Sublethal effects of insecticides used in soybean on the parasitoid Trichogramma pretiosum

Abstract

To control crop pests, parasitoid wasps of the genus Trichogramma are one alternative to the use of insecticides. Since a wide variety of agrochemicals may be applied to the same crops, it is essential to assess the selectivity of insecticides used for pest control on Trichogramma pretiosum. Information on which insecticides are less harmful to T. pretiosum can improve biological control using this insect, an important tactic in IPM programs for field crops. This study aimed to determine the effects of insecticides on the pupal stage and on the parasitism capacity of T. pretiosum. Lambda-cyhalothrin + thiamethoxam were slightly harmful and chlorpyriphos was moderately harmful to the pupal stage, while acephate, chlorfenapyr and flubendiamide, although considered innocuous, affected the succeeding generations of wasps, with low emergence of F. Chlorfenapyr, chlorpyriphos and lambda-cyhalothrin + thiamethoxam reduced the parasitism, and acephate had a deleterious effect on the generation that contacted the insecticide residue. For an effective IPM program, it is important to apply selective insecticides. Further studies are needed to determine the selectivity of these insecticides under field conditions.

Differential impacts of pesticides on Euschistus heros (Hem.: Pentatomidae) and its parasitoid Telenomus podisi (Hym.: Platygastridae)

“…The effect of insecticides on the parasitoid longevity will depend on the type of insecticide, parasitoid species, and the mode of insecticide application 40 . For instance, these reductions in longevity are commonly observed in parasitoids emerged from eggs exposed to pesticides while developing inside the host 32,57 . However, Beserra and Parra 53 found no significant changes in the longevity of F 1 females of Trichogramma pretiosum Riley (Hymenoptera: Trichogrammatidae) developing in eggs of Anagasta kuehniella (Zeller) (Lepidoptera: Pyralidae) treated with lambda-cyhalothrin in the larval, pre-pupal, and pupal stages of the parasitoid.…”

“…Previous studies evaluated the differential acute toxicity of pesticides against the target pests and their natural enemies in different crops with the aim of choosing a pesticide with a high degree of lethal toxicity on pests and minimal non-target lethal toxicity 28–30 . In addition to direct pesticide-induced mortality, the sublethal effects must be considered for a complete impact analysis, helping pesticide choice for IPM 31,32 . However, to the best of our knowledge, no studies to date compared the acute toxicity of pesticides on E .…”

Parasitoid Wasp Community Dynamics in Vineyards Following Insecticide Application

“…Laboratory experiments have been used to test the effects of Indoxacarb on specific parasitoid wasp species, and it has been shown to be harmful to Cotesia plutellae Kurdjumov, 1834, a larval endoparasitoid, in the adult stage (Haseeb et al, 2004), adult Trichogramma pretiosum Riley, 1879, an egg parasitoid (Scholz and Zalucki 2000), and Aphidius colemani Viereck, 1912 adults, which parasitize aphids (Bostanian and Akalach 2004). Fecundity and longevity of females were also reduced in C. plutellae and species in the genus Trichogramma (Haseeb et al, 2004;de Paiva et al, 2018;Gallego et al, 2019). Effects on emergence after insecticide application on immature stages varied among studies.…”

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

“…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).…”

“…Diferentemente dos resultados obtidos no presente estudo, Beloti et al (2018) classificaram os inseticidas lambda-cialotrina + clorantraniliprole e lambda-cialotrina + Nos três intervalos de tempos (5, 15 e 30 DAP) avaliados os inseticidas clorantraniliprole, triflumurom, tebufenozida e novalurom não provocaram nenhuma alteração na longevidade (k= 60,63; g.l= 7; p<0,0001) (k= 100,29; g.l= 7; p<0,0001) (k= 54,48; g.l= 7; p<0,0001) e capacidade de parasitismo (k= 54,9; g.l= 7; p<0,0001) (k= 72,98; g.l= 7; p<0,0001) (k= 38,04; g.l= 7; p<0,0001) da geração F0 (Tabela 16), assim como na emergência (χ2= 51,09; g.l= 7; p<0,001) (χ2= 25,39; g.l= 7; p<0,001) (χ2= 37,16; g.l= 7; p<0,001)e razão sexual (χ2= 4,57; g.l= 7; p=0,08) (χ2= 8,72; g.l= 7; p=0,008)(χ2= 17,73; g.l= 7; p<0,001) da geração F1 (Tabela 17). Esses inseticidas não provocaram efeitos expressivos nos testes de laboratório, por isso já eram esperados resultados positivos.…”