Lethal and behavioral effects of selected novel pesticides on adults of Trichogramma pretiosum (Hymenoptera: Trichogrammatidae)

Abstract

Most novel pesticides, except for several insecticides, exhibited little to no acute toxicity to the parasitoid. Parasitoid foraging behavior was only affected by tolfenpyrad, indicating that parasitoids could successfully forage on eggs treated with most pesticides evaluated. Therefore, many of these pesticides may have good compatibility with Trichogramma.

Lethal effects of selected novel pesticides on immature stages of Trichogramma pretiosum (Hymenoptera: Trichogrammatidae)

“…Abamectin, dinotefuran (both formulations), fipronil, novaluron, spinetoram, and tolfenpyrad were particularly toxic relative to the other compounds. These results corresponded with our previous results with adult T pretiosum …”

“…In the few studies of the effects of glufosinate ammonium on egg parasitoids, this herbicide was generally reported to adversely affect these parasitoids, although the effects are typically moderate . These results align with observations on immature stages and previously on adults of T. pretiosum .…”

“…The objective of this study was to evaluate the lethal effects of selected pesticides (including insecticides, miticides, herbicides, and fungicides) on immature stages of the parasitoid T. pretiosum and the success of parasitoid emergence from treated host eggs. These results complement a previous study of most of these same pesticides with adult T. pretiosum …”

“…found that trifloxystrobin, pyraclostrobin, and tebuconazole did not significantly affect emergence of Telonomus remus Nixon compared with controls and were, therefore, all ranked as harmless to immature stages of the parasitoid. We previously found no lethal adverse effect of these fungicides on adult T pretiosum …”

An update of the Worldwide Integrated Assessment (WIA) on systemic insecticides. Part 2: impacts on organisms and ecosystems

“…By contrast, another Pteromalidae parasitoid, Urolepis rufipes, did not show that behavior with either neonicotinoid tested (Burgess and King 2016). In semi-field tests designed to evaluate the toxicity of 19 new insecticides applied at label rates to cotton on the egg parasitoid Trichogramma pretiosum, fipronil (480 ppm) and dinotefuran (1040 ppm) showed almost 100% mortality in 24 h, whereas acetamiprid (429 ppm) caused 80% mortality (Khan et al 2015). Similarly, imidacloprid applied at the label rate on citrus trees (40 ppm) is harmful to the encyrtid parasitoid Ageniaspis citricola, causing over 89% mortality in 24 h and having residual activity on the leaves up to 17 days (de Morais et al 2016b).…”