Quantification of Imidacloprid Uptake in Maize Crops

Abstract

The systemic imidacloprid is one of the most used insecticides in the world for field and horticultural crops. This neurotoxicant is often used as seed-dressing, especially for maize, sunflower, and rape. Using a LC/MS/MS technique (LOQ = 1 microg/kg and LOD = 0.1 microg/kg), the presence of imidacloprid has been measured in maize from field samples at the time of pollen shed, from less than 0.1 microg/kg up to 33.6 microg/kg. Numerous random samples were collected throughout France from 2000 to 2003. The average levels of imidacloprid measured are 4.1 microg/kg in stems and leaves, 6.6 microg/kg in male flowers (panicles), and 2.1 microg/kg in pollen. These values are similar to those found previously in sunflower and rape. These results permit evaluation of the risk to honeybees by using the PEC/PNEC ratios (probable exposition concentrations/predicted no effect concentration). PEC/PNEC risk ratios were determined and ranged between 500 and 600 for honeybees foraging on maize treated with imidacloprid by seed dressing. Such a high risk factor can be related to one of the main causes of honeybee colony losses.

A nicotinic acetylcholine receptor agonist affects honey bee sucrose responsiveness and decreases waggle dancing

“…It is translocated primarily within the xylem and is absorbed by different plant tissues (Sur and Stork, 2003). Nectar and pollen can consequently contain imidacloprid at concentrations that negatively affect honey bees (Bonmatin et al, 2003;Bonmatin et al, 2005). In addition, the guttation drops (xylem sap) that exude on the tips and edges of corn leaves grown from pesticide-treated seeds can contain high levels of pesticide (Girolami et al, 2009).…”

The influence of sublethal doses of imidacloprid on protein content and proteolytic activity in honey bees (Apis mellifera L.)

“…Colonies from group BE (control) were given food free from imidacloprid, while the food administered to colonies from group BE-5 and BE-200 was contaminated with 5 and 200 ppb of imidacloprid, respectively. The concentrations of 5 and 200 ppb were chosen, firstly because they are both sublethal, and secondly because they represent an average of field realistic concentrations: the 5 ppb for pollen and nectar (Bonmatin et al, 2003(Bonmatin et al, , 2005 and the 200 ppb for guttation drops (Tapparo et al, 2011). The bees were fed with both bee syrup (Apifortuna) and pollen patties made from fresh pollen loads and inverted syrup Apifortuna in the ratio of 2.5:1.4.…”

Residu Pestisida pada Madu Apis cerana di Kawasan Hortikultura

“…Kemampuan analisis spektrometri kromatografi cair tandem (LC / MS-MS) yang lebih baru dikembangkan sangat penting untuk pestisida sistemik yang lebih baru, terutama neonicotinoids (Bonmatin et al, 2005;Chauzat et al, 2006). Residu sistemik yang lebih tua, seperti metabolit sulfur-oksidasi beracun aldicarb, banyak fungisida dan herbisida modern, dan degradasi polar fungisida dan herbisida yang lebih baru tidak dapat dianalisis pada batas ppb deteksi tanpa LC / MS-MS (Alder et al, 2006).…”