toxics Review Fate of Pyriproxyfen in Soils and Plants James Devillers CTIS, 3 Chemin de la Gravière, 69140 Rillieux-La-Pape, France;
[email protected] Received: 17 February 2020; Accepted: 10 March 2020; Published: 13 March 2020 Abstract: Since the 1990s, the insect growth regulator pyriproxyfen has been widely used worldwide as a larvicide in vector control and in agriculture to fight a very large number of pests. Due to its widespread use it is of first importance to know how pyriproxyfen behaves in the terrestrial ecosystems. This was the goal of this work to establish the fate profile of pyriproxyfen in soils and plants. Thus, in soil, pyriproxyfen photodegrades slowly but its aerobic degradation is fast. The insecticide presents a high tendency to adsorb onto soils and it is not subject to leaching into groundwater. On the contrary its two main metabolites (40-OH-Pyr and PYPAC) show a different fate in soil. When sprayed to plants, pyriproxyfen behaves as a translaminar insecticide. Its half-life in plants ranges from less than one week to about three weeks. The review ends by showing how the fate profile of pyriproxyfen in soils and plants influences the adverse effects of the molecule on non-target organisms. Keywords: pyriproxyfen; soil; plant; metabolites; insect growth regulator; endocrine disruptor; terrestrial ecosystems 1. Introduction The behavior of pesticides in soils is under the dependence of physical, chemical, and biological processes including volatilization, sorption–desorption, aerobic and anaerobic degradation, uptake and release by plants, run-off, and leaching. These various complex processes control the transport of pesticides within the soil and their transfer from the soil to the other environmental compartments [1–3].