Abstract
This chapter considers the effect of drought and temperature (low and high) stress directly on the aphid and the plant, and the indirect consequences of stress on the host plant on this important insect herbivore group. Studies of stress effects on aphids have focused largely on temperature, in particular examining and categorizing the responses of aphids, with less focus on the underlying physiological and molecular causes. In contrast, there has been less examination of the effects of drought on aphids. It is often the case that secondary effects such as changes in nutrition induced by temperature or drought are the focus, rather than the underling primary physiological effects of the stress. Thus, studies of aphids do not parallel the more physiological approach taken in the study of the responses of their host plants to the same stresses. The burgeoning molecular toolkit that is now available is a new opportunity to uncover the mechanisms by which aphids adapt to, or are damaged by, stress; these approaches are facilitated by the availability of the aphid genome sequence, and it is to be hoped that further research effort in these areas will qualitatively move forward our understanding of aphids' response to stress.