100 L) captan 1 (0.115), captan 2 (0.120), kresoxim-methyl (0.010), sulphur 1 (AG) (0.480), sulphur 2 (0.480), folpet (0.105), mancozeb (0.160), pyraclostrobin (0.010), tebuconazole (0.010), tetraconazole (0.005), thiophanate-methyl (0.050) and triforine (0.024). Distilled water was used as the blank treatment and the insecticide triclorfon (0.150) as a positive control. The parasitoids were exposed to dry residues applied on glass plates. The reduction in the capacity of parasitism was used to measure the effect of the chemical in comparison to the blank treatment. Each treatment was replicated four times. The results allowed us to classify the fungicides tested in four categories: 1, harmless (< 30%); 2, slightly harmful (30-79%); 3, moderately harmful (80-99%); and 4, harmful (> 99%). 75% of the tested substances were classified as selective (classes 1 and 2) to the parasitoid. The fungicides captan 1, captan 2, kresoximmethyl, folpet, pyraclostrobin, tebuconazole, thiophanate-methyl and triforine were harmless; mancozeb was slightly harmful; sulphur 1 (AG) and tetraconazole were moderately harmful and sulphur 2 was harmful. These findings should be taken into account when selecting fungicides to spray apple orchards against fungi diseases to preserve the egg parasitoid T. pretiosum.KEY WORDS: Insecta, egg parasitoid, pesticide, Malus domestica, Integrated Fruit Production RESUMO -Este trabalho objetivou avaliar a susceptibilidade em condições de laboratório de adultos do parasitóide de ovos Trichogramma pretiosum Riley a fungicidas utilizados na Produção Integrada da Maçã (PIM). Os bioensaios foram conduzidos utilizando-se protocolos padrões da Organização Internacional para o Controle Biológico (IOBC), Seção Regional Paleártica Oeste (WPRS). Foram testados doze fungicidas nas respectivas doses (g ou ml ingrediente ativo/100 L) captana 1 (0,115), captana 2 (0,120), cresoxim-metílico (0,010), enxofre 1 (AG) (0,480), enxofre 2 (0,480), folpete (0,105), mancozebe (0,160), piraclostrobina (0,010), tebuconazol (0,010), tetraconazol (0,005), tiofanato-metílico (0,050) e triforina (0,024). Adicionalmente, utilizou-se água destilada como testemunha negativa e o inseticida triclorfom (0,150) como testemunha positiva. Adultos do parasitóide foram expostos a resíduos dos tratamentos depositados sobre placas de vidro, sendo avaliadas as reduções no parasitismo em relação à testemunha (somente água). Cada tratamento teve quatro repetições. Os resultados permitiram classificar os fungicidas quanto ao impacto sobre os parasitóides em quatro classes: 1, inócuo (< 30%); 2, levemente nocivo (30-79%); 3, mod...

Side Effects of Fungicides Used in Cucurbitaceous Crop on Trichogrammaatopovirilia Oatman & Platner (Hymenoptera: Trichogramatidae)

“…On other hand, mancozeb not affect the parasitism of T. atopovirilia on D. hyalinata eggs. Similar reduction in the parasitism was observed with Trichogramma pretiosum in A. kuehniella eggs with mancozeb and tebuconazole (Manzoni et al, 2006). However, mancozeb was harmless to T. pretiosum in A. kuehniella eggs (Giolo et al, 2007), such as T. atopovirilia in D. hyalinata eggs.…”

“…On other hand, pesticides may limit the efficiency of biological control agents. Fungicides, herbicides and plant growth regulators can have deleterious effects on parasitoids Trichogramma, although pesticides not have a specific site of action in arthropods, but these products can induce sublethal effects on reproduction and other biological function (Manzoni et al, 2006;Stefanello Júnior et al, 2008). Studies of selectivity generate information that helps the decision in IPM and maintenance of beneficial organisms in the agroecosystem (Degrande et al, 2002;Moura et al, 2005).…”

Seletividade de herbicidas registrados para a cultura do milho a adultos de Trichogramma pretiosum (Hymenoptera: Trichogrammatidae)

“…No Brasil, estudos de seletividade de agrotóxicos a Trichogramma foram conduzidos predominantemente para frutíferas e olerícolas (Castelo Branco & França, 1995;Carvalho et al, 2003;Giolo et al, 2005b;Manzoni et al, 2006aManzoni et al, , 2007Morandi Filho et al, 2006;Moura et al, 2006), e poucos foram os trabalhos em culturas anuais (Hohmann, 1993;Cañete, 2005), sobretudo na cultura do milho, em que somente alguns inseticidas foram avaliados (Cruz, 1995;Pratissoli et al, 2004). Assim, na maioria dessas culturas, poucos trabalhos foram realizados visando avaliar a seletividade de herbicidas a inimigos naturais.…”

Application of ethanolic extract of propolis typified in nutrition and vegetative growth of beans

“…The expansion in these agricultural areas and the fragility of its harvest have been facing pest and disease attacks. Application of agricultural defensives and fertilizers has generated negative effects in the water quality, throughout the accumulation of pesticides molecules, plant equilibration and the natural biological control (Manzoni et al, 2006;Gama et al, 2013).…”

“…The expansion in these agricultural areas and the fragility of its harvest have been facing pest and disease attacks. Application of agricultural defensives and fertilizers has generated negative effects in the water quality, throughout the accumulation of pesticides molecules, plant equilibration and the natural biological control (Manzoni et al, 2006;Gama et al, 2013).Due to the detriment of the use of pesticides and nutrients, many researchers have evaluated various alternatives to replace the use of chemicals, like grout, raw cow's milk, milk whey, cow urine, biological insecticide based on Bacillus thuringiensis, Bordeaux mixture, melted coconut soap and vegetable extracts (Zatarim et al, 2005;Sousa et al, 2012). However, the current alternatives are few; hence there is a need to provide new options and have more studies about the benefits of the use of its alternatives (Pereira et al, 2008).…”