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Agrochemicals pose significant threats to the survival of bees, yet the physiological impacts of sublethal doses on stingless bees remain poorly understood. This study investigated the effects of acute oral exposure to three commercial formulations of agrochemicals [CuSO 4 (leaf fertilizer), glyphosate (herbicide), and spinosad (bioinsecticide)] on antioxidant enzymes, malondialdehyde content (MDA), nitric oxide (NO) levels, and total hemocyte count (THC) in the stingless bee Partamona helleri. Foragers were exposed to lethal concentrations aimed to kill 5% (LC 5 ) of CuSO 4 (120 μg mL -1 ) or spinosad (0.85 μg mL -1 ) over a 24-h period. Glyphosate-exposed bees received the recommended label concentration (7400 μg mL -1 ), as they exhibited 100% survival after exposure. Ingestion of CuSO 4 or glyphosate-treated diets by bees was reduced. Levels of NO and catalase (CAT) remained unaffected at 0 h or 24 h post-exposure. Superoxide dismutase (SOD) activity was higher at 0 h compared to 24 h, although insignificantly so when compared to the control. Exposure to CuSO 4 reduced glutathione S-transferase (GST) activity at 0 h but increased it after 24 h, for both CuSO 4 and glyphosate. MDA levels decreased after 0 h exposure to CuSO 4 or spinosad but increased after 24 h exposure to all tested agrochemicals. THC showed no difference among glyphosate or spinosad compared to the control or across time. However, CuSO 4 exposure significantly increased THC. These findings shed light on the physiological responses of stingless bees to agrochemicals, crucial for understanding their overall health., (© 2024. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

There are multifactorial causes for the recent decline in bee populations, which has resulted in compromised pollination and reduced biodiversity. Bees are considered one of the most important non-target insects affected by insecticides used in crop production. In the present study, we investigated the effects of acute oral exposure to spinosad on the survival, food consumption, flight behavior, respiration rate, activity of detoxification enzymes, total antioxidant capacity (TAC), brain morphology, and hemocyte count of Apis mellifera foragers. We tested six different concentrations of spinosad for the first two analyses, followed by LC 50 (7.7 mg L -1 ) for other assays. Spinosad ingestion decreased survival and food consumption. Exposure to spinosad LC 50 reduced flight capacity, respiration rate, and superoxide dismutase activity. Furthermore, this concentration increased glutathione S-transferase activity and the TAC of the brain. Notably, exposure to LC 50 damaged mushroom bodies, reduced the total hemocyte count and granulocyte number, and increased the number of prohemocytes. These findings imply that the neurotoxin spinosad affects various crucial functions and tissues important for bee performance and that the toxic effects are complex and detrimental to individual homeostasis., (© 2023. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Microplastics (MPs) are widespread pollutants of emerging concern, and the risks associated with their ingestion have been reported in many organisms. Terrestrial environments can be contaminated with MPs, and terrestrial organisms, including arthropods, are predisposed to the risk of ingesting MPs. In the current study, the larvae of the paper wasp Polistes satan were fed two different doses (6 mg or 16 mg at once) of polystyrene MPs (1.43 mm maximum length), and the effects of these treatments on immature development and survival till adult emergence were studied. Ingestion of the two doses resulted in mortality due to impaired defecation prior to pupation. The survival of larvae that ingested 16 mg of MPs was significantly lower than that of the control. The ingestion of 16 mg of MPs also reduced the adult emergence (11.4%) in comparison to the control (44.4%). MPs were not transferred from the larvae to the adults that survived. These findings demonstrate that MP ingestion can be detrimental to P. satan, e.g. larval mortality can decrease colony productivity and thus the worker force, and that MPs can potentially affect natural enemies that occur in crops, such as predatory social wasps., (© 2023. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Males of euglossine bees, also known as orchid bees, are attracted to aromatic compounds and this feature has been exploited to collect them. Here we sampled orchid bee males using a rapid passive method in a Neotropical savanna ecosystem in Rio Preto State Park (PERP), southeastern Brazil. The sampling protocol consisted of 5-day surveys using scent traps at the beginning and end of the rainy seasons. PERP is inserted in a Brazilian savanna characterized by a mosaic of vegetation types, and elevational gradients. We also analyzed whether the habitat complexity and elevational gradients influence the richness and abundance of these bees. We collected a total of 996 individuals belonging to 14 species and four genera (Eufriesea Cockerell 1908, Euglossa Latreille 1802, Eulaema Lepeletier 1841, and Exaerete Hoffmannsegg 1817). Comparing our results with previous sampling protocols at PERP, higher abundance and richness were observed using traps than insect nets to survey these bees. In addition, the orchid bee fauna in PERP was successfully assessed by our rapid passive protocol, showing that this protocol seems to be useful for collecting orchid bees in open vegetation environments. We observed that the abundance of bees was lower at higher elevations, and both abundance and richness increased in more complex habitat. This may be due to the characteristics of Brazilian savannas where the lower elevations have higher habitat complexity, with more places for nest construction and resources for feeding and nesting., (© 2021. Sociedade Entomológica do Brasil.)