New experimental techniques for studying root herbivores.

Abstract

This chapter focuses on recent developments in non-invasive methods for studying root herbivores, both in the field (acoustic detection) and in the laboratory (X-ray tomography). It focuses on these two non-invasive techniques because they seem to offer the most potential for investigating root herbivory, based on recent studies using a range of root feeders. Other non-invasive methods for studying subterranean herbivores exist (e.g. telemetric techniques), but detailed studies concerning their usage remain scarce, and are therefore not covered in this chapter. Only the rootfeeding insects are discussed in this chapter because these techniques cannot yet be properly exploited for smaller root herbivores such as nematodes, and are probably inappropriate for larger root herbivores such as rodents. A full glossary of the terms used in the text is given.

Biology and management of the redheaded pasture cockchaferAdoryphorus couloni(Burmeister) (Scarabaeidae: Dynastinae) in Australia: a review of current knowledge

“…A range of non-invasive techniques could be developed to study these interactions (Mankin et al 2008). Radiographic X-ray techniques, which produce two-dimensional images, have been used to determine the effect of physical soil properties, soil temperature and soil moisture on other scarab species (Villani & Wright 1988).…”

A simple in vitro method to study interactions between soil insects, entomopathogenic fungi, and plant extracts

“…Data collected with this approach quantify soil insect activity during entire observation periods rather than providing snapshot evidence of an insect's position at a certain census date, as given in earlier studies. There are methods available which are even better suited to reflect the natural situation in soil, as they allow to observe soil insect behaviour in three dimensional spaces, like x-ray (Mankin et al, 2008) or acoustic techniques (Johnson et al, 2007). Their approach revealed larval position at a defined moment but left uncertainty about the activity in between census dates.…”

“…Nevertheless, attempts have been made to get insight into soil pest insects' behaviour and ecology (van Herk & Vernon, 2007;Johnson et al, 2007;Mankin et al, 2008;Schumann et al, 2013). For this purpose, wireworm activity was assessed under choice and no-choice situations with single and combined treatments of the EPF and the garlic extract.…”

“…For this purpose, wireworm activity was assessed under choice and no-choice situations with single and combined treatments of the EPF and the garlic extract. However, they often rely on special, usually expensive, technical equipment and training (Mankin et al, 2008). Recent studies have shown that the failure of wireworm control measures are attributable to the ignorance of the behavioural responses of the pest insects to treatments.…”

“…Studying such mechanisms in soil pests is particularly difficult due to their cryptic lifestyle. Nevertheless, attempts have been made to get insight into soil pest insects' behaviour and ecology (van Herk & Vernon, 2007;Johnson et al, 2007;Mankin et al, 2008;Schumann et al, 2013). All of these set-ups have their advantages and drawbacks.…”