The Toxicological Effects and Bioaccumulation of Fipronil in Larvae of the Mosquito Aedes aegypti in Aqueous Medium

Toxicity and Bioaccumulation of Fipronil in the Nontarget Arthropodan Fauna Associated with Subalpine Mosquito Breeding Sites

“…The biomass of Chaoboridae larvae is far higher than that of Crustacea. Moreover, the integumental route of insecticide penetration into these larvae may be of very low importance, much less than that observed in larval mosquitoes (Chaton et al, 2001). This particular performance of larval Chaoboridae against "pronil may be reinforced by their active predatory diet (Durieu and Thomas, 1995), which contrasts with the passive suspension feeding habits of planktonic Crustacea and with the detritivorous diet of larval Culicidae (Clements, 1992).…”

“…However, ingestion has been evidenced to be the main means of insecticide bioaccumulation in mosquito larvae, which may be enhanced by using appropriate food (Chaton et al, 2001). Under such conditions, researching on a selective absorption of "pronil by target larval mosquitoes through feeding together with avoiding di!usion of the insecticide molecules throughout the aquatic medium is of interest.…”

“…In summary, three types of comportments can be observed among the species studied. (1) In the case of A. robustus and D. castor as well as of larval C. annularius and Aedes aegypti (Chaton et al, 2001), "pronil penetration from the water solution into the body is easy, allowing the toxic e!ect to appear at a low insecticide concentration. Di!erences in the LC obtained among those species may result from speci"c biodistribution patterns, or various metabolization rates, or even from speci"c sensitivity of the target.…”

“…In the aquatic environment, preliminary evaluations in laboratory (Ali et al, 1998) and in the "eld (Ali et al, 1999;Sulaiman et al, 1997) have suggested a possible use of "pronil against larval culicine and chironomid midge species resistant to other insecticides. At present, "pronil appears to be one of the most e!ective synthetic insecticides for mosquito larvae control (Chaton et al, 2001). Bioaccumulation studies have indicated a low direct bioavailability in the aquatic environment, in addition to a low-rate integumental route for penetration into larvae.…”

“…Bioaccumulation studies have indicated a low direct bioavailability in the aquatic environment, in addition to a low-rate integumental route for penetration into larvae. Moreover, importance of the digestive route for insecticide accumulation into larvae has suggested that ingestion might be the best way of "pronil administration to mosquito larvae (Chaton et al, 2001).…”