Foraging niche separation of social wasps in an invaded area: Implications for their management

Abstract

Foraging niche separation may be a mechanism to promote coexistence of two competing species by concentrating intraspecific competition relative to interspecific competition. The present study investigated foraging behaviour and microhabitat use of two coexisting species of invasive social wasps, Vespula germanica and Vespula vulgaris, when foraging for two different food resources. Also, we tested the attractiveness of traps baited with a synthetic lure for those two species. We found that V. germanica wasps prefer to forage at ground level regardless of the resource, while V. vulgaris prefers protein resources at the shrubland level given a choice between a protein bait at ground or at shrubland level. However, when baited with the synthetic lure, the species caught was not affected by the height at which traps were placed. That is, in a no choice scenario, the traps were sufficiently attractive to lure both species of wasps to both microhabitats (ground and shrubland levels). Thus, our results support the existence of spatial niche differentiation at least in protein foraging and suggest that the synthetic lure evaluated could be used to trap both species of Vespula wasps present in Argentina. These results could help to improve management strategies of these social wasps in an invaded area.

Long-term coexistence of two invasive vespid wasps in NW Patagonia (Argentina)

“…Given their similarity in biology, and overlap in nesting sites and diet, these species may have developed strategies to avoid or reduce competition. In New Zealand and Patagonia, it has been noted that both species have spatial resource partitioning, where V. vulgaris were found foraging in the shrubland, mid height level while V. germanica were more commonly seen foraging at the ground level (Harris et al 1991;Masciocchi et al 2019). In line with this, Pereira et al (2016) found that V. germanica significantly avoids V. vulgaris visual and odour cues in bioassays with free-flying wasps arriving to protein baits.…”

“…Even though both species are seen as generalists, their diet and phenology are very similar, suggesting an overlap in food preferences and foraging behavior (mainly protein-rich foods) towards the end of summer and autumn when colonies need to feed future reproductive individuals (gynes and males; Sackmann et al 2000). Moreover, feeding activities observed for both wasp species may be disrupted by each other's presence, suggesting that these two species could interfere between each other (Masciocchi et al 2019). It has been suggested that differences in the foraging strategies displayed by these wasps may render V. vulgaris with a competitive advantage over V. germanica in certain scenarios (Harris et al 1994;Pereira et al 2016).…”

Biogeography and anthropogenic impact shape the success of invasive wasps on New Zealand's offshore islands

“…Measuring wasp abundance can be challenging; especially in areas with low wasp densities. Attraction of wasps to baited traps is highly variable (e.g., Harris, Moller, & Tilley, 1991;Masciocchi, Unelius, & Buteler, 2019). Density estimates using Malaise traps and nest searching in strip plots are correlated, suggesting that these non-baited methods are relatively robust for estimating wasp abundance (Beggs et al, 1998 Plunkett, & Harris, 1990).…”

Sensory niche partitioning in two sympatric social wasps: sugar responsiveness could determine foraging patterns in yellowjackets

“…Examples from New Zealand and Argentina (Patagonia) indicate that these wasps spatially partition resources. Vespula vulgaris tends to forage in shrubland at mid canopy-height levels, while V. germanica is more commonly found at ground level 23,24 . Moreover, on the northeast coast of New Zealand, differences in the diet of V. vulgaris and V. germanica have been observed across different seasons 25 .…”