Suitability of (extra-)floral nectar, pollen, and honeydew as insect food sources

Abstract

Introduction Although arthropod predators and parasitoids are usually associated with their carnivorous qualities, they often require plant-provided foods as well, at least during part of their life cycle. The level in which predators or parasitoids depend on these plant-provided foods varies (see Wäckers and van Rijn, Chapter 1). Temporal omnivores and permanent omnivores are facultative consumers of plant-derived food, using it as complement to their prey. This category includes mites (Bakker and Klein 1992b), spiders (Ruhren and Handel 1999), hemipterans (Bugg et al . 1991), beetles (Larochelle 1990; Pemberton and Vandenberg 1993; Pfannenstiel and Yeargan 2002), lacewings (Limburg and Rosenheim 2001), wasps (Beggs 2001), and ants (Porter 1989). Life-history omnivores, on the other hand, are obligatory consumers of plant-provided foods during certain stages (usually the adult stage). This means that they are entirely dependent on non-prey food for their survival and metabolic upkeep. Examples are syrphid flies (Lunau and Wacht 1994), some lacewings (Canard 2001), and many parasitoids (Jervis et al . 1996) and ants (Porter 1989; Tobin 1994). Ants play a key role in the evolution of a range of food-mediated mutualisms, including extrafloral nectar, food bodies, elaiosomes, Lycaenid dorsal gland secretions and certain honeydews (see also Koptur, Chapter 3). The degree in which ants depend on these foods varies widely. The dietary requirements of ants range from species that are primarily predaceous, to species that rely almost entirely on honeydew and extrafloral nectar.