John Kefuss

John Kefuss

Doctor of Philosophy

About

24
Publications
4,169
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188
Citations

Publications

Publications (24)
Preprint
Full-text available
The ‘suppressed in-ovo virus infection’ trait (SOV) was the first trait applied in honey bee breeding programs aimed to increase resilience to virus infections, a major threat for colony survival. By screening drone eggs for viruses, the SOV trait scores the antiviral resistance of queens and its implications for vertical transmission. In this stud...
Article
Full-text available
Parasitism is expected to select for counter‐adaptations in the host: driving a coevolutionary arms race. However, human interference between honey bees (Apis mellifera ) and Varroa mites removes the effect of natural selection and restricts the evolution of host counter‐adaptations. With full‐sibling mating common among Varroa , this can rapidly s...
Article
Full-text available
Social insect colonies possess a range of defences which protect them against highly‐virulent parasites and colony collapse. The host‐parasite interaction between honey bees (Apis mellifera) and the mite Varroa destructor is unusual, as honey bee colonies are relatively poorly‐defended against this parasite. The interaction has existed since the mi...
Article
Full-text available
A survival field test was initiated in 1999 to observe the effects of no treatment against Varroa destructor on European honey bee colony survival. After losses of over two-thirds of the 268 original colonies, new colonies were made from the survivors. In 2002, genetic material from these survivors was bred into an independent group of 60 colonies....
Article
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In 1993 at Le Born near Toulouse, France 12 Apis mellifera intermissa queens from Tunisian colonies that had been naturally selected for tolerance to varroosis were tested against 12 unselected Apis mellifera carnica queens. We wished to determine if the tolerance of the intermissa queens was genetic in origin or simply due to specific local condit...
Article
Full-text available
Hemolymph samples from adult bees that had completed their pupal development and emergence in a 7 Tesla field contained a lower percentage of glucose than controls, indicating that trehalase enzyme activity in honey bees is reduced in strong magnetic fields. Significantly more phospholipids were found in the intestines of magnetic field-exposed bee...
Article
Full-text available
In Maldonado (Uruguay) trcten trotz des langjiihrigen Verzichts auf chemische Behandlungsrnittel keine durch Varroatose bedingte Verluste an Bienenviilkern auf, Wie morphometrische Analysen von Bienen aus dieser Population zeigen, handelt es sich bei diesen Bienen um Bastarde verschiedener europaischer Bienenrassen. Von Mai bis Oktober 1993 wurden...
Article
Full-text available
A graphical method is used to calculate the inbreeding coefficient of honey bees produced by instrumentally inseminating a queen with either sperm from a single drone, several drones from the same queen or several drones from different queens
Article
Full-text available
The effects of increasing and decreasing photoperiods on the honeybee Apis mellifera were studied under flight-room conditions. Brood was reared under both long-day and short-day photoperiods, indicating that there is no critical day length that has to be attained before brood rearing can begin. Honeybees reacted to increasing photoperiods by reari...
Thesis
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Influence of photoperiod on honey bee brood rearing and flight behavior
Thesis
Full-text available
Influence of photoperiod on honey bee brood rearing and flight behaviour
Research
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This film shows landing, take-off and collecting behavior on Melilotus albus and Solidago canadensis. Landing is characterized by an extension of the legs away from the body. Initial contact is usually made with the first pair of legs. On the plant the bee is guided from one small floret to the next with aid of the antennal flagella. A jumping move...
Research
Full-text available
This film shows the flight behaviour and wing movements of honey bees in free flight. Loading of the pollen baskets, positions of the head, antennae and legs are considered in detail. Leg spreading behaviour is characterized by extension of the third pair of legs behind and to the sides forming a V-shape with all pretarsi oriented upwards. "Face to...
Thesis
Full-text available
Influence of photoperiod on honey bee brood rearing and behaviour
Article
Full-text available
Honeybees in controlled-environment rooms developed flight activity patterns in response to the cycles of light and dark. As the photophase was lengthened, flight activity per unit time decreased, and in continuous light the diurnal rhythm faded. By altering the timing of the photophase, bees could be conditioned to high flight activity at times ot...

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