Imidacloprid

Ecotoxicology: 
Algae: E_rC₅₀ for Pseudokirchneriella subcapitata >100 mg/l.Bees:Harmful to honeybees by direct contact, but no problems expected when not sprayed into flowering crop or when used as a seed treatment.Birds:Acute oral LD₅₀ for Japanese quail 31, bobwhite quail 152 mg/kg. Dietary LC₅₀ (5 d) for bobwhite quail 2225, mallard ducks >5000 mg/ kg.Daphnia: LC₅₀ (48 h) 85 mg/l.Fish: LC₅₀ (96 h) for golden orfe 237, rainbow trout 211 mg/l.Worms: LC₅₀ for Eisenia foetida 10.7 mg/ kg dry soil. 

Environmental fate: 
Imidacloprid is highly toxic to honeybees by direct contact and harmful to insects in general, including predatory insects such as ladybirds and lacewings. Imidacloprid is slightly toxic to juvenile and adult fish and to aquatic invertebrates. The product appears to repel birds when used as a seed treatment.

Fate in soil:
Imidacloprid displays a medium absorption to soil and some degree of mobility, although leaching into deeper soil layers is not to be expected. In soil, imidacloprid is degraded continuously but not very rapidly; the product does not accumulate and is not persistent and the maximum concentrations in soil during long-term trials under unfavourable conditions reached a plateau level and declined in the absence of further applications. Imidacloprid has a half-life of 27 days in silt loam sediment under anaerobic conditions. Upon exposure to light, imidacloprid had a half-life of 39 days on sandy loam soil and the product is stable to hydrolysis at acid-neutral Ph under exclusion of light. The main routes of degradation of imidacloprid are photodegradation and microbial activity.

Fate in aquatic systems:
Imidacloprid degrades readily in the presence of light and the product rapidly undergoes degradation in water via photolytic reactions or microbial activity. Upon exposure to light, imidacloprid has a half-life of one hour in water.