Dissipation kinetics of imidacloprid in cotton flower, nectariferous tissue, pollen and Apis mellifera products using QuEChERS method

Abstract

BACKGROUND: Exposure of Apis mellifera to neonicotinoid insecticides is one of the factors attributed to the recent decline in A. mellifera populations resulting in economic and ecological losses due to loss of pollination services. Honey bees can get exposed to neonicotinoids like imidacloprid directly in the field at the time of application as well as during consumption of pollen and nectar from treated plants. So, the fate of imidacloprid in commodities to which honey bees get exposed needs to be overhauled. RESULTS: Residue of imidacloprid was investigated following imidacloprid application as seed treatment (2.4 and 4.8 g a.i. kg -1 seed) at the time of sowing and as foliar spray (17.8 and 35.6 g a.i. ha -1 ) at 70 days after sowing when the crop was at full bloom stage. The imidacloprid residue was below limit of quantification (LOQ) in flowers, necatariferous tissue, pollen from seed-treated cotton plants and honey collected from hives kept in plots with seed-treated cotton plants. However, average initial imidacloprid residue (2 h after spray) was 1.84 and 1.95 mg kg −1 in flowers; 0.22 and 0.24 mg kg −1 in nectariferous tissue; 0.88 and 0.96 mg kg −1 in pollen collected from plants sprayed with imidacloprid @ 17.8 g a.i. ha −1 at locations Faridkot and Bathinda, respectively. The average initial imidacloprid residue (21 days after spray) in honey collected from hives was 0.01 mg kg −1 . CONCLUSION: The residue in different substrates sampled from seed treated cotton plants was below LOQ. However, its foliar spray at bloom time resulted in imidacloprid residue in flower, nectariferous tissue, pollen and honey sampled from hives placed in plots.

Oxytetracycline Increases the Residual Risk of Imidacloprid in Radish (Raphanus sativus) and Disturbs the Plant-Rhizosphere Microbiome Holobiont Homeostasis

“…IMI was a systemic pesticide, which was easily absorbed by plants. Kaur Brar et al reported that IMI residue was 1.95 mg/kg in cotton flowers and 0.24 mg/kg in nectariferous tissue after IMI was sprayed . The concentration ranges were close to those in this experiment.…”

“…Kaur Brar et al reported that IMI residue was 1.95 mg/kg in cotton flowers and 0.24 mg/kg in nectariferous tissue after IMI was sprayed. 31 The concentration ranges were close to those in this experiment. The half-life of IMI was about 3−7 days in crop, for example, capsicum, and the degradation rate was relatively high.…”

Matrine can be absorbed and transmitted bidirectionally to defend against aphids (Hemiptera: Aphididae) on wheat and pepper

“…For example, the contents of imidacloprid sprayed were different in cotton flowers, leaves, nectary tissues and pollens, being highest in leaves, but not detected in the nectary tissues and pollens after seed treatment. 4,25 Thiamethoxam could be absorbed by roots and transported upwards rapidly to control sucking mouthparts pests, but difenoconazole without root absorption was used only to control rice diseases by stem and leaf spray. [26][27][28] Surprisingly, this study showed that matrine could be rapidly absorbed by the roots, leaves and seeds of both pepper and wheat, and transmitted into all organs.…”

“…Moreover, different systemic pesticides have different transmission directions in plants – upwards, downwards or bidirectionally – and their conduction modes, velocities and biological concentrations are different when treating different plant organs. For example, the contents of imidacloprid sprayed were different in cotton flowers, leaves, nectary tissues and pollens, being highest in leaves, but not detected in the nectary tissues and pollens after seed treatment 4,25 . Thiamethoxam could be absorbed by roots and transported upwards rapidly to control sucking mouthparts pests, but difenoconazole without root absorption was used only to control rice diseases by stem and leaf spray 26–28 .…”

Mobility and Degradation of Pesticides in Soil-Risk to Groundwater Contamination

“…Also, there have been concerns about the pesticide in context to the occupational hazards, residues in food and water above the permissible limit even though these are manufactured under strict regulation to function with certainty and minimal effect on non-target organisms (Damalas and Eleftherohorinos, 2011). There are reports of exposure of non-targent organisms like pollinators to pesticides resulting in economic and ecological losses (Brar et al, 2022). So, it becomes important to have vast knowledge about the nature of pesticide to be applied, their movement in soil and various tactics to prevent their risk to non-target organisms.…”