Sociality in spiders

Abstract:

After insect sociobiology emerged as a discipline in its own right (Hamilton, 1964; Wilson, 1971), a number of social insect species were discovered that had been previously unknown to science. Aoki (1976) and Crespi (1992a, b) described unusual patterns of social behavior in the plant-feeding aphids and thrips, respectively. Among their many species, a small number express patterns of social organization resembling those found in some other eusocial animals. These are the eusocial aphids and thrips, and while they are not closely related (i.e. they are in separate orders in an ancient insect group within the superorder Paraneoptera, Grimaldi & Engels, 2005), they share a number of convergent social traits, the most important being that they form defense-based social groups composed reproductives and defenders, or “soldiers”. The discoveries of this and the research that followed accompanied a renewed enthusiasm for broadly comparative approaches in social evolution (Choe & Crespi, 1997), a legacy that this and other recent volumes share. Because social aphids and thrips share a number of features, considering them jointly provides insights into the evolution of defense-based societies in insects (Table 6.1, Figure 6.1). Unlike eusocial insects like the ants, which are both ecologically and- judging by their persistence in the fossil record, evolutionarily successful-the rarity of sociality in aphids and thrips implies that the conditions for the emergence of complex social traits are not common in either group. Like the cooperatively breeding birds or mammals, however, it is the uniqueness of sociality that invites comparative analyses of traits that vary between social and non-social taxa. Crespi, et al. (2004) reviewed the ecology and evolution of Australian Acacia thrips, including sociality in this group, and pointed to several convergent aspects of sociality in thrips and aphids. In his recent book The Other Social Insects, Costa (2006) provided broad overviews of the biology of social aphids and thrips, as well as a diversity of other minor social insects. Our goal for this chapter is to focus mainly on the evolutionary transitions both have made to eusociality, leaving aside the variety of cooperative behaviors that non-eusocial species express. In contrast to most other groups reviewed in this volume, the body of research on aphids and thrips remains relatively young and uneven.

Año de publicación:

2017

Keywords:

Fuente:

scopus