ABSTRACT

I review and summarize the scattered information on embiids (Order Embiidina), with an emphasis on details of colony structure and maternal care. I summarize experimental and observational field results from a detailed study on parental and communal behavior of Antipaluria urichi, a Trinidadian webspinner. Topics discussed include the function of maternal behavior, interactions with egg parasitoids, antipredator attributes of communal living, and possible functions of silk. I also compare features of webspinner sociality to other communal insects and spiders. In addition, I discuss promising topics for future study, including male dimorphism, the possibility of higher sociality, and communication systems.

INTRODUCTION

Webspinners (Order Embiidina or Embioptera) construct a nest–like structure, exhibit parental care, and commonly live in the tropics where overlapping generations may occur. These attributes represent factors that allow for the evolution of complex social interactions in insects (Evans 1977; Eickwort 1981), making embiids an intriguing order with many research questions yet to be addressed. This cosmopolitan order, including 850 mostly tropical species in 14 families (E. S. Ross, personal communication), has been classified within the Orthopteroidea, which includes earwigs, cockroaches, walkingsticks, mantids, katydids, crickets, grasshoppers and termites (Hennig 1981). In a more recent phylogenetic treatment of hexapod orders (Minet and Bourgoin 1986), Embiidina and Zoraptera are sister–groups within the Polyneoptera, which includes all the orders mentioned above, plus Plecoptera. Boudreaux (1979) also proposed a close phylogenetic relationship between Plecoptera and Embiidina.