An evaluation of the effects of deltamethrin on two non-target lizard species in the Karoo, South Africa

We measured the effects of deltamethrin, a pyrethroid insecticide, on individuals of two lizard species,Meroles suborbitalis and Pedioplanis namaquensis, in enclosures under controlled conditions, and under field conditions. We found significant effects on lizard mortality rates in the enclosure experiments, with most lizards dying within two months of treatment. Our field-based investigation, conducted over a five-month period, revealed significant reductions in abundance of M. suborbitalis (reduced by 52%) and P. namaquensis, (reduced by 72%) one and four weeks after spraying with deltamethrin. At 18 weeks after spraying there was no longer a significant difference in abundance measures between treatment and control plots, due to the invasion of the plots by juveniles.