Repellency, Anorexia, and Aversion by Neonicotinoid-Treated Seeds and Cotyledons on Birds.

ADDY ORDUNA L.; CAZENAVE J. ; MATEO SORIA R.

Congreso; VII Setac Latin America 14 Biennal Meeting.; 2021

SETAC

Farmland birds can be exposed to neonicotinoids used for seedtreatment through the ingestion of unburied seeds and cotyledons. Theaim of this study was to evaluate the avoidance (through repellency,anorexia, and/or conditioned aversion) of sorghum and soybean seeds,and soybean cotyledons treated with imidacloprid, clothianidin orthiamethoxam on eared doves (Zenaida auriculata) by one-choice testsin captivity. The doves were exposed to the treatments (control vs.neonicotinoid-treated sorghum, soybean or cotyledons, plusmaintenance food) for 3-5 days to study the repellency of the treatedseed and anorexia, followed by a 7-day period on maintenance food tostudy the persistence of the anorexic effect after neonicotinoid exposure.Right after, the same doves were exposed to treated food during asecond period of 3-5 days to study the repellency and/or the conditionedaversion after the previous exposure. Finally, doves were exposed to therespective untreated type of food to study the conditioned food aversionindependently of the treatment. Intoxication signs, differences of bodyweight and other adverse effects also were determined. With sorghum,the three neonicotinoids produced a marked repellent effect, decreasingthe consumption of treated seeds by >97% compared to control birds.However, this repellency was not enough to prevent the death of 3/8 and1/8 of the doves exposed to imidacloprid and clothianidin, respectively.Imidacloprid-treated soybeans caused a significant repellent effect, butthis was not observed for the cotyledons. Signs of anorexia were onlyobserved against the neonicotinoid-treated sorghum. The birds did notavoid the untreated seeds after exposure to the treated ones, suggestingthe importance of the color, odor or taste to cause the repellence and theabsence of a conditioned aversion. In conclusion, seed avoidance causedby neonicotinoids at the recommended application doses was strong, butit failed to prevent intoxication and death on eared doves in the case ofexposure to treated sorghum seeds.