**Author details**

duce the number of applications by managing crops so that they are less likely to become infested. This approach will obviously reduce the number of insecticide applications, and therefore also decrease the likelihood of pest populations developing resistance. In this con‐ text, it is also important to highlight the adverse effect of insecticides on populations of ben‐ eficial insects. The example given here is for adverse effects on dung feeding beetles which provide ecosystem services by dispersing and burying dung and reducing populations of dung breeding nuisance flies. Avermectins are a family of drugs used to control internal parasites of cattle, horses and sheep. Residues from these compounds that are excreted in the dung of cattle can kill both the dung breeding nuisance fly pest, *Musca vetustissima,* and adversely affect the breeding of introduced scarab dung beetles [95]. Several authors have expressed concern that widespread use of avermectins as cattle drenches could adversely af‐ fect the populations of recently introduced scarab dung beetles [96]. Research has shown that scarab dung beetles in southern Australia breed mainly for 2-3 months in spring, and if farmers avoid using avermectins to drench cattle in these critical months an impact on dung beetle breeding would be minimised [97]. As can be seen from these examples, it is necessa‐ ry to have a good biological and ecological understanding of the pest and the crop plant in

222 Insecticides - Development of Safer and More Effective Technologies

order to optimise the control of pests and reduce adverse effects of using insecticides.

When concerns are raised about efficacy of currently available pest management programs, it is important to remember that humans have battled arthropod pests for as long as we have had agricultural production. There are 4,500-year old records of insecticide-based man‐ agement practices for control of insect pests in pre- and post-harvest agricultural products. Even biological control has been practiced for over 2,000 years [58, 59]. Yet, we have not been able to develop arthropod pest management Systems based on pesticide applications, which consistently (across many growing seasons and in most growing regions) maintain individual pest species below densities of economic concern. In stored grain, orchards, horti‐ culture, row crops. As a consequence, we are today researching management programs for the same pests as we did 50-100 years ago, or even before that. Despite incredible technolog‐ ical advances and scientific innovations during the development of human civilizations, we are still unable to "outsmart" the insects and mites in our food production, processing, and storage systems. On the other hand, there are several important examples of how classical biological control has provided almost complete control of different pests (i.e. weevils to control water hyacinth infestations in rivers and lakes, parasitoids to control cassava mealy‐ bugs in Western Africa, and moths to control prickly pear in Australia). Transgenic Bt tech‐ nology may be considered an encouraging exception, as it has provided remarkable control of several key coleopteran and lepidopteran pests with high levels of resistance to other in‐ secticides. However, even here there is widely reported documentation of Bt resistance (http://www.pesticideresistance.com/irac.php), and/or examples of how secondary pests, unaffected by Bt toxins, have adapted and taken advantage of the absence of Bt-controlled competitors. Thus for growers, Bt may have solved one pest problem but at the same time

**10. Conclusions**

Christian Nansen\* and Thomas James Ridsdill-Smith

\*Address all correspondence to: christian.nansen@uwa.edu.au

The University of Western Australia, School of Animal Biology and the UWA Institute of Agriculture, Perth, Western Australia, Australia
