Canadian Water and Wastewater Association

Abstract Recent declines in the health of honey bee colonies used for crop pollination pose a considerable threat to global food security. Foraging by honey bee workers represents the primary route of exposure to a plethora of toxins and pathogens known to affect bee health, but it remains unclear how foraging preferences impact colony-level patterns of stressor exposure. Resolving this knowledge gap is crucial for enhancing the health of honey bees and the agricultural systems that rely on them for pollination. To address this, we carried out a national-scale experiment encompassing 456 Canadian honey bee colonies to first characterize pollen foraging preferences in relation to major crops, then explore how foraging behaviour influences patterns of stressor exposure. We used a metagenetic approach to quantify honey bee dietary breadth and found that bees display distinct foraging preferences that vary substantially relative to crop type and proximity, and the breadth of foraging interactions can be used to predict the abundance and diversity of stressors a colony is exposed to. Foraging on diverse plant communities was associated with increased exposure to pathogens, while the opposite was associated with increased exposure to xenobiotics. Our work provides the first large-scale empirical evidence that pollen foraging behaviour plays an influential role in determining exposure to dichotomous stressor syndromes in honey bees.Significance StatementInsect-mediated pollination is an important ecological process that is crucial for food production. Managed honey bee colonies are one of the most important insect pollinators, but their health has been under threat from a variety of stressors. Bee workers are primarily exposed to stressors while foraging and understanding how bee foraging preferences are related to exposure risk could provide pivotal information to improve management efforts. Here, we studied honey bee foraging preferences in relation to prominent Canadian crops and across a gradient of modified environments. We found that honey bees show distinct, measurable foraging preferences and that dietary diversity is a strong predictor of the stressors that colonies are exposed to.

Simple SummaryThe mite Varroa destructor is considered the most damaging parasite of honey bees worldwide. Beekeepers use synthetic chemical products to control mite infestations in colonies, but the parasites soon develop resistance to them, which compromises their control. One alternative control strategy is the development of Varroa-resistant honey bees. Therefore, a breeding program was initiated to select for lower and higher rates of Varroa-population growth (LVG and HVG, respectively) and deformed wing virus (DWV) levels, which is transmitted by the mites. After two years of bidirectional selection, LVG colonies had Varroa population increases over the summer of 1.7 fold compared to 9.6 fold for HVG colonies. Additionally, HVG colonies had higher mite infestation rates in adult bees compared to LVG colonies. DWV presence and levels were higher in HVG colonies than in LVG colonies and winter mortality rates were 26% and 14% for the HVG and LVG bee types, respectively. The results of this study thus far indicate that selection for LVG may result in colonies with lower Varroa infestation rates, lower prevalence, and levels of DWV and higher colony winter survivorship. Future work will focus on determining mechanisms responsible for genetic differences and in identifying genes associated with Varroa-resistance in honey bees.After two years of bidirectional selection for low and high rates of Varroa destructor population growth (LVG and HVG, respectively) in honey bee (Apis mellifera) colonies in Ontario, Canada, significant differences between the two genotypes were observed. LVG colonies had V. destructor population increases over the summer of 1.7 fold compared to 9.6 fold for HVG colonies by Generation 2. Additionally, HVG colonies had significantly higher mite infestation rates in adult bees compared to LVG colonies for both selected generations. DWV prevalence and levels were significantly higher in HVG colonies than in LVG colonies in Generation 1 but not in Generation 2. Winter mortality rates of Generation 1 colonies were significantly different at 26% and 14% for the HVG and LVG genotypes, respectively. The results of this study thus far indicate that selection for LVG may result in colonies with lower V. destructor infestation rates, lower prevalence, and levels of DWV and higher colony winter survivorship. Future work will focus on determining what mechanisms are responsible for the genotypic differences, estimating genetic parameters, and molecular analyses of the genotypes to identify candidate genes associated with resistance to V. destructor and DWV that could potentially be used for marker-assisted selection.

Nosema ceranae is an emerging pathogen of the western honey bee (Apis mellifera L.), and thus its seasonality and impact on bee colonies is not sufficiently documented for North America. This study was conducted to determine the infection intensity, prevalence, and viability of N. ceranae in >200 honey bee colonies during spring, summer, and fall, in a North American region. We also determined the relationship of N. ceranae infections with colony populations, food stores, bee survivorship, and overwinter colony mortality. The highest rates of N. ceranae infection, prevalence, and spore viability were found in the spring and summer, while the lowest were recorded in the fall. N. ceranae spore viability was significantly correlated with its prevalence and infection intensity in bees. Threshold to high levels of N. ceranae infections (>1,000,000 spores/bee) were significantly associated with reduced bee populations and food stores in colonies. Furthermore, worker bee survivorship was significantly reduced by N. ceranae infections, although no association between N. ceranae and winter colony mortality was found. It is concluded that N. ceranae infections are highest in spring and summer and may be detrimental to honey bee populations and colony productivity. Our results support the notion that treatment is justified when infections of N. ceranae exceed 1,000,000 spores/bee.

This issue of Waterlines examines three very different themes: the involvement of China in the water and sanitation sector in Africa; the performance of rural water supplies delivered by handpumps; and the question of how to pay – and who should pay – for the full costs of water services.

African countries have a lot to gain from the first international public health treaty. The Framework Convention on Tobacco Control (FCTC) was adopted in May 2003 by 168 member countries at the World Health Assembly. The African delegation demonstrated and put forth a strong, united front throughout the series of sessions which comprised the negotiation process. There are a number of considerable obstacles and challenges particular to this region of the world which makes it difficult to put tobacco control on the African agenda. Only a solid civil society mobilisation movement could serve as a worthy adversary to take on such a challenge. NGOs, such as the Framework Convention Alliance, provide assistance and should continue to support the activities of some of the key players who are still working in isolation on the continent. These organisations can also play a vital role by continuing to favour the provision of access to the available data and information which only exists in English so that the language barrier no longer remains a hindrance to the protection of the health of citizens in Francophone African countries.

SummaryA psychoanalytical approach to the causation and treatment of the hyperactive child is given. It is hypothesized that hyperactivity in children is the overt manifestation of a distortion in the mother‐child relationship which is latent. Clinical material and theory are presented from the psychoanalytical treatment of a child and an adult. This is then extrapolated to show that using these theories of brief intervention can change this overt symptom of hyperactivity and reveal the latent meaning ‐ that it is, in Fact, a disturbance in the mother herself, so enabling the mother to have the treatment she needs.

Organochloro pesticides and polychlorobiphenyls (PCB) are amongst the most toxic anthropogenic compounds presently found in the environment. In the case of the St-Lawrence river in Eastern Canada, the concentrations of both these polluants has been shown to be higher in water, sediments and fish from the stretch of the river upstream from the island of Orleans than those from samples taken downstream in the St-Lawrence estuary. In certain hot spots such as the run of the river at Montreal and the St-Louis and St-Francois lakes, the measured PCB concentrations in fish (11 species) were as high as 15 ppm; present canadien legislation sets the maximum permissible level for fish destined for human consumption at 2 ppm. In both the estuary and the gulf of the St-Lawrence organochloro pesticide and PCB concentrations are lower and more uniformily distributed than those found upstream; one consequently finds relatively low levels of these compounds in the fish populations sampled downstream from the island of Or...