The maximum sizes of 83 colonies varied greatly, the biggest colony being five times the size of the smallest. Many of the colonies that failed to grow big stopped growing quite early in the summer without losing their laying queens. This suggests that selective breeding might be more profitably directed towards uniformity than towards increase in colony size. Twenty-three colonies kept with more hive space than they could occupy had an average of about 1100 bees per British comb (1400 per Langstroth comb) on the combs they were occupying. From this, and several published estimates of colony sizes, it was deduced that an average colony needs about 34 British Il-comb boxes or 3 Langstroth lO-comb boxes to accommodate its adult bees.
Sixteen fluid ounces of Rogor 40 (40% w/v of active ingredient) was applied from the air in 7 gallons of water per acre to 2 acres of a 32-acre flowering crop of turnips.
An aqueous solution of Endothion containing 0.33% of active material was applied from the air in 30 gallons of water per acre to 2 acres of 24-acre flowering crop of rape.
Eight ounces of 50% emulsifiable concentration of M.G.K. repellent 874 was mixed into the Rogor solution and applied with it to the 2 acres of crop.
Both crops were sprayed before bees from nearby apiaries commenced to visit them. Bees collected nectar and pollen extensively from the crops which were of maximum attractiveness.
No repellency was exhibited by the Rogor-M.G.K. repellent 874 mixture or by the Endothion.
Rogor proved highly toxic to field bees, althought brood was not affected. It should on no account be applied to flowering crops.
Endothion caused no bee mortality and is safe to apply to flowering brassica crops.
A five-and-a-half acre crop of flowering chou moellier was sprayed from the air with a DDT emulsion at the rate of 2 lb of 100% p.p.i. DDT in 7 gal water per acre.
1.2 lb of 100% thiodan in 7 gal water was applied from the air to one acre of a 25-acre flowering chou moellier crop.
Both sprays were applied before bees from nearby apiaries commenced to visit the crops. Bees collected nectar and pollen extensively from the crops which were of maximum attractiveness.
Honey bees were repelled by the DDT for 6 days after application, but there was no evidence that it repelled bumble bees. Some mortality accured in field bees, but it was not very high and hives were not weakened and brood was not affected.
It is considered that DDT emulsion, if applied before bees visist a flowering brassica crop, will cause only slight mortality. It should be valuable for use when a crop must be sprayed to save it from destruction by pests.
Thiodan exerted no repellency and was more lethal to field bees than DDT. Although no adverse effect on adult bees or brood was observed in the apiary it is considered that the hives would have been seriously affected if an area of more than one acre had been sprayed.
Thiodan should not be applied to flowering brassica crops.
IN 1927, Watson described the construction of a number of glass microsyringes which he had used for the instrumental insemination of queen honey-bees. The tips of these syringes were straight and the operator holds one of these syringes in line with the long axis of the queen when, introducing it into her vagina. This type of glass syringe was simplified and improved during the course of time both by Watson himself and also by Nolan and others; but really satisfactory results were infrequently obtained at this stage.
Drones had been selected for special features of their wing structure. Afterwards they were mated, by means of artificial insemination, with queen carrying similar wing features. The line "Trifolium", bred by this method, showed several characteristics with little variability. Eighteen offspring-queens of this line were placed in a mating-yard, which had no other colonies in a circle of 5.6km diameters, with carefully selected drones. Using the wing-structure as criterion one was able to demonstrate that only queens (15%) had mated with the desired drones, while the remaining queens had mated with drones of unknown origin.
In an inbred-line it also might be possible to draw conclusions about the inherance of proboscis-lengh on the basis of wing-characteristics. One has not yet succeeded in the direct selection in drones for outstanding proboscis-lengh.
Queen honeybee have hitherto been found resistant to Malpighamoeba mellificae. For example 516 queens were examined by the author in1954-61, and none was infected. He has now found amoeba cysts in 3 out of 7 dead queens wintered in cages with attendant workers (instead of in a colony). Reasons for this difference between queens free in colonies and caged in incubators are discussed.
A community of honeybees is an integrated group, the members of which can distinguish other members from intruders. Individual bees can pass on detailed information about the nature and location of food sources ; they will produce a new queen only when the old one is no longer satisfactory. These different functions are discussed and illustrated in this article ; the discussion of queen rearing is made particularly appropriate by the recent discovery of the chemical nature of queen substance. The photographs are by Treat Davidson.
A study of sexual maturity of the drone honey bee was made to learn reasons for differences in maturity among drones of equal age. Maturity of the drones was judged by the number of spermatozoa in the seminal vesicles and vasa deferentia as determined by an improved counting technique.
At 93° F., drones caged without worker bees attained maturity at about the same rate and to the same level as those allowed free flight or caged in a nursery colony. Drone maturity was retarded slightly at 88° F. and seriously at 83° F. At the highest temperature the drones matured normally when fed honey syrup containing pollen or royal jelly (4 percent by weight) or on plain syrup. The retarding effect of the 83° temperature appeared to be offset in part by the presence of royal jelly in the diet.
Während Übereinstimmung darüber erreicht worden ist, dass die Arbeitsbienen eine ovarienhemmende Substanz von ihren Königinnen erhalten, ist es weder klargestellt worden, wie diese Substanz unter die Arbeitsbienen verteilt wird, noch ob die Königin eine psychische Wirkung auf sie ausübt.
Wenn die Versuchsresultate vonVoogd undButler sowie die Resultate dieser Arbeit zusammen betrachtet werden, scheint es klar, dass ein Extrakt dieser Substanz, wenn er an weisellose Arbeiterinnenverfüttert wird, eine deutliche Hemmwirkung auf die Ovarienentwicklung ausübt. Die Versuchsresultate deuten jedoch darauf hin, dass diese Substanz wirkungsvoller ist, wenn sie den Arbeitsbienen auf dem Körper einer toten Biene, oder dem Modell einer Biene, dargeboten wird, als wenn man sie dem Futter beimischt. Es scheint aber unwahrscheinlich, dass dies auf eine psychische Reizwirkung zurückzuführen ist
1. The flower constancy of honeybees on successive days has been studied by removing and identifying pollen collected by marked pollen-gatherers. Removing pollen from the bees decreased their tendency to collect it later; chilling the bees before marking did not influence their foraging behaviour; neither treatment affected their constancy to the kind of pollen collected. No sequence of nectar or pollen collection with age of bee, was found. 2. In each experiment most of the bees collected only a few of the pollens available to them. Bees collecting the most common pollens tended to be the most constant. In general, the proportion of bees collecting their original pollen decreased as the number of foraging days increased, and only about half were doing so after 1 week; the rate of decrease differed in different experiments. No bee regularly collected different pollens at different times of the day. When the pollen they were accustomed to collect was unavailable for a day, most foraged for nectar only or remained at home. Most bees that changed to another pollen probably did so when the pollen they had previously collected was scarce or unattractive for longer periods. 3. About 6% of the loads each contained more than one species of pollen. Bees that collected mixed loads were more inclined to do so later; probably they were dissatisfied with the crops they were working and were sampling others. 4. When a colony was moved to another site with a similar flora...