Selenium Toxicity to Honey Bee (Apis mellifera L.) Pollinators: Effects on Behaviors and Survival

We know very little about how soil-borne pollutants such as selenium (Se) can impact pollinators, even though Se has contaminated soils and plants in areas where insect pollination can be critical to the functioning of both agricultural and natural ecosystems. Se can be biotransferred throughout the food web, but few studies have examined its effects on the insects that feed on Se-accumulating plants, particularly pollinators. In laboratory bioassays, we used proboscis extension reflex (PER) and taste perception to determine if the presence of Se affected the gustatory response of honey bee (Apis mellifera L., Hymenoptera: Apidae) foragers. Antennae and proboscises were stimulated with both organic (selenomethionine) and inorganic (selenate) forms of Se that commonly occur in Se-accumulating plants. Methionine was also tested. Each compound was dissolved in 1 M sucrose at 5 concentrations, with sucrose alone as a control. Antennal stimulation with selenomethionine and methionine reduced PER at higher concentrations. Selenate did not reduce gustatory behaviors. Two hours after being fed the treatments, bees were tested for sucrose response threshold. Bees fed selenate responded less to sucrose stimulation. Mortality was higher in bees chronically dosed with selenate compared with a single dose. Selenomethionine did not increase mortality except at the highest concentration. Methionine did not significantly impact survival. Our study has shown that bees fed selenate were less responsive to sucrose, which may lead to a reduction in incoming floral resources needed to support coworkers and larvae in the field. If honey bees forage on nectar containing Se (particularly selenate), reductions in population numbers may occur due to direct toxicity. Given that honey bees are willing to consume food resources containing Se and may not avoid Se compounds in the plant tissues on which they are foraging, they may suffer similar adverse effects as seen in other insect guilds

Occurrence of antibiotic resistant bacteria in waste site of Ede south west Nigeria

Abstract: Analysis of antibiotic resistant bacteria from composted waste site soil samples for two seasons were done, using prepared diagnostic test agar and direct sensitivity tests. All major isolated bacteria were subjected to various antibiotics. Concurrent positive and negative tests were simultaneously studied. Results show relatively high resistant and sensitive bacteria in both seasons. In wet seasons, the Bacillus cereus concentrations are considerably reduced than in the dry. In the dry seasons, Bacillus cereus was sensitive to Erythromycin (ERY) and Tetracycline (TET) and slightly resistant to Ampicillin (AMP), Chloramphenicol (CHL), Cloxacillin (CXC) and water (CNT). In the wet season, identified Pseudomonas aeruginosa was moderately resistant to Streptomycin (STR) and Tetracycline and remained resistant to Ampicillin, Cotrimoxazole (COT), Nitrofurantion (NIT) and water (CNT). The implications for human health are discussed