Nutrient Dynamics of a Swarm‐founding Social Wasp Species, Polybia occidentalis (Hymenoptera: Vespidae)

Abstract

The kinds, rates of acquisition, inter‐individual transfers, and intra‐colonial movements of nutrients were ascertained for the advanced eusocial paper wasp Polybia occidentalis (Olivier). Foraging worker wasps (“foragers”) bring arthropod prey and nutritive liquids (“nectar”) to the nest, and these are usually transferred to nest workers (“receivers”) on the outer nest envelope. Arthropod prey items, which are brought intact to the nest, are malaxated by one or more receivers before being fed to larvae; malaxating adults retain a portion of the hemolymph for their own nourishment. Nectar is usually transferred (via adult‐adult torphallaxis) from foragers to receivers on the nest envelope; some nectar is given to larvae, and all adults that imbibe it retain at least some for their own nourishment. Larval saliva of P. occidentalis contains glucose, protein, and free amino acids and so is highly nutritive; the nutrient content of the saliva closely resembles that of the saliva of other social wasp taxa. Adult wasps imbibe larval saliva, but very little is apparently transferred by those adults (via trophallaxis) to nestmates. Brood cannibalism was infrequent during this study. Adult worker and male wasps possess chymotrypsin‐like and trypsin‐like enzyme in their midguts and so are likely capable of protein digestion. The midgut proteases show an age‐correlated variation in concentration. Pulp foragers are significantly smaller and lighter in weight than are receivers.

Nest thermoregulation in Polybia scutellaris (White) (Hymenoptera: Vespidae)

“…The nest temperature (approximately 27°C) was similar to that of vespine nests (28-30°C;Himmer 1927, Ishay 1973, Martin 1990, 1992, whereas the temperature in the abandoned nest was almost similar to the T a throughout the day, indicating heat generation (thermogenesis) by the individuals of the colony, as observed in several social insects (Seeley & Heinrich 1981). Although nest cooling activities have been observed in swarm-founding epiponine wasps (Hunt et al 1987, 1995, Jeanne 1991), very few cases are known reporting the occurrence of the incubation behavior (Yamane et al 2009). To the best of our knowledge, this is the first study to report nest incubation by Polybia species.…”

Pollen content accumulated in nests ofPolybia scutellaris(Hymenoptera, Vespidae)

“…Brood care is cooperative and larvae are fed by means of progressive provisioning (Hunt et al, 1987). According to Bruch (1936), the colony becomes active in spring (October) and the floral visits end in May.…”

Resource Storage in the Neotropical Social Wasp Mischocyttarus socialis (Saussure, 1854) (Vespidae: Polistini)

“…Resource storage in social wasps is seen as a reflex of the group's opportunistic foraging habit in response to sporadically abundant food sources (Richards & Richards, 1951); stored food is an important complement to the colony's diet, especially during dry seasons, when resources are usually scarce (Hunt et al, 1987).…”