Tests for Evaluating the Side Effects of Chlorothalonil (TPN) and Spinosad on the Parasitic Wasp (<i>Aphidius colemani</i>)

Abstract

To better understand the side-effects of pesticides on nontarget insects, exposure and mortality assessment tests were performed with the parasitic wasp, Aphidius colemani. Quantities of chlorothalonil (TPN) and spinosad in individual wasps were determined using commercially available ELISA kits. TPN showed no side-effect on contact with dry film or oral administration. The lethal dosage of spinosad on plant leaves was estimated at ca. 0.2 mg/cm 2 for individual wasps, and was supported by the results of residual activity tests. Furthermore, a minimum of around 0.1 ng of spinosad was observed in dead individuals exposed to plant leaves treated with a lethal dosage of the posticide.

The non‐target impact of spinosyns on beneficial arthropods

“…In contrast to predators, spinosad caused severe lethal effects towards all tested species, irrespective of the exposure route used. When testing the recommended field rates for specific crops in which a given natural enemy can occur, 100% mortality in adults was observed for Aphidius colemani Viereck, Aphytis melinus DeBach, Coccophagus lycimnia Walker, Leptomastix dactylopii (Howard) and Diadegma insulare (Cresson) after 24 h of exposure to dried residues of spinosad on inert materials 72, 74–76. Similar results were reported for Trichogramma chilonis Ishii adults when exposed to host eggs or tomato leaves previously treated with the field recommended rate 77.…”

Laboratory evaluation of the side effects of insecticides on Aphidius colemani (Hymenoptera: Aphidiidae), Aphidoletes aphidimyza (Diptera: Cecidomyiidae), and Neoseiulus cucumeris (Acari: Phytoseidae)

“…Similarly, spinosad and pyridaben were classified as slightly harmful to A. aphidimyza and N. cucumeris and were harmful to A. colemani. The high toxicity of spinosad on A. colemani was also found by Takahashi et al (2005), when tested in similar bioassay at rate 0.1 g l -1 . Different results were obtained when formulated azadirachtin A (NeemAzal T/S) and pure azadirachtin A were tested against A. colemani.…”

“…Similarly, no data have been published till present on the side effects of methoxyfenozide or acetamiprid against beneficial species from the family Aphidiidae. Inconsistent results have been published on the side effects of indoxacarb (Dinter and Wiles 2000;Bostanian and Akalach 2004) and spinosad Takahashi et al 2005) against Aphidiidae, azadirachtin A against Cecidomyidae (Spollen and Isman 1996) and pyridaben (Shipp et al 2000;Hardman et al 2006) and propargite (Shipp et al 2000) against Phytoseidae.…”

Fungicides affect Japanese beetle Popillia japonica (Coleoptera: Scarabaeidae) egg hatch, larval survival and detoxification enzymes

“…The chloronitriles, specifically the active ingredient chlorothalonil, and the demethylation inhibitor (DMI) fungicides are commonly and frequently applied to amenity turfgrass for disease management. The results of studies on insects with chloronitrile fungicides are varied, with some reporting toxicity of chlorothalonil and other studies reporting no toxicity . The exact mechanism of toxicity is unknown, but chlorothalonil has been reported to bind to sulfhydryl enzymes, which are important for cellular respiration, bind and deplete cellular glutathione (GSH) and inhibit glycolysis by binding with glyceraldehyde 3‐phosphate dehydrogenase (GAPDH) .…”

“…The results of studies on insects with chloronitrile fungicides are varied, with some reporting toxicity of chlorothalonil 6 and other studies reporting no toxicity. 7,8 The exact mechanism of toxicity is unknown, but chlorothalonil has been reported to bind to sulfhydryl enzymes, which are important for cellular respiration, bind and deplete cellular glutathione (GSH) and inhibit glycolysis by binding with glyceraldehyde 3-phosphate dehydrogenase (GAPDH). 9 Demethylation inhibitor fungicides can decrease the activity of P450 enzymes in insects, 10,11 which are important for growth, reproduction, hormone synthesis and detoxification of foreign chemical compounds.…”