Looking for the causes of and solutions to the issue of honey bee colony losses

Abstract

Colony losses, including those induced by the colony collapse disorder, are an urgent problem of contemporary apiculture which has been capturing the attention of both apiculturists and the research community. CCD is characterized by the absence of adult dead bees in the hive in which few workers and a queen remain, the ratio between the brood quantity and the number of workers is heavily disturbed in favor of the former, and more than enough food is present. Robbing behavior and pests usually attacking the weakened colony do not occur. In the present paper, the causes of the emergence of this problem are discussed, as well as the measures of its prevention. The following factors, which lead to colony losses, are analyzed: shortage of high-quality food (pollen and honey); infestation with parasites, primarily with Varroa destructor, and mixed virus infections; bacterial infections (American and European foulbrood), fungal infections (nosemosis and ascosphaerosis) and trypanosomal infections (lotmariosis); and, finally, general management of the apiary. Certain preventive measures are proposed: (1) providing ample high-quality forage and clean water, (2) avoiding sugarisation, i.e. superfluous use of sugar syrup, (3) meeting the nutritional needs of the colony, (4) when feeding bees, taking care of the timing and the composition of diet, avoiding pure sugar syrup which in excessive quantities may induce energetic and oxidative stress, (5) when there is a shortage of natural feed – honey in the brood chamber – use sugar syrup with natural/artificial supplements to avoid protein starvation, (6) organized control of V. destructor in the colonies is obligatory due to its vector role, and (7) compliance with hygienic and sanitary measures and principles of good apiculture practice and management in apiaries. To conclude, all preventive measures are feasible in compliance with rules and regulations concerning regular spring and autumn bee health monitoring by licensed veterinarians, who can propose adequate treatments if necessary.

Contact Effect Contribution to the High Efficiency of Lithium Chloride Against the Mite Parasite of the Honey Bee

“…The first publication on the varroicidal effect of lithium salts revealed that they have high effectiveness with a systemic mode of action, exerting 100% mite mortality and low toxicity to adult bees, in artificial swarms already at a concentration of 25 mM [10,11].…”

“…Alongside novel RNAi-based approaches [9], it was observed that lithium salts may offer promising and easy-to-use chemicals for effectively treating Varroa infestation. Furthermore, treatments have been published where 100% mite mortality was found in the brood-free period with minor or no mortality of adult bees, with certain concentrations of lithium-containing chemicals [10,11]. Lithium chloride has been described as a varroicide that acts in a systemic mode of action in a wide range of concentrations [10].…”

Anti-Varroa Efficiency of Coumaphos and Its Influence on Oxidative Stress and Survival of Honey Bees

“…Given the widespread use of chemicals in all human areas of practice, the bees are not safe from exposure to various types of agropesticides [11]. In North America, for instance, hives have been found to be contaminated by 120 pesticides and their metabolites [44], the most common one being coumaphos.…”

“…When V. destructor was fi rst noticed, scientists could readily imagine that it would be a real nuisance causing a disaster to beekeeping [3]. Although some traits of the bee mite remained poorly known [4,5], later it has been recognised that besides causing a decline in the bee population in hives, it also serves as a vector to various bee pathogens [6][7][8][9][10][11]. However, recent research pointed to the fact that viruses are not decisive pathogens: it is highly probable that not they themselves, but Varroa mites are those which are of outstanding importance in producing bee pathology, given that they feed on the body fat [2], which is known to have hugely important functions: besides being a source of fat and proteins, it regulates metabolism and plays a pivotal role in the immunology of the honey bee [12,13].…”

Trypanosomatid parasite dynamically changes the transcriptome during infection and modifies honey bee physiology

“…Nevertheless, the number of managed honey bee colonies has dramatically declined across North America and Europe since 2006 1 . Although there are many potential causes for the observed declines, pathogens/parasites are considered major threats to the health of honey bees [2][3][4] . There are different kinds of honey bee pathogens/parasites, such as viruses, bacteria, fungi, protozoans, and mites 2 .…”