Chronic exposure to chlorpyrifos reveals two modes of action in the springtail Folsomia candida
Jager, T., Crommentuijn, T., Gestel, C. A. M. van and Kooijman, S. A. L. M.
2007.
Chronic exposure to chlorpyrifos reveals two modes of action in the springtail Folsomia candida
Environ. Pollut., 145: 452 - 458
Abstract
Organophosphates are popular insecticides, but relatively little is
known about their chronic effects on ecologically relevant
endpoints. In this paper, we examine a life-cycle experiment with the
springtail Folsomia candida, exposed via food to chlorpyrifos
(CPF). The results for all endpoints (survival, growth and
reproduction) were analyzed using the DEBtox model. Growth was
unaffected by CPF, even at concentrations causing severe effects on
survival and reproduction. Model analysis suggests that CPF directly
affects the process of egg production. For the short-term response (45
days), this single mode of action accurately agreed with the
data. However, the full data set (120 days) revealed a dose-related
decrease in reproduction at low concentrations after prolonged
exposure, not covered by the same mechanism. It appears that CPF
interacts with senescence by increasing oxidative damage. This
assumption fits the data well, but has little consequences for the
predicted response at the population level.