Effect of increasing rate of insecticides on its selectivity for Trichogramma pretiosum Riley (Hymenoptera: Trichogrammatidae)

Abstract

The present study evaluated the effect of different rates of chlorantraniliprole, chlorantraniliprole + lambda-cyhalothrin, spinosad, and chlorfenapyr on their selectivity for the pupae and adults of Trichogramma pretiosum. The negative effect of majority of the insecticides tested on most of the parasitoids was directly proportional to the rate of the insecticide applied. Chlorantraniliprole at a rate of 10 g a.i. ha -1 was classified as harmless (class 1) to both pupae and adults of the parasitoid. The effect of chlorantraniliprole at a rate of 20 to 50 g a.i. ha -1 varied from harmless (class 1) to slightly harmful (class 2) to the adults of T. pretiosum. Chlorantraniliprole 10 + lambda-cyhalothrin at 5 g a.i. ha -1 was classified as harmless (class 1) to the pupae and moderately harmful (class 3) to the adults of T. pretiosum. On the contrary, the highest rate of chlorantraniliprole 50 + lambda-cyhalothrin tested (i.e., 25 g a.i. ha -1 ) was classified as slightly harmful (class 2) to the pupae and harmful (class 4) to the adults of the parasitoid. Similarly, increasing the application rate of spinosad and chlorfenapyr also exhibited an increase in toxicity. Spinosad at a rate of 24 g a.i. ha -1 was classified as slightly harmful (class 2) and harmless (class 1) to the pupae and adults of T. pretiosum, respectively. Spinosad at 96 g a.i. ha -1 was classified as both moderately harmful (class 3) and harmful (class 4) to the pupae of the parasitoid. Chlorfenapyr at a rate of 192 g a.i. ha -1 was classified as both slightly harmful (class 2) and moderately harmful (class 3) to the pupae of T. pretiosum, whereas chlorfenapyr at 336 g a.i. ha -1 was categorized as slightly harmful (class 3) and harmful (class 4) to the pupae. These results indicate that an increase in the rate of insecticide affected T. pretiosum negatively. Therefore, higher insecticide rates should only be adopted when strictly necessary to control the target pest, because they might compromise the biological pest control process in the field. ResumoO presente estudo avaliou o efeito de diferentes taxas de clorantraniliprole, clorantraniliprole + lambdacialotrina, espinosade, e clorfenapir na seletividade para as pupas e adultos de Trichogramma pretiosum. O efeito negativo da maioria dos inseticidas testados nos parasitoides foi diretamente proporcional à dose do inseticida aplicado. O clorantraniliprole na dose de 10 g a.i. ha -1 foi classificado como seletivo (classe 1) para pupas e adultos do parasitoide. O efeito do clorantraniliprole na dose de 20 a 50 g a.i. ha -1 variou de seletivo (classe 1) a levemente prejudicial (classe 2) aos adultos de T. pretiosum. Clorantraniliprole 10 + lambda-cialotrina a 5 g a.i. ha -1 foi classificado como seletivo (classe 1) para as pupas e moderadamente prejudicial (classe 3) aos adultos de T. pretiosum. Ao contrário, a dose mais alta de clorantraniliprole 50 + lambda-cialotrina testada (isto é, 25 g a.i. ha -1 ) foi classificada como moderadamente prejudicial (classe 3) para as pupas e nociva (cla...

Toxicidade de inseticidas registrados para uso em cana-de-açúcar ao parasitoide >i<Trichogramma galloi >/i<(Hymenoptera: Trichogrammatidae)

“…por ovo da praga (LOPES, 1988). Para o controle de Helicoverpa zea (Boddie, 1850) (Lepidoptera: Noctuidae) em milho, Sá (1991) sugere a razão de 10,7 T. pretiosum por ovo da lagarta, enquanto que, na cultura da soja, Zachrisson (1997) 1997). Este gênero possui cerca de 210 espécies descritas (PINTO, 2006).…”

“…O T. galloi foi criado e multiplicado em ovos de A. kuehniella fornecidos pela empresa Koppert Biological Systems Brasil localizada no município de Charqueada-SP, que utiliza dieta a base de farinha de trigo integral (97%) e levedura de cerveja (3%), metodologia está proposta por Parra (1997). Esta espécie de traça, além de melhor aceita, proporciona um melhor desenvolvimento para espécies de Trichogramma (PARRA et al, 1991).…”

“…Apesar da fase de pupa ser considerada a fase de maior resistência à ação de inseticidas (HASSSAN, 1992 Em estudos semelhantes sobre a fase de pupa de parasitoides o inseticida clorantraniliprole foi considerado inócuo a T. podisi (STECCA et al, 2018), T pretiosum (PAIVA et al, 2018;GRANDE et al, 2018) e T. chilonis (KHAN, 2019).…”

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

“…For the laboratory tests, it is also important to expose the least susceptible stage, i.e., the pupae inside the host egg, in the case of a parasitoid (Hassan 1998, Grützmacher et al 2004. Several studies have tested the effects of insecticides on pupae of Trichogramma species, some by dipping the host eggs containing the pupae (Consoli et al 1998, Carvalho et al 2003, Moura et al 2005, Chen et al 2013, and some by spraying the host eggs (Momanyi et al 2012, Costa et al 2014, Grande et al 2018. However, none of these studies compared these different methods, dipping versus spraying.…”

“…However, none of these studies compared these different methods, dipping versus spraying. Moreover, only a few studies have assessed the transgenerational effects (Carvalho et al 2003, Costa et al 2014, Grande et al 2018.…”