Bioatividade de produtos fitossanitários utilizados na cultura do tomateiro (Lycopersicon esculentum Mill.) a Trichogramma pretiosum Riley, 1879 (Hymenoptera: Trichogrammatidae) nas gerações F1 e F2

Abstract

GILBERTO CASADEI BAPTISTA2 RESUMO A bioatividade de dezoito produtos quími-cos utilizados no controle de pragas e doenças do tomateiro, sobre duas linhagens de Trichogramma pretiosum Riley, 1879 (L 9 =Alegre, ES e L 10 = Venda Nova do Imigrante, ES), nas gerações F 1 e F 2 , foi investigada em laboratório. Ovos de Anagasta kuehniella (Zeller) contendo o parasitóide em diferentes estágios de desenvolvimento (ovo-larva, pré-pupa e pupa) foram tratados por meio de imersão nas respectivas caldas químicas. Os inseticidas triflumuron, clorfluazuron, deltametrina, Bacillus thuringiensis, lambdacialotrina, teflubenzuron, acefato, pirimicarb e ciromazina, e os fungicidas benomil, iprodiona, clorotalonil e dimetomorf, independente da linhagem, não reduziram a longevidade das fêmeas de T. pretiosum da geração F 1. Os inseticidas abamectin, cartap, metamidofós e lambdacialotrina afetaram a razão sexual de indivíduos da geração F 1, e não reduziram a taxa de emergência de parasitóides da F 2 , independente do estágio de desenvolvimento e da origem da população de T. pretiosum. Parasitóides de Venda Nova do Imigrante, ES (L 10 ) mostraram-se mais susceptíveis que os de Alegre, ES (L 9 ) aos efeitos dos compostos avaliados. De modo geral, a fase de pupa de T. pretiosum, independente da população, apresentou maior tolerância aos produtos testados. Recomenda-se a realização de novos testes para outras populações desse parasitóide que serão utilizadas no controle de pragas, pois podem responder de forma diversa aos produtos fitossanitários avaliados. TERMOS PARA INDEXAÇÃO:Trichogramma, pesticidas, seletividade, tomate. BIOACTIVITY OF PESTICIDES USED IN TOMATO (Lycopersicon esculentum MILL.) CROP TO Trichogramma pretiosum Riley, 1879 (HYMENOPTERA: TRICHOGRAMMATIDAE) IN F 1 AND F 2 GENERATIONS ABSTRACTThe bioactivity of eighteen pesticides commonly used to pests and diseases control on tomato, in two strains of Trichogramma pretiosum Riley, 1879 (L 9 =Alegre, ES and L 10 = Venda Nova do Imigrante, ES, Brazil) in F 1 and F 2 generations, was evaluated under laboratory conditions. The bioassays were conducted in a climatic chamber at 25 2 o C, 60 10% RH and 14 hours of photophase. Eggs of Anagasta kuehniella (Zeller) containing the parasitoid in different phases of development (egg-larva, pre-pupa and pupa) were treated by immersion in aqueous dilutions of the products. The insecticides triflumuron, chlorfluazuron, deltamethrin, Bacillus thuringiensis, lambdacyalothrin, abamectin, cartap and methamidophos, did not decrease the longevity of females T. pretiosum in F 1 generation independently of the parasitoid strain. Abamectin, cartap, methamidophos and lambdacyalothrin affected the sexual ratio in F 1, and did not decrease the emergence of parasitoids in F 2 generation, independently of stage of development and origin. The L 10 strain was more susceptible to all pesticides as compared to L 9 . The pupal stage of T. pretiosum was more tolerant to the products, independently of its origin. It is recommended new tests with other strain...

Impact of insecticides used to control Spodoptera frugiperda (J.E. Smith) in corn on survival, sex ratio, and reproduction of Trichogramma pretiosum Riley offspring

“…It is believed that the highest longevity values observed for females exposed to pyrethroid-treated host eggs are related to their repellent effect on this parasitoid species. This effect was also verified by Carvalho et al (2001), who found that T. pretiosum females avoided contact with pyrethroid-treated host eggs. Etofenprox is likely to have caused the same repellent effect since it exhibits a similar chemical structure to that of pyrethroidbased insecticides (Yoshimoto et al, 1989;Weerasinghe et al, 2001;Gunning et al, 2007).…”

“…Spinosad reduced in 90.7% the parasitism capacity, 1 h after treatment, and was considered moderately harmful (class 3); however, parasitism capacity of tested females decreased in 79.5% and 78.6% at 24 and 48 h after treatment, respectively, and was classified as slightly harmful (class 2) ( Table 1). It is believed that the observed reductions in parasitism capacity of T. pretiosum exposed to pyrethroid-based insecticides can also be associated with their repellent effect as reported by Carvalho et al (2001) and/or to inhibition of parasitism behavior caused by these compounds for this parasitoid species.…”

Toxicity of some insecticides used in maize crop on Trichogramma pretiosum (Hymenoptera, Trichogrammatidae) immature stages

“…The highest reduction caused by beta-cypermethrin, chlorfenapyr, chlorpyrifos, and spinosad in the emergence success of T. pretiosum (F1) from treated host eggs containing the egg-larval period can be associated to the higher activity of the larval stage, as well as to the capacity of some chemicals to penetrate through the host chorion, exposing the larvae to a higher contact with these compounds and affecting the parasitoid development (Guifen and Hirai, 1997;Schuld and Schumuck, 2000;Carvalho et al, 2001;Cônsoli et al, 2001;Moura et al, 2005;. It is also supposed that the highest toxicity presented by beta-cypermethrin, chlorfenapyr, chlorpyrifos, and spinosad to T. pretiosum can be related to their octanol-water partition coefficient (log Kow) values (6.60, 4.83, 4.7, and 2.8, respectively), which give to these compounds higher lipophilicity and, consequently, high residues in the chorion of the host egg.…”

Avaliação De Metodologias Para Testes De Seletividade De Inseticidas Reguladores De Crescimento a Trichogramma Pretiosum (Riley, 1879) (Hymenoptera: Trichogrammatidae) Na Cultura Da Macieira Em Condições De Laboratório

“…Carvalho et al (2002), também verificaram que o inseticida Match quando pulverizado em ovos de A. kuehniella reduziu significativamente a emergência de T. pretiosum. Resultados opostos encontrou Canete (2005), verificando que o número de adultos de T. atopovirilia emergidos destes ovos foi estatisticamente maior nos tratamentos com reguladores de crescimento em relação à testemunha.…”

“…A utilização destes produtos é referida como componente viável em programas de manejo de pragas (Narayana & Babu, 1992). Estudos anteriores têm demonstrado a seleletividade destes produtos a parasitóides de ovos (Bull & Coleman, 1985, Zaki & Gesraha, 1987, Cônsoli et al, 1998, Carvalho et al, 2002, Carvalho et al, 2003, Canete, 2005.…”