Register for newsletter
Depiction:
by AURORE AVARGUÈS-WEBER
Despite having a tiny brain with 100,000 times fewer neurons than ours, bees possess remarkable cognitive abilities. These hymenopterans can count, master concepts, reason by categories… and are even faster than great apes in certain tasks!
Our hives are severely affected by winter mortality. This cannot be attributed solely to beekeeping practices—far from it; however, in such a context, the only thing the beekeeper can do is to implement everything possible to ensure that colonies have, from the very beginning of spring, the vitality required for a strong resumption of brood rearing. The time when bees could develop almost on their own is over, and we do not know whether it will ever return. We therefore need to refine our practices in order to give colonies the best possible chances. This means considering the entire economy of the hive, starting as early as the beginning of July.
The mānuka (Leptospermum scoparium), also called the New Zealand tea tree in English because its leaves can be used to make tea, is an evergreen perennial shrub belonging to the family Myrtaceae (the same family as eucalyptus and myrtle). It has irregularly branched shoots, and its leaves are small, variably shaped, and aromatic. During flowering, mānuka produces five-petaled flowers that may be white, pink, or red, followed by fruits in the form of round, woody capsules that persist on the plant for many months.
Young bees aged 12–19 days (wax-producing bees)* produce small wax scales using their wax glands, which are located in the last four abdominal segments. The process of wax production is complex.
The pavilion apiary dates back to the 19th century; its design was intended for storing baskets and hives with rear access. The apiary was meant to protect bees from wind, rain, and theft. The “Swiss” rear-access hive remains the most common management system in German-speaking Switzerland. Outside Switzerland, beekeeping is practiced mainly using multi-super hives.
In nature, bees rear queens in spring during swarming in order to multiply colonies. They also rear queens in other situations, for example when the queen no longer performs satisfactorily after several years of egg-laying, or when the queen is accidentally lost. In these particular cases, queen rearing is not associated with swarming.
Insects are not insensitive automatons: bees, wasps, flies, or ants display remarkable cognitive and emotional capacities under laboratory conditions.
Recent experiments suggest that bumblebees may experience optimism, joy, and possibly even pain. These findings raise important ethical questions concerning the treatment of insects in laboratory settings, their breeding, and the use of pesticides.
When a bee changes its role in the hive, its DNA adapts
Bees each perform a specific but flexible role within the hive. Older individuals may, if necessary, take over tasks usually carried out by younger bees. Until now, it was unknown that such behavioural changes are accompanied by adaptations at the DNA level. Each role is in fact associated with its own distinct methylation pattern.
In 2019, it came as a surprise to learn that the Varroa mite does not feed on the bees’ haemolymph but pierces their cuticle in order to ingest the so-called fat body (► see article).
Research is progressing very rapidly, and today it is known that the saliva of the adult Varroa mite allows it to keep the opening it has pierced through the membrane of the nymph or the imago wide open, in order to liquefy and then suck up the fat body. A salivary enzyme (chitinase) appears to reduce the bee’s immune defences and to play an important role in the survival of the Varroa mite … it is therefore natural to envisage blocking this enzyme as a future strategy in the fight against this deadly parasite …
Those who have already used the excuse that “housekeeping is not in my DNA” to try to avoid this chore may not have been entirely wrong. Indeed, at least in honey bees, certain shortcomings in hive hygiene appear to be linked to the overexpression of genes that impairs the detection of odors released by diseased or dead larvae.
by ALAIN SATABIN
As early as Antiquity, mathematicians observed that the shape of honeycomb cells in beehives optimizes the ratio between available volume and the amount of wax used. Demonstrating this, however, is another matter … one that has still not been fully resolved.
The deformed wing disease virus (DWV) is one of the most widespread viruses in Apis mellifera and one of the least virulent. In the absence of facilitating factors, it causes only a covert infection, that is, an infection without clinical signs.
It sticks, it stains, and we sometimes curse it when inspecting our beehives; yet it gives beekeeping one of the fragrances that contribute to its charm and is also an increasingly sought-after product, representing a growing source of income for beekeepers. Although omnipresent in our hives, propolis is the result of a harvest and a processing effort that is anything but simple for the bee. A demanding but indispensable task; for this resinous substance, whose medicinal properties have been appreciated since Antiquity, fulfils multiple functions within the colony.
by ELIZABETH TIBBETTS AND ADRIAN DYER
Recognizing the facial features of conspecifics does not require a brain as complex as one might imagine: some insects, notably bees, are remarkably adept at this.
Chemical control of harmful organisms has been known for millennia. The application of sulfur, lead, or arsenic was already practiced in ancient Greece. Closer to our time, the insecticidal properties of tobacco (nicotine) were known as early as the 17th century. In the 19th century, chemistry made major advances, and new copper sulfate–based compounds made it possible to control fungal diseases of grapevines. In the 20th century, mercury salts began to be used for seed treatment. Because of their toxicity, these substances were quickly banned.
In beekeeping supply stores, frames are available pre-assembled with or without wax, as well as frames to be assembled. For a pre-assembled frame with wax, a minimum cost of CHF 10 should be expected.
The art of economy (Janine Kevits)
Winter represents a formidable challenge for fauna, as it must cope both with cold temperatures and with food scarcity. Some insects have “chosen” to avoid it by migrating to warmer regions; this is the case, for example, of the painted lady butterfly. Others concentrate their chances of survival on a few individuals—reproductives that are abundantly nourished during the favorable season and whose task is to found a new colony on their own the following spring; this is the strategy of wasps, hornets, and other solitary bees. The honey bee, by contrast, has found a different path: it is the powerful organization of the colonies it forms that enables it to meet this challenge, by implementing two means that are entirely original in the insect world—on the one hand, the storage of reserves, and on the other, the reorganization of the colony to form the winter cluster, a system characterized by the absence of brood and by modes of functioning that differ fundamentally from those of the summer colony.
Biotechnical control methods are increasingly being promoted in the fight against varroosis. Among these, techniques that induce significant interruptions in brood development are often discussed. However, such methods are still rarely used by beekeepers, except on an experimental basis. This article analyses the relevance of brood interruption and the different techniques derived from it.
Below, you can observe in real time the variations in hive weight and the changes in colony temperature in different apiaries located in the plain and on the slope of the right bank of the Rhône.