How single events can influence decision‐making in foraging Vespula germanica (Hymenoptera: Vespidae) social wasps

Abstract

Social insects are known for their behavioural plasticity and learning abilities. In the present work, we evaluated whether a single past experience could influence Vespula germanica (F.) foraging behaviour by analysing wasp response in two changing situations: when food was displaced at different distances from a previously learned location and when the amount of resource was significantly decreased. In the former case, wasps were allowed to collect meat once from a dish which was later displaced 300, 600 or 900 mm from the previous location. Thus, on the second visit, wasps encountered an empty dish in place of the previously baited one. We recorded the time taken to find the displaced food, the number of hovers over the previously learned location and the direction of first approach of returning foragers. Wasps spent less time searching at the previously learnt site when the dish with food was displaced 300 mm rather than 600 or 900 mm from the learned location. In the second experiment, when two dishes with food were simultaneously offered, one containing 20 g and another 80 g, wasps preferred the 80 g dish. On their second visit, we switched the position of the dishes and recorded which dish wasps collected food from. We found that most wasps collected food from the previously learned location and not from the dish with the more abundant resource. This study illustrates the remarkable influence of a single collecting experience on V. germanica subsequent foraging behaviour.

How behavioral plasticity enables foraging under changing environmental conditions in the social waspVespula germanica(Hymenoptera: Vespidae)

“…For instance, after food was removed, returning wasps remembered the exact site where food was originally placed on their first visit (Lozada & D'Adamo, 2006, 2011). A similar pattern is observed even when food is displaced at a short distance (such as 30 cm) away from the previously learned site (Moreyra & Lozada, 2018). Since wasps take, on average, about 8.4 min (SE: ±0.78, n = 90) to return to the previously rewarded site (Moreyra et al ., 2014), it is highly improbable that any trails of mince meat odor remained at the experimental area after this lapse of time; however, it is desirable that future studies confirm this hypothesis.…”

“…short distance (such as 30 cm) away from the previously learned site (Moreyra & Lozada, 2018). Since wasps take, on average, about 8.4 min (SE: ±0.78, n = 90) to return to the previously rewarded site (Moreyra et al, 2014), it is highly improbable that any trails of mince meat odor remained at the experimental area after this lapse of time; however, it is desirable that future studies confirm this hypothesis.…”

“…Living beings are constantly facing impermanent milieus; experience is always changing and depends on particular contextual situations (Varela, 2000). The invasive social wasp Vespula germanica displays complex behavioral processes while collecting food in ever‐changing anthropized environments (D'Adamo & Lozada, 2011; Lozada & D'Adamo, 2011, 2014; Moreyra et al ., 2012, 2016; Pietrantuono et al ., 2017; Moreyra & Lozada, 2018). As a social insect, when a forager wasp finds an abundant food source, it makes numerous trips between the resource and the nest where larvae are fed (Beugnon et al ., 2001; Toh & Okamura, 2003; Lozada & D'Adamo, 2014).…”

“…Although numerous investigations have studied social insects’ responses when contextual cues are modified (e.g., Graham & Cheng, 2009; Wilson‐Rankin, 2015; Freas & Cheng, 2017, 2018; Collett & Zeil, 2018; Freas & Spetch, 2019), to our knowledge, little research has evaluated how these species respond to modifications of food location (e.g., Toh & Okamura, 2003; Graham et al ., 2007; Cheng et al ., 2012; Czaczkes & Heinze, 2015). It has been shown that even a first collecting visit can impact on subsequent foraging performance by hindering the perception of food in a novel site (e.g., Toh & Okamura, 2003; Durier et al ., 2004; Graham et al ., 2007; Lozada & D'Adamo, 2014; Moreyra & Lozada, 2018). For example, in Vespa mandarinia , it has been found that when the resource is displaced or removed from the learned location, hornets spend some time searching for food in the previously collected site (Toh & Okamura, 2003).…”

“…Diverse studies in V. germanica have shown that foragers always return to the exact place where food was previously located; that is, wasps fly directly to the resource, without displaying any searching behavior over the array (e.g., D'Adamo & Lozada, 2011, 2014; Moreyra et al ., 2012, 2016; Lozada & D'Adamo, 2014; Moreyra & Lozada, 2018). The fact that wasps are able to memorize food locations having visited the site only once was also observed when food was completely removed (Lozada & D'Adamo, 2006, 2011) and even when it was displaced 30 cm away from the learned site (Moreyra & Lozada, 2018). Interestingly, a recent study revealed that when two dishes with different amounts of meat were simultaneously offered, wasps preferred to collect food from the dish with more quantity.…”