Determination of lead toxicity in Culex quinquefasciatus mosquitoes in the laboratory.
Laboratory investigations were carried out to study the effects of lead toxicity and lead uptake on Culex quinquefasciatus mosquitoes. Three different concentrations of lead nitrate were used in laboratory tests (0.05, 0.1, and 0.2 mg/l). An atomic absorption spectrometer (AAS) was used to the determine lead concentrations. The results showed that lead significantly reduced hatching, egg-production, and emergence rates, compared with the unexposed group (p < 0.05). The ratio of female to male offspring was 3.64:1, which was observed in the second generation, after the parents were exposed to 0.2 mg/l lead. No effects were observed on oviposition preference, larval weight, or larval deformation. The LC50 of lead against Cx. quinquefasciatus larvae within 24 hours was 0.18 mg/l. There was a significant increase in lead uptake related to increased lead exposure in mosquito larvae (p < 0.05). The bioconcentration factor (BCF) showed that the lead concentration in the larvae was 62 times greater than in the water. The lead concentration from parents to offspring reduced in the first and second generations (p < 0.05). There was no significant difference between female and male mosquitoes in lead concentration (p > 0.05).
Kitvatanachai
Sirima
S
Department of Medical Entomology, Faculty of Tropical Medicine, Mahidol University, 420/6 Rajvithi Road, Bangkok 10400, Thailand. sirima@rangsit.rsu.ac.th
Apiwathnasorn
Chamnarn
C
Leemingsawat
Somjai
S
Wongwit
Waranya
W
Tornee
Songpol
S
D000818:Animals; D003465:Culex / Q000187:drug effects* / Q000378:metabolism / Q000502:physiology; D004784:Environmental Monitoring; D005260:Female; D007753:Laboratories; D007814:Larva / Q000378:metabolism; D007854:Lead / Q000633:toxicity*; D008297:Male; D009566:Nitrates / Q000633:toxicity*; D012098:Reproduction; D012744:Sex Ratio; D013785:Thailand; D014876:Water Pollution
D009566:Nitrates; D007854:Lead; C017461:lead nitrate