INTRODUCTION

Social wasps (Hymenoptera: Vespidae) exhibit a diversified diet that includes plant-derived products, such as the pulp of Myrtaceae fruits (^{Souza, Venâncio y Prezoto et al., 2010}; Souza et al., 2013; ^{Brügger, Castro, Prezoto, Serrão y Zanuncio, 2017}; ^{Nucci & Alves-Junior, 2017}; ^{Lourido, Somavilla, Barbosa y De Vasconcelos, 2024}; ^{Renne, Costa, Jacques y Souza, 2024}). This plant family has significant ecological and economic importance worldwide. However, few studies have investigated the potential damage caused by social wasps during fruit development in economically important species, such as jaboticaba Plinia cauliflora (Mart.) (e.g., Souza et al., 2010). Consequently, our understanding of the interactions between these insects and Myrtaceae species may be incomplete.

Plinia cauliflora typically produces fruit twice annually and can suffer significant losses from various insects that feed on fruit pulp, rendering the fruit unsuitable for consumption and commercialization (^{Sanábio y Franco Júnior, 2023}). Therefore, this study aimed to inventory and monitor social wasp activity during a reproductive period of P. cauliflora in an urban area of southeastern Brazil.

MATERIALS AND METHODS

The study was conducted between September and November 2024 on an adult P. cauliflora tree located at a private residence (21°01'24"S, 44°19'12"W) in the urban area of Ritápolis municipality, Minas Gerais, Brazil.

Observations were conducted during four distinct phenological phases: (1) flowering, during the last week of September; (2) fruit maturation stage I, when the first fruits began to ripen while most remained immature (November 1-3); (3) fruit maturation stage II, when nearly all fruits had ripened (November 9-11); and (4) post-maturation, when few fruits remained and these were partially desiccated (November 15-17).

Approximately 25 non-consecutive hours of behavioral observations were conducted using ad libitum sampling between morning and afternoon periods. Social wasps were identified by MMS using taxonomic keys (^{Richards, 1978}; ^{Andena, Carpenter y Noll, 2009}; ^{Andena & Carpenter, 2012}; ^{Brito, Oliveira, Carpenter y Somavilla, 2024}). Voucher specimens were collected for taxonomic confirmation.

RESULTS AND DISCUSSION

Thirteen species of social wasps were recorded feeding on jaboticaba fruit pulp, but no species was observed visiting flowers (Table 1, Figure 1).

Figure 1 Social wasp species foraging on P. cauliflora fruits. A - S. cyanea; B - P. platycephala; C - P. fastidiosuscula; D - P. ignobilis; E - P. chrysothorax; F - P. bifasciata. Photo credit: G. C. S. Oliveira. 

During maturation stage I, two social wasp species were observed: S. cyanea and P. platycephala, with only individuals of the former species able to penetrate the fruit skin. Maturation stage II exhibited the highest wasp species richness, with 11 species recorded. Notably, P. fastidiosuscula and P. chrysothorax were also capable of breaking through the jaboticaba fruit peel.

Five species were recorded during the post-maturation stage, particularly P. scutellaris, which was exclusively observed during this phase. Additionally, only S. cyanea and P. ignobilis foraged on fallen fruit; all other species consumed fruit that remained attached to the tree.

Jaboticaba fruits can serve as a significant nutritional resource for social wasps in anthropically altered environments with limited food availability. Beyond their high sugar content (^{Fortes et al., 2011}), jaboticaba fruits provide vitamin C, fiber, various minerals, and polyphenols (^{Destro et al., 2019}).

During jaboticaba fruit development, sugar levels increase while acidity decreases (^{Fortes et al., 2011}). Furthermore, enhanced production of essential oils occurs during fruit maturation (Fortes et al., 2011), which wasps may use to locate potential food resources, as these insects rely on olfactory cues during foraging (^{Yossen, Buteler y Lozada, 2022}). These factors may explain the higher number of social wasp species recorded during maturation stage II, similar to patterns reported for guava and other fruit consumption by these insects (^{Renne et al., 2024}).

Only P. platycephala was present throughout the entire fruiting period, which may reflect two conditions: first, the colony's proximity to the jaboticaba tree, reducing foraging costs and maximizing energy efficiency; and second, a generalist and opportunistic diet, as this species also feeds on diverse prey in urban areas (^{Prezoto, Maciel, Detoni, Mayorquin y Barbosa, 2019}).

Conversely, S. cyanea and P. scutellaris occurred exclusively during stages Maturation I and Post-maturation, respectively, which can also be attributed to their foraging behavior in altered environments, as these species exploit various resources (^{Prezoto et al., 2019}).

Synoeca cyanea has been previously reported feeding on different fruits (^{Brügger, Souza, Souza y Prezoto, 2011}; ^{Rocha et al., 2023}). Although recorded only at the beginning of the fruit ripening process (Maturation I), its presence was crucial for resource utilization by other social wasp species and even other insects (^{Lourido et al., 2024}), as it was one of three species capable of penetrating fruit skin.

Of the species recorded in this study, only five had been previously documented feeding on jaboticaba fruit pulp: B. lecheguana, P. occidentalis, P. ignobilis, P. sericea, and S. cyanea (^{Souza et al., 2010}). The remaining eight species therefore represent novel records for P. cauliflora fruit consumption. However, most of these species had been observed foraging on commercial fruits of other Myrtaceae species, including pitanga Eugenia uniflora L. (Souza et al., 2013), gabiroba Campomanesia adamantium (Cambess.) O. Berg (^{Nucci & Alves-Junior, 2017}), araçá Psidium sp. (^{Brügger et al., 2011}), guava Psidium guajava L. (^{Lourido et al., 2024}; ^{Renne et al., 2024}), and rose apple Syzygium jambos (L.) Alston (Brügger et al., 2017).

Previous studies have not documented damage to Myrtaceae fruits: ^{Souza et al. (2013}) suggested that social wasp visitation to pitanga likely represented searches for pest larvae, while ^{Nucci & Alves-Junior (2017}) recorded some social wasp species visiting gabiroba flowers. Other studies have documented potential damage by social wasps to healthy or ripe fruit. However, ^{Renne et al. (2024}) demonstrated that damage occurs only to overripe guava fruit with no commercial value.

Beyond potential damage to Myrtaceae fruits, social wasps, particularly those capable of penetrating fruit skin such as S. cyanea, have been observed damaging mangoes (Anacardiaceae) (^{Rocha et al., 2023}) and grapes (Vitaceae) (^{Hickel & Schuck, 1995}). This suggests these insects may be undesirable for certain crops, with colony removal near affected crops recommended (^{Souza et al., 2010}). Conversely, alternative management approaches are suggested in the literature, as social wasps provide valuable biological control of crop pests (^{Prezoto et al., 2019}), supporting colony retention in agricultural areas.

A less impactful alternative involves applying homemade insecticides prepared by farmers using tobacco-based solutions (Solanaceae), according to EMBRAPA Environment guidelines (^{Watanabe & Melo, 2006}). These treatments can repel wasps during specific fruiting stages, thereby reducing fruit damage while preserving their beneficial pest control services.

CONCLUSIONS

This study documented 13 Vespidae species utilizing jaboticaba fruit as a food resource in urban environments. Despite documented fruit damage, we recommend deterring social wasps only during the fruit ripening period, while avoiding colony translocation or destruction in cultivation areas, given the potential value of these insects for biological pest control. We suggest that future studies should quantify the economic impact of jaboticaba fruit consumption by social wasps to better inform integrated pest management strategies.